[Federal Register Volume 85, Number 248 (Monday, December 28, 2020)]
[Rules and Regulations]
[Pages 85380-85437]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-26264]



[[Page 85379]]

Vol. 85

Monday,

No. 248

December 28, 2020

Part III





Department of Transportation





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Pipeline and Hazardous Materials Safety Administration





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49 CFR Parts 107, 171, 173, et al.





Hazardous Materials: Miscellaneous Amendments Pertaining to DOT-
Specification Cylinders; Final Rule

Federal Register / Vol. 85 , No. 248 / Monday, December 28, 2020 / 
Rules and Regulations

[[Page 85380]]


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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Parts 107, 171, 173, 178 and 180

[Docket No. PHMSA-2011-0140 (HM-234)]
RIN 2137-AE80


Hazardous Materials: Miscellaneous Amendments Pertaining to DOT-
Specification Cylinders

AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), 
Department of Transportation (DOT).

ACTION: Final rule.

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SUMMARY: PHMSA is amending the Hazardous Materials Regulations (HMR) to 
revise certain requirements applicable to the manufacture, use, and 
requalification of DOT-specification cylinders. PHMSA is taking this 
action in response to petitions for rulemaking submitted by 
stakeholders and agency review of compressed gas cylinder regulations. 
Specifically, PHMSA is incorporating by reference or updating the 
references to several Compressed Gas Association publications, amending 
the filling requirements for compressed and liquefied gases, expanding 
the use of salvage cylinders, and revising and clarifying the 
manufacture and requalification requirements for cylinders.

DATES: 
    Effective date: January 27, 2021.
    Incorporation by reference date: The incorporation by reference of 
certain publications listed in this rule is approved by the Director of 
the Federal Register as of January 27, 2021. The incorporation by 
reference of other publications listed in this rule were previously 
approved by the Director of the Federal Register as of January 1, 2004 
(ASTM E 8-99 and Welding Aluminum: Theory and Practice, Fourth Edition) 
and May 11, 2020 (Transport Canada TDG Regulations).
    Compliance Date: Unless otherwise specified, compliance with the 
amendments adopted in this final rule is required beginning December 
28, 2021.

FOR FURTHER INFORMATION CONTACT: Eamonn Patrick, Standards and 
Rulemaking Division, and Mark Toughiry, Mechanical Engineer, 
Engineering and Research Division, Pipeline and Hazardous Materials 
Safety Administration, U.S. Department of Transportation, 1200 New 
Jersey Avenue SE, Washington, DC 20590, at (202) 366-8553.

SUPPLEMENTARY INFORMATION: 
I. Executive Summary
II. ANPRM Background
III. NPRM Background
IV. Petitions for Rulemaking and Comments Received
V. Special Permits and Comments Received
VI. Agency Initiated Editorial Corrections
VII. Section-by-Section Review
VIII. Regulatory Analyses and Notices
    A. Statutory/Legal Authority for This Final Rule
    B. Executive Order 12866 and DOT Policies and Procedures for 
Rulemakings
    C. Executive Order 13771
    D. Executive Order 13132
    E. Executive Order 13175
    F. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Procedures and Policies
    G. Paperwork Reduction Act
    H. Regulation Identifier Number (RIN)
    I. Unfunded Mandates Reform Act of 1995
    J. Environmental Assessment
    K. Privacy Act
    L. Executive Order 13609 and International Trade Analysis
    M. National Technology Transfer and Advancement Act

I. Executive Summary

    Cylinders filled with a Class 2 hazardous material (gas) or other 
hazardous materials and offered for transportation must comply with 
various requirements of the Hazardous Materials Regulations (HMR; 49 
CFR parts 171-180). These include 49 CFR part 173, subpart G, which 
sets forth the requirements for preparing and packaging gases; 49 CFR 
part 178, subpart C, which sets forth the specifications for cylinders 
(i.e., how they should be constructed); and 49 CFR part 180, subpart C, 
which sets forth the requirements for repair, maintenance, and periodic 
requalification of cylinders. Additionally, cylinders must meet other 
requirements in the HMR, such as regulations that address the modal 
requirements on cylinders in transportation including general handling, 
loading, unloading, and stowage.
    PHMSA (also referred to herein as ``we'' or ``us''), in response to 
petitions for rulemaking submitted by stakeholders and an Agency 
initiated review of the regulations, is making changes to the HMR, 
including but not limited to the following: Incorporating by reference 
or updating references to several Compressed Gas Association (CGA) 
publications; amending the filling requirements for compressed and 
liquefied gases; expanding the use of salvage cylinders; and revising 
and clarifying the manufacture and requalification requirements for 
cylinders. This final rule is also presenting minor and miscellaneous 
regulatory editorial corrections. These revisions are collectively 
intended to result in a net reduction of regulatory burdens while 
maintaining or enhancing the existing level of safety of hazardous 
materials transported in cylinders. Based on the regulatory impact 
analysis conducted in support of this final rule, PHMSA estimates that 
adoption of this final rule will result in net cost savings of 
approximately $.70 million over 10 years, or $70,000 annualized 
(undiscounted).

II. ANPRM Background

    On May 29, 2012, PHMSA published an Advance Notice of Proposed 
Rulemaking (ANPRM) to obtain public comment from those likely to be 
affected by the possible adoption of ten petitions for rulemaking and 
three special permits (SP) into the HMR (77 FR 31551). Commenters 
included cylinder manufacturers, cylinder requalifiers, independent 
inspection agencies, commercial establishments that own and use DOT-
specification cylinders and UN pressure receptacles, and individuals 
who export non-UN/ISO compressed gas cylinders. The ANPRM proposed 
adopting the petitions for rulemaking and special permits to update and 
expand the use of currently authorized industry consensus standards; 
revise the construction, marking, and testing requirements of DOT 4-
series cylinders; clarify the filling requirements for cylinders; 
discuss the handling of cylinders used in a fire suppression system; 
and revise the requalification and condemnation requirements for 
cylinders.
    The ANPRM comment period closed on August 27, 2012. PHMSA received 
comments from 13 stakeholders, including compressed gas and/or cylinder 
manufacturers, cylinder testers, and trade associations representing 
the compressed gas industry or shippers of hazardous materials. Most 
comments either answered questions PHMSA posed in the ANPRM or 
responded to multiple petitions and/or special permits. Regarding the 
petitions, the comments received were mostly supportive for all of the 
petitions, with the exception of P-1515. PHMSA received four comments 
regarding the special permits and all supported their adoption into the 
HMR. A list of the commenters, along with the related Docket ID Number, 
is shown in Table 1 below:

[[Page 85381]]



                           Table 1--ANPRM Commenters and Associated Comment Docket No.
----------------------------------------------------------------------------------------------------------------
                          Company                                               Docket ID No.
----------------------------------------------------------------------------------------------------------------
Air Products and Chemicals, Inc............................  PHMSA-2011-0140-0004
                                                             PHMSA-2011-0140-0008
                                                             PHMSA-2011-0140-0018
Bancroft Hinchley..........................................  PHMSA-2011-0149-0024
Barlen and Associates, Inc.................................  PHMSA-2011-0140-0019
City Carbonic, LLC.........................................  PHMSA-2011-0140-0029
Compressed Gas Association (CGA)...........................  PHMSA-2011-0140-0005
                                                             PHMSA-2011-0140-0012
                                                             PHMSA-2011-0140-0013
                                                             PHMSA-2011-0140-0020
Council on Safe Transportation of Hazardous Articles, Inc.   PHMSA-2011-0140-0026
 (COSTHA).
CTC Certified Training.....................................  PHMSA-2011-0140-0001
                                                             PHMSA-2011-0140-0023
                                                             PHMSA-2011-0140-0030
HMT Associates.............................................  PHMSA-2011-0140-0002
                                                             PHMSA-2011-0140-0021
Hydro-Test Products, Inc...................................  PHMSA-2011-0140-0017
Manchester Tank............................................  PHMSA-2011-0140-0016
Norris Cylinder............................................  PHMSA-2011-0140-0025
SodaStream USA, Inc........................................  PHMSA-2011-0140-0027
Worthington Cylinder Corporation...........................  PHMSA-2011-0140-0028
----------------------------------------------------------------------------------------------------------------

    Please see the HM-234 notice of proposed rulemaking (NPRM) 
published on July 26, 2016 (81 FR 48978) for a detailed discussion of 
comments made to the ANPRM.

III. NPRM Background

    On July 26, 2016, PHMSA published an NPRM to obtain public comment 
on changes proposed to the HMR (81 FR 48978). The NPRM addressed 20 
total petitions, one special permit, and several PHMSA-initiated 
editorial changes intended to clarify HMR requirements. After 
publication of the NPRM, PHMSA received comments from 44 stakeholders 
on the proposed changes. A table of commenters is shown in Table 2 
below:

                           Table 2--NPRM Commenters and Associated Comment Docket No.
----------------------------------------------------------------------------------------------------------------
                          Company                                               Docket ID No.
----------------------------------------------------------------------------------------------------------------
Alaska Airlines............................................  PHMSA-2011-0140-0036
Amerex.....................................................  PHMSA-2011-0140-0061
AmeriGas Propane, L.P......................................  PHMSA-2011-0140-0066
Amtrol.....................................................  PHMSA-2011-0140-0063
                                                             PHMSA-2011-0140-0058
Bancroft Hinchey Inc.......................................  PHMSA-2011-0140-0071
Compressed Gas Association (CGA)...........................  PHMSA-2011-0140-0052
Council on Safe Transportation of Hazardous Articles         PHMSA-2011-0140-0083
 (COSTHA).
CTC (Certified Training Co.)...............................  PHMSA-2011-0140-0057
                                                             PHMSA-2011-0140-0042
Danko Emergency Equipment Co...............................  PHMSA-2011-0140-0044
Dow Chemical Company.......................................  PHMSA-2011-0140-0060
Entegris...................................................  PHMSA-2011-0140-0082
FIBA.......................................................  PHMSA-2011-0140-0074
                                                             PHMSA-2011-0140-0041
Fike Corporation...........................................  PHMSA-2011-0140-0077
Fire Suppression Systems Association (FSSA)................  PHMSA-2011-0140-0047
Firehouse Hydro Sales and Service..........................  PHMSA-2011-0140-0067
Ford Motor Company.........................................  PHMSA-2011-0140-0055
Galiso Incorporated........................................  PHMSA-2011-0140-0062
Hidroprob S.A..............................................  PHMSA-2011-0140-0079
HMT Associates, LLC........................................  PHMSA-2011-0140-0049
Honeywell..................................................  PHMSA-2011-0140-0084
Hydro-Test Products Inc....................................  PHMSA-2011-0140-0033
Independent Cylinder Training (ICT)........................  PHMSA-2011-0140-0068
Janus Fire Systems.........................................  PHMSA-2011-0140-0069
Kidde-Fenwal, Inc..........................................  PHMSA-2011-0140-0065
Manchester Tank............................................  PHMSA-2011-0140-0050
Wesley Scott...............................................  PHMSA-2011-0140-0080
Chart, Inc.................................................  PHMSA-2011-0140-0078
Guardian Services, Inc.....................................  PHMSA-2011-0140-0072
Joshua Blake...............................................  PHMSA-2011-0140-0059
Jeff Elliot................................................  PHMSA-2011-0140-0043
David Felkins..............................................  PHMSA-2011-0140-0035
W Andrews..................................................  PHMSA-2011-0140-0034

[[Page 85382]]

 
Katherine Bowman...........................................  PHMSA-2011-0140-0032
National Association of Fire Equipment Distributors........  PHMSA-2011-0140-0053
National Propane Gas Association...........................  PHMSA-2011-0140-0070
Noble Gas Solutions........................................  PHMSA-2011-0140-0045
Northeast Pressure Vessel Testing..........................  PHMSA-2011-0140-0046
Praxair....................................................  PHMSA-2011-0140-0073
Quality Safety Solutions, LLC..............................  PHMSA-2011-0140-0040
Scuba Do...................................................  PHMSA-2011-0140-0081
Steve Gentry...............................................  PHMSA-2011-0140-0086
The Chemours Company FC, LLC...............................  PHMSA-2011-0140-0054
Thunderbird Cylinder.......................................  PHMSA-2011-0140-0037
Worthington Cylinder.......................................  PHMSA-2011-0140-0064
----------------------------------------------------------------------------------------------------------------

    Most comments addressed more than one change proposed in the NPRM. 
The comments are discussed below in the context of each petition or 
other proposed changes it addresses.

IV. Petitions for Rulemaking and Comments Received

    Table 3 lists the petitions included in the docket for this 
proceeding. The NPRM addressed 20 total petitions. The table below 
provides the petition number, the petitioner's name, the docket number 
on www.regulations.gov, a summary of the request(s), the affected 49 
CFR sections, whether PHMSA proposed to adopt the petition in the NPRM, 
and the decision to adopt, adopt in part, or not adopt the petition in 
this final rule.

                                                                Table 3--Petition Summary
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Petition No.         Petitioner               Docket No.                  Summary           Affected sections  Proposed to adopt?       Adopted?
--------------------------------------------------------------------------------------------------------------------------------------------------------
P-1499.............  Compressed Gas      PHMSA-2007-28485...........  Replace the              Sec.  Sec.          Proposed to adopt.  Adopted.
                      Association.                                     incorporated by          171.7; 172.102
                                                                       reference (IBR)          (SP 338);
                                                                       Seventh Edition of the   173.3(d)(9);
                                                                       CGA C-6 Standards for    173.198(a);
                                                                       Visual Inspection of     180.205(f)(1);
                                                                       Steel Compressed Gas     180.209(c),
                                                                       Cylinders with the       (b)(1)(iii), (d),
                                                                       revised Tenth Edition    (f), (g), (m);
                                                                       and update the           180.211(d)(1)(ii)
                                                                       appropriate references   ; 180.411(b);
                                                                       throughout the HMR.      180.510(c).
P-1501.............  Compressed Gas      PHMSA-2007-28759...........  Revise the               Sec.  Sec.          Proposed to adopt   Adopted in part.
                      Association.                                     specification            178.50, 178.51,     in part.
                                                                       requirements for 4B,     178.61, 178.68.
                                                                       4BA, 4BW, and 4E
                                                                       cylinders to provide
                                                                       clarity.
P-1515.............  Certified Training  PHMSA-2008-0101............  Adopt changes to the     Sec.  Sec.          Proposed to adopt,  Adopted in part.
                      Company.                                         requalification          180.203, 180.205,   except those
                                                                       process designed to      180.207, 180.209,   changes not
                                                                       clarify the              180.211, 180.212,   necessary because
                                                                       regulations in the       180.213, and        of incorporation
                                                                       event CGA Standard C-    180.215 and         by reference of
                                                                       1, Methods of Pressure   appendices C and    CGA C-1 under P-
                                                                       Testing Compressed Gas   E to part 180.      1626.
                                                                       Cylinders, is not
                                                                       incorporated.
P-1521.............  Compressed Gas      PHMSA-2008-0152............  Allow the use of labels  Sec.                Proposed to adopt.  n/a; addressed by
                      Association.                                     described in CGA C-7-    172.400a(a)(1)(i).                      another
                                                                       2004 on a cylinder                                               rulemaking.
                                                                       contained in an
                                                                       overpack.
P-1538.............  The Wicks Group,    PHMSA-2009-0138............  Allow Sec.               Sec.  Sec.          Not proposed to     Not adopted.
                      representing                                     173.306(a)(1) to         171.8,              adopt.
                      Jetboil Inc.                                     permit camping stove     173.306(a)(1).
                                                                       cylinders containing
                                                                       liquefied petroleum
                                                                       gas in amounts less
                                                                       than four (4) ounces
                                                                       to be shipped as
                                                                       consumer commodity
                                                                       (ORM-D). Define
                                                                       ``capacity'' in Sec.
                                                                       171.8.
P-1539.............  Matheson Tri-Gas..  PHMSA-2009-0140............  Allow DOT 3A, 3AA, 3AL   Sec.   180.209(a).  Not proposed to     Not adopted.
                                                                       cylinders in Division                        adopt.
                                                                       2.2 Services to be
                                                                       retested every 15
                                                                       years.
                                                                      Allow DOT 3A, 3AA, and
                                                                       3AL cylinders packaged
                                                                       with Division 2.1
                                                                       materials to be
                                                                       requalified every 10
                                                                       years.
P-1540.............  Compressed Gas      PHMSA-2009-0146............  Require newly            Sec.   178.35(f)..  Proposed to adopt.  Adopted.
                      Association.                                     manufactured DOT 4B,
                                                                       4BA, 4BW, and 4E
                                                                       cylinders to be marked
                                                                       with the mass weight,
                                                                       tare weight, and water
                                                                       capacity.
P-1546.............  GSI Training        PHMSA-2009-0250............  Allow cylinders used as  Sec.   173.309(a).  Proposed to adopt.  Adopted in part.
                      Services, Inc.                                   a component of a fixed
                                                                       fire suppression
                                                                       system to be
                                                                       transported under the
                                                                       exceptions applicable
                                                                       to fire extinguishers.

[[Page 85383]]

 
P-1560.............  Air Products and    PHMSA-2010-0176............  Modify the maximum       Sec.                Not proposed to     Not adopted.
                      Chemicals, Inc.                                  permitted filling        173.304a(a)(2).     adopt. Addressed
                                                                       densities for carbon                         by revisions made
                                                                       dioxide and nitrous                          under rulemaking
                                                                       oxide to include                             HM-233F [81 FR
                                                                       70.3%, 73.2%, and                            3635].
                                                                       74.5% in DOT 3A, 3AA,
                                                                       3AX, 3AAX, and 3T
                                                                       cylinders.
P-1563.............  Regulatory Affairs  PHMSA-2010-0208............  Authorize an             Sec.                n/a; We asked for   Not adopted.
                      Management                                       ``overpack'' as a        173.301(a)(9).      further comment.
                      Center--3M                                       strong outer package
                      Package                                          for cylinders listed
                      Engineering,                                     in the section, except
                      Global Dangerous                                 aerosols ``2P'' and
                      Goods.                                           ``2Q,'' marked with
                                                                       the phrase ``inner
                                                                       packagings conform to
                                                                       the prescribed
                                                                       specifications''.
P-1572.............  Barlen and          PHMSA-2011-0017............  Revise the filling       Sec.  Sec.          Proposed to adopt,  Adopted, in part.
                      Associates, Inc.                                 ratio for liquefied      173.301(g)(1)(ii)   in part.
                                                                       compressed gases in      and 173.312.
                                                                       MEGCs consistent with
                                                                       Packing Instruction
                                                                       (P200) of the United
                                                                       Nations (UN)--Model
                                                                       Regulations (17th ed.
                                                                       2011), as specified in
                                                                       Sec.   173.304b; and
                                                                       prohibit liquefied
                                                                       compressed gases in
                                                                       manifolded DOT
                                                                       cylinders from
                                                                       exceeding the filling
                                                                       densities specified in
                                                                       Sec.   173.304a(a)(2).
P-1580.............  HMT Associates....  PHMSA-2011-0123............  Require the burst        Sec.  Sec.          Proposed to adopt.  Adopted.
                                                                       pressure of the          173.301(f)(4),
                                                                       rupture disc on a        173.302(f)(2),
                                                                       cylinder ``shall not     173.304(f)(2).
                                                                       exceed 80% of the
                                                                       minimum cylinder burst
                                                                       pressure and shall not
                                                                       be less than 105% of
                                                                       the cylinder test
                                                                       pressure'' for DOT 39
                                                                       cylinders containing
                                                                       oxidizing gas
                                                                       transported by
                                                                       aircraft.
P-1582.............  Water Systems       PHMSA-2011-0135............  Revise the limited       Sec.   173.306(g).  Proposed to adopt.  Adopted.
                      Council.                                         quantity exception for
                                                                       water pump system
                                                                       tanks to authorize
                                                                       transport of tanks
                                                                       manufactured to
                                                                       American National
                                                                       Standards Institute's
                                                                       Water Systems Council
                                                                       Standard PST 2000--
                                                                       2005 (2009).
P-1592.............  Compressed Gas      PHMSA-2012-0173............  IBR CGA S-1.1, 2011      Sec.  Sec.          Proposed to adopt.  Adopted.
                      Association.                                     Pressure Relief Device   173.301(c), (f)
                                                                       Standards, Part 1,       and (g),
                                                                       Cylinder for             173.302a(c),
                                                                       Compressed Gas,          173.304a(e),
                                                                       Fourteenth Edition.      178.75(f).
P-1596.............  Chemically          PHMSA-2012-0200............  Add Class 4 and Class 5  Sec.   173.3(d)(1)  Proposed to adopt.  Adopted.
                      Speaking, LLC.                                   hazardous materials to
                                                                       the hazard classes in
                                                                       an authorized salvage
                                                                       cylinders.
P-1622.............  Worthington         PHMSA-2013-0210............  Restrict the internal    Sec.                Proposed to adopt.  Adopted in part.
                      Cylinder.                                        volume of hazardous      173.304a(a)(2)
                                                                       materials shipped in a   and (3).
                                                                       DOT-specification 39
                                                                       cylinder to not exceed
                                                                       75 cubic inches.
P-1626.............  Compressed Gas      PHMSA-2013-0265............  IBR CGA C-1-2009,        Sec.  Sec.          Proposed to adopt.  Adopted.
                      Association.                                     Methods for Pressure     171.7, 178.36,
                                                                       Testing Compressed Gas   178.37, 178.38,
                                                                       Cylinders, Tenth         178.39, 178.42,
                                                                       Edition (C-1, 2009) as   178.44, 178.45,
                                                                       a reference in 49 CFR,   178.46, 178.47,
                                                                       and provide for          178.50, 178.51,
                                                                       specific language for    178.53, 178.55,
                                                                       sections affected.       178.56, 178.57,
                                                                                                178.58, 178.59,
                                                                                                178.60, 178.61,
                                                                                                178.65, 178.68,
                                                                                                180.205, 180.209.
P-1628.............  Compressed Gas      PHMSA-2013-0278............  IBR CGA C-3-2005,        Sec.  Sec.          Proposed to adopt.  Adopted.
                      Association.                                     Reaffirmed 2011,         171.7, 178.47,
                                                                       Standards for Welding    178.50, 178.51,
                                                                       on Thin-Walled, Steel    178.53, 178.55,
                                                                       Cylinders, Seventh       178.56, 178.57,
                                                                       Edition.                 178.58, 178.59,
                                                                                                178.60, 178.61,
                                                                                                178.65, 178.68,
                                                                                                180.211.

[[Page 85384]]

 
P-1629.............  Compressed Gas      PHMSA-2014-0012............  IBR CGA C-14-2005,       Sec.  Sec.          Proposed to adopt.  Adopted.
                      Association.                                     Reaffirmed 2010,         171.7, 173.301,
                                                                       Procedures for Fire      173.323.
                                                                       Testing of DOT
                                                                       Cylinder Pressure
                                                                       Relief Device Systems,
                                                                       Fourth Edition, as a
                                                                       reference in 49 CFR.
P-1630.............  Compressed Gas      PHMSA-2014-0027............  Add the term             Sec.  Sec.          Proposed to adopt.  Not adopted.
                      Association.                                     ``recondition'' for      180.203 and
                                                                       DOT-4L welded            180.211(c) and
                                                                       insulated cylinders      (e).
                                                                       and revise language to
                                                                       clarify when a
                                                                       hydrostatic test must
                                                                       be performed on the
                                                                       inner containment
                                                                       vessel after the DOT-
                                                                       4L welded insulated
                                                                       cylinder has undergone
                                                                       repair.
--------------------------------------------------------------------------------------------------------------------------------------------------------

P-1499

    The Compressed Gas Association (CGA) submitted P-1499 requesting 
that PHMSA incorporate by reference the Tenth Edition of its 
publication C-6, dated 2005, Standards for Visual Inspection of Steel 
Compressed Gas Cylinders (CGA C-6), replacing the Seventh Edition, and 
update the appropriate references throughout the HMR. The Tenth Edition 
of the CGA C-6 provides enhanced guidance for cylinder requalifiers--
including guidance on the inspection of Multiple-Element Gas Containers 
(MEGCs) and thread inspection for cylinders used in corrosive gas 
service--and clarifies maximum allowable depths and measuring 
techniques for various types of corrosion.
    PHMSA agrees that the CGA C-6 Tenth Edition provides improved and 
updated guidance on inspecting MEGCs. After the submission of this 
petition, the Eleventh Edition of the CGA C-6, dated 2013, was made 
available. PHMSA, therefore, proposed in the NPRM to update the 
incorporated by reference version of CGA C-6 to the Eleventh Edition. 
PHMSA determined that the changes from the Tenth to the Eleventh 
Editions were minor and improved safety, while not imposing any 
additional burdens on the regulated community.
    Comments. Bancroft Hinchey, Worthington Cylinder, the National 
Association of Fire Equipment Distributors (NAFED) and CGA submitted 
comments supporting incorporation by reference of the Eleventh Edition 
of CGA C-6. Thunderbird Cylinder submitted a comment requesting 
revisions to CGA publication C-6.1, Standards for Visual Inspection of 
High Pressure Aluminum Compressed Gas Cylinders and CGA publication C-
11, Recommended Practices for Inspection of Compressed Gas Cylinders at 
Time of Manufacture.
    PHMSA response. In this final rule, PHMSA is incorporating by 
reference the Eleventh Edition of the CGA C-6, as proposed. The Tenth 
Edition of the CGA C-6 provides enhanced guidance for cylinder 
requalifiers--including guidance on the inspection of Multiple-Element 
Gas Containers (MEGCs) and thread inspection for cylinders used in 
corrosive gas service--and clarifies maximum allowable depths and 
measuring techniques for various types of corrosion. PHMSA has 
determined that the changes from the Tenth to the Eleventh Editions 
were minor and improved safety, while not imposing any additional 
burdens on the regulated community. The Eleventh edition of CGA C-6 is 
available for purchase online and will be available for public 
inspection at the Hazardous Material Information Center after 
publication of the final rule.
    Thunderbird Cylinder's comment is beyond the scope of this 
rulemaking, but we encourage Thunderbird Cylinder or other interested 
parties to reach out to CGA regarding potential revisions to its 
publications and then, if warranted, to submit separate petitions for 
rulemaking requesting that PHMSA incorporate by reference the revised 
versions of CGA C-6.1 and C-11, respectively.

P-1501

    CGA submitted P-1501 requesting that PHMSA revise the manufacturing 
requirements for DOT 4B, 4BA, 4BW, and 4E specification cylinders. CGA 
contends in their petition that the DOT 4-series welded cylinder 
manufacturing specification standards in the HMR are unclear in some 
respects and result in varied interpretations of what is required of 
manufacturers by both manufacturers and enforcement personnel. CGA 
states in the petition that their proposed changes do not present a 
significant economic impact to any single manufacturer or user, yet 
will enhance regulatory clarity, promote consistent manufacturing 
practices, and create greater uniformity between the specifications for 
DOT 4-series cylinders and the requirements for welded cylinders found 
in International Organization for Standardization (ISO) Standard 4706-
1, Gas cylinders--Refillable welded steel cylinders-Part 1: Test 
pressure 60 bar and below (ISO 4706-1), which is referenced in the UN 
Model Regulations. The HMR currently incorporates ISO 4706-1 into Sec.  
178.71 as an authorized standard for the design and construction of UN 
pressure receptacles.
    Comments. CGA submitted a comment reiterating their support for 
adoption of P-1501. Bancroft Hinchey submitted a comment supporting all 
proposed changes to the manufacturing specifications in Sec. Sec.  
178.36-178.70.
    A summary of the specific changes proposed by P-1501, the comments 
received relative to the proposed changes, if any, and PHMSA's position 
and/or action are detailed below:
    (1) Revise the requirements for DOT-specification 4B, 4BA, 4BW, and 
4E cylinders in Sec. Sec.  178.50(b), 178.51(b), 178.61(b), and 
178.68(b), respectively, to ensure material compositions and the heat 
treatment are within the specified tolerances and are of uniform 
quality as follows: (1) Require a record of intentionally-added 
alloying elements, and (2) require materials manufactured outside of 
the United States to have a ladle analysis confirmed by a check 
analysis.
    Comments. We did not receive any comments regarding either 
proposal.
    PHMSA response. The provision regarding materials manufactured 
outside the United States having a ladle analysis confirmed by a check 
analysis is not necessary because Sec.  178.35(c)(2) requires 
inspectors to verify that the material of construction meets the 
requirements of the applicable specification by: (1) Making a chemical 
analysis of each heat of material; (2) obtaining a certified chemical 
analysis

[[Page 85385]]

from the material manufacturer for each heat of material (a ladle 
analysis is acceptable); or (3) if an analysis is not provided for each 
heat of material by the material manufacturer, by making a check 
analysis of a sample from each coil, sheet, or tube. However, we do 
believe a record of intentionally added alloying elements will be 
useful for ensuring material compositions are within the specified 
tolerances. A cylinder made of material within specified tolerances is 
less susceptible to deterioration or failure from the wear and tear on 
a cylinder from pressure cycling and exposure to pressurized gases.
    PHMSA, therefore, is adopting the requirement for manufacturers to 
maintain a record of intentionally added alloying elements, as 
proposed.
    (2) Revise the pressure tests for DOT-specification 4B, 4BA, 4BW, 
and 4E cylinders in Sec. Sec.  178.50(i), 178.51(i), 178.61(i), and 
178.68(h), respectively, to permit use of the volumetric expansion 
test, a hydrostatic proof pressure test or a pneumatic proof pressure 
test.
    Given the added risk associated with pneumatic testing (i.e., using 
pressurized gas for testing) and that there are suitable alternatives 
to determine whether a cylinder has a leak at the time of manufacture, 
PHMSA did not propose to permit the use of pneumatic proof pressure 
testing in the NPRM.
    Comments. Fike Corporation, the National Propane Gas Association 
(NPGA), AmeriGas Propane, Amtrol, Worthington Cylinder (Worthington) 
and Manchester Tank (Manchester) submitted comments opposing PHMSA's 
decision to not permit the use of pneumatic proof pressure testing. 
Bancroft Hinchey and NAFED submitted comments supporting our decision 
to not permit the use of pneumatic proof pressure testing.
    PHMSA response. This final rule allows manufacturers to conduct 
pneumatic proof pressure tests, when proof pressure tests are 
authorized in part 178, subpart C. PHMSA is convinced by the comments 
from Fike, NPGA, Amerigas, Amtrol, Worthington, and Manchester that 
manufacturers currently account for the additional risks created by 
pneumatic proof pressure testing. PHMSA would like to emphasize that 
pneumatic proof pressure test systems can present increased risks to 
test personnel due to the amount of energy stored in a cylinder filled 
to test pressure with a gas. This stored energy, if released due to a 
cylinder failure, is sufficient to cause serious injury or death. 
Manufacturers must take this risk into account and develop systems to 
prevent the death or injury of their employees in the event of a 
catastrophic cylinder rupture at test pressure. The use of additional 
safety equipment such as blast shields, test cages, etc., is advisable 
to prevent possible injury to testing personnel and equipment.
    (3) Revise the physical and flattening tests and retest criteria 
for DOT-specification 4B, 4BA, 4BW, and 4E cylinders in Sec. Sec.  
178.50, 178.51, 178.61, and 178.68, respectively, for consistency. 
These revisions would clarify the location on the cylinder from which 
the test specimens are removed.
(a) Elongation Criteria
    Fike Corporation submitted a comment requesting that we review the 
proposed revisions to the elongation criteria for specimens taken from 
DOT 4B, 4BA and 4BW cylinders under Sec. Sec.  178.50, 178.51, and 
178.61, based on its opinion that we should not revise the criteria at 
this time.
    PHMSA response. We agree with Fike Corporation's comment that PHMSA 
should not revise the elongation criteria. In reviewing the proposed 
changes based on comments received, we solicited comment from Steve 
Gentry, the original submitter of the elongation criteria modification 
to CGA, to provide additional justification for changing the elongation 
requirement to 20 percent for all specimens, regardless of gauge length 
in making our final determination on the proposed language based on 
CGA's petition.
    Mr. Gentry justified the requested change based on international 
harmonization and consistency with other elongation criteria 
calculations in the HMR. However, PHMSA does not believe these 
justifications warrant making the requested change. First, changing the 
elongation requirement will not assist in harmonizing with 
international standards at this time. A review of Transport Canada 
standard B339-18 shows that Canada has not revised cylinder 
manufacturing standards to require a 20 percent elongation for all 
specimens (e.g. see CSA B339-18 5.8.3). Second, we believe that 
changing the elongation criteria will introduce confusion to the 
detriment of compliance with no measurable safety benefit. Current 
elongation criteria are well understood in the industry and we do not 
believe we have enough information at this time to make the requested 
change.
    Additionally, in response to Mr. Gentry's final justification, we 
do not believe that the current elongation criteria for two inch 
specimens conflicts with the ``24t'' formula in Sec. Sec.  
178.50(k)(2), 178.51(j)(2), and 178.61(k)(2). In Sec. Sec.  
178.50(k)(2), 178.51(j)(2), and 178.61(k)(2), cylinder manufacturers 
may choose to conduct elongation tests on cylinder specimens with a set 
length of eight inches or two inches with width not over 1.5 inches, or 
use a cylinder specimen with a gauge length of 24 times the thickness 
of the wall with width not over 6 times the thickness, commonly known 
as a ``24t'' gauge length. Cylinder specimens with a gauge length of 2 
inches must achieve elongation of at least 40 percent, while all other 
gauge lengths (i.e., the 24t gauge length) must achieve an elongation 
of at least 20 percent. Mr. Gentry identified several specific 
instances where a cylinder manufacturer utilizing the 24t gauge length 
option would use a calculated gauge length very close to 2 inches (e.g. 
a cylinder with a wall thickness of .0835 inches would, using the 24t 
formula, have a specimen 2.004 inches long) which would be subject to 
an elongation requirement of 20 percent, rather than the 40 percent 
requirement for a standard 2-inch gauge specimen. Mr. Gentry believes 
that the 20 percent elongation requirement for the 2.004 inch x .501-
inch specimen calculated using the 24t method conflicts with the 40 
percent elongation requirement for the 2 inch x 1\1/2\ inch specimen.
    A direct elongation comparison between specimens with 24t gauge 
length (GL) x 6t wide, and 2'' GL x 1\1/2\'' width, however, is not 
valid because the load resisting cross-sectional areas are not the same 
even when nearly the same gauge lengths are used for both specimens. 
Essentially the ``24t'' gauge length specimen and the 2-inch specimen 
cannot be directly compared because their cross-sectional areas are 
different; therefore, it is correct to have different elongation 
criteria even when the ``24t'' specimen is very nearly 2 inches long. 
PHMSA acknowledges that there may be room for improvement of the DOT 4-
series cylinder elongation criteria associated with the physical and 
flattening tests and plans to continue reviewing the criteria for 
possible changes.
(b) Non-Destructive Examination
    Fike Corporation submitted an additional comment opposing the 
proposed requirement to examine circumferential welds in addition to 
longitudinal welds using radioscopic or radiographic examination under 
proposed Sec.  178.61(f), indicating that it believes this is a 
significant change. Regarding Fike Corporation's comments on 
radioscopic or radiographic examination applicability, we agree.

[[Page 85386]]

The current requirements in Sec.  178.61(d)(3)(ii) require radioscopic 
or radiographic examination of the longitudinal weld only, except in 
the case of spot radioscopy or radiography. It was not our intent to 
impose new weld radioscopy or radiography requirements in this final 
rule. Therefore, in this final rule we are modifying the requirements 
in Sec.  178.61(d)(5) to clarify that radioscopic or radiographic 
examination of the circumferential weld is not required, except as part 
of spot radioscopy or radiography. Additionally, we are moving the 
proposed radiography examination language from Sec.  178.61(f) to Sec.  
178.61(d)(5) in order to improve the organization of, and therefore, 
understanding of the section.
(c) Specimen Test Failure
    In the NPRM, we proposed to amend the rejected cylinder paragraphs 
for 4B, 4BA and 4E cylinders to align them with the provisions for 4BW 
cylinders. Specifically, we proposed to add a provision to Sec. Sec.  
178.50(n), 178.51(m), and 178.68(m) that would allow two additional 
specimens to be selected from the same lot and subjected to the 
prescribed test. If either of the two specimens failed the test, the 
entire lot would be rejected.
    No rationale was presented in P-1501 for this change. Moreover, we 
received no comments on these specific provisions. We do not believe 
that a change to cylinder rejection criteria is warranted at this time 
because we do not have enough supporting information to justify the 
change, and therefore we will not amend the rejected cylinder language 
in this final rule. We may consider this action in a future rulemaking.
    (4) Revise Sec. Sec.  178.50(n), 178.51(n), and 178.61(o), and 
178.68, respectively, for DOT-specification 4B, 4BA, 4BW, and 4E 
cylinders to permit marking on the footring for cylinders with water 
capacities up to 30 pounds, instead of 25 pounds.
    We received no comments regarding this item and are adopting the 
revision as proposed.
    (5) Add additional options for the location of markings on DOT 4E 
cylinders in Sec.  178.68.
    We received no comments regarding this item and are adopting the 
addition as proposed.
    (6) Determination of Expansion.
    Related to P-1501, Worthington Cylinder submitted a comment 
requesting that we eliminate the requirement to determine expansion for 
non-spherical 4B, 4BA, and 4BW cylinders at time of manufacture. This 
comment is beyond the scope of this rulemaking. We encourage 
Worthington Cylinder or other interested parties to submit petitions on 
this issue.
    (7) Correction.
    In the review of the NPRM, PHMSA determined that we inadvertently 
replaced the word ``rejected'' with ``condemned'' in several places in 
Sec. Sec.  178.50, 178.51, 178.61, and 178.68. This was not our intent. 
In this final rule, we will maintain the HMR's existing language for 
cylinders rejected during manufacture.

P-1515

    The Certified Training Company (CTC) submitted P-1515 requesting 
that PHMSA make numerous revisions to the requirements for the 
requalification of DOT-specification cylinders found in 49 CFR part 
180, subpart C. Part 180, subpart C includes definitions for terms used 
in the subpart, references to CGA publications for the visual 
inspection of cylinders, and requirements for hydrostatically testing 
cylinders including methods to ensure the accuracy of test equipment. 
Many changes proposed in P-1515 were intended to align the requirements 
in part 180, subpart C with an industry standard for the 
requalification of gas cylinders known as CGA C-1, Methods for Pressure 
Testing Compressed Gas Cylinders (CGA C-1). CTC acknowledged that the 
preferred outcome would be to incorporate by reference CGA C-1 into 
part 180, subpart C, but the petitioner presented an option whereby 
PHMSA could adopt many of the provisions of CGA C-1 into the current 
structure of the HMR without incorporating CGA C-1.
    Many of P-1515's proposed changes were only requested in the event 
that PHMSA chose not to adopt P-1626. P-1626 requested that PHMSA 
incorporate by reference CGA C-1 into part 180, subpart C. In the NPRM, 
PHMSA proposed to incorporate CGA C-1 (Eleventh Edition) into part 180, 
subpart C in addition to the numerous changes suggested by P-1515. CTC, 
along with numerous others, submitted extensive comments regarding this 
action. In this final rule, we will incorporate the Eleventh Edition of 
CGA C-1 for the requalification of compressed gas cylinders, which 
renders many of P-1515's proposed changes moot. Please see our 
discussion of P-1626 for additional discussion of CGA C-1 and revisions 
to the structure of part 180, subpart C.
(1) Comments Related to the Incorporation by Reference of CGA C-1
(a) Definitions
    Certified Training Company (CTC) and Bancroft Hinchey submitted 
comments opposing our proposed inclusion of additional definitions for 
cylinder requalification terms in Sec.  180.203, which were intended to 
bring the HMR into alignment with CGA C-1. CTC also suggested we delete 
other long-standing definitions in Sec.  180.203 because they did not 
align with CGA C-1's definitions.
    PHMSA response. We agree with CTC and Bancroft Hinchey's comments 
to remove the definitions of ``Accuracy,'' ``Accuracy grade,'' ``Actual 
test pressure,'' ``Calibrated cylinder,'' ``Defect,'' ``Elastic 
expansion,'' ``Error,'' ``Master gauge,'' ``Percent permanent 
expansion,'' ``Permanent expansion,'' ``Reference gauge,'' 
``Rejected,'' ``Service pressure,'' ``Test pressure,'' ``Total 
expansion,'' ``Visual inspection,'' and ``Volumetric expansion test'' 
from Sec.  180.203. We are incorporating by reference CGA C-1 into the 
HMR and these terms are all defined in this industry standard; thus, 
codification of the definitions in Sec.  180.203 is redundant and this 
provides us an opportunity to reduce the size of the HMR. However, 
PHMSA has decided to keep the definition of ``condemn'' because Sec.  
180.205(i) will continue to discuss condemnation criteria in greater 
detail than CGA C-1 does and we believe maintaining the definition in 
Sec.  180.203 will increase clarity for cylinder requalifiers.
(b) Incorporation of CGA C-1 Into Sec.  180.205(g)
    CTC and Bancroft Hinchey noted that the NPRM did not incorporate by 
reference CGA C-1 into Sec.  180.205(g), which was PHMSA's stated 
intent in the NPRM preamble. Section 180.205(g) is a crucial paragraph 
for cylinder requalifications that contains instructions on how to 
conduct the pressure test that is used to requalify a cylinder for 
future use or condemn it. By incorporating CGA C-1 into Sec.  
180.205(g), we will require cylinder requalifiers to comply with the 
instructions in CGA C-1 when conducting pressure tests. These 
instructions offer more guidance and include helpful diagrams and 
examples that decrease compliance burdens compared to the current 
instructions in Sec.  180.205(g).
    PHMSA response. We agree with CTC and Bancroft Hinchey's comments. 
It was our intent to incorporate CGA C-1 for the requalification of DOT

[[Page 85387]]

specification cylinders, therefore, in this final rule we are including 
a reference to CGA C-1 (Eleventh Edition) in Sec.  180.205(g).
(c) Streamlining of Existing Regulatory Text
    CTC and CGA noted that since we proposed to adopt P-1626, there was 
an opportunity to streamline the HMR's cylinder requalification 
instructions significantly by revising Sec.  180.205(g) to require 
compliance with CGA C-1, rather than maintaining the existing 
instructions for pressure tests. CTC and CGA commented that maintaining 
two sets of instructions would generate confusion and frustration.
    PHMSA response. We agree with CTC and CGA's comments to revise 
existing Sec.  180.205(g). This final rule removes the existing 
language in the HMR on conducting volumetric expansion testing from 
Sec.  180.205(g) and replaces it with instructions to conduct 
requalification in accordance with CGA C-1. These revisions will help 
to reduce confusion and improve compliance without increasing burdens 
on the regulated community while meeting our stated intent in the NPRM 
to adopt the CGA C-1 standard as the industry standard for performance 
of inspection and testing for requalification and continued service of 
cylinders.
(d) Accuracy Requirements
    In the NPRM, PHMSA proposed to align with ISO requirements by 
requiring the pressure indicating device (PID) to meet ``Industrial 
Class 1 (<plus-minus>1% deviation from the end value).'' CGA, Hidroprob 
SA, Bancroft Hinchey, and Galiso identified this change as problematic 
because it conflicts with the accuracy grade requirements for PIDs 
found in CGA C-1.
    PHMSA response. Hidroprob S.A., Bancroft Hinchey, Galiso, and CGA's 
comments regarding device accuracy are correct, and contributed to our 
decision to not adopt the proposed changes in Sec.  180.205(g) and 
simplify requirements by adopting CGA C-1 into the section. In this 
final rule, we will not adopt the proposed changes to device accuracy 
in Sec.  180.205(g). In this final rule, we will maintain the HMR's 
current PID accuracy requirements in Sec.  180.205(g)(3)(i). Voluntary 
compliance with CGA C-1 5.3.2.2 is authorized and will meet the HMR's 
accuracy requirements for PIDs used for cylinder requalification, as 
will the practice of demonstrating accuracy through maintenance of a 
calibration certificate showing the gauge has been certified to meet 
the accuracy requirements at lower points. See discussion of PID 
accuracy in P-1626 for further information on this decision.
(e) Condemnation Criteria for Repeat Tests
    CTC and Bancroft Hinchey submitted comments requesting we revise 
the condemnation criteria for cylinders that are subjected to a 
repeated test due to equipment malfunction or operator error to 5 
percent permanent expansion, rather than 10 percent. CTC states that 
increasing the pressure by 10 percent, or 100 psig for the repeat test, 
is not enough to ensure that an unsafe cylinder exhibits a permanent 
expansion over 10 percent. Bancroft Hinchey states that an increase of 
10 percent/100psi can be insufficient to give measurable plastic 
deformation and resultant permanent expansion >10 percent due to the 
gradient of the load/extension curve immediately after yield point. An 
increase of 100psi at a (minimum) test pressure of 3000 psi (the lowest 
pressure above 3000) represents a pressure increase of only 3100/3000 = 
3.3 percent and is unlikely to give a resultant 10 percent plastic 
deformation.
    PHMSA response. We do not agree with CTC and Bancroft Hinchey's 
comments to change the condemnation criteria for cylinders in this 
case. CGA C-1 limits cylinder requalifiers to only two repeated tests 
in the event of equipment malfunction or operator error, and we do not 
believe that there is a safety justification to change the condemnation 
criteria to permanent expansion that is 5 percent of total expansion in 
cases where a repeat test is conducted. We acknowledge that repeated 
tests may result in some stretching of the cylinder, resulting in 
cylinders passing requalification that may have otherwise failed; 
however, this risk is minimized by limiting requalifiers to a maximum 
of two repeat tests in the event of equipment failure or operator 
error. Further, this provision does not authorize the retest of a 
cylinder otherwise required to be condemned by Sec.  180.205(i). The 
final rule, therefore, does not change the condemnation criteria for 
cylinders subjected to a repeat test.
(f) Letters of Interpretation
    In P-1515, CTC further requested that PHMSA rescind two letters of 
interpretation (Reference Nos. 00-0309 and 05-0087) that discuss the 
number of repeat tests allowed in the event of equipment malfunction 
and required hold time for pressure tests, respectively. Bancroft 
Hinchey supports retracting these letters of interpretation.
    PHMSA response. We agree that adopting CGA C-1 will eliminate the 
confusion regarding the number of permitted repeat tests in case of 
system failure or operator error, as well as the required pressure hold 
time, that the letters of interpretation attempted to clarify. This 
final rule supersedes the two letters of interpretation. Affected 
entities should not rely on 00-0309 and 05-0087 because they are no 
longer valid and will be removed from our website.
(2) Comments Related to Sec.  180.205
(a) Grinding and Sanding
    NPGA and Amerigas opposed the proposed changes in Sec.  
180.205(d)(4) and (f)(5) regarding grinding and sanding of cylinders. 
Bancroft Hinchey submitted a comment supporting the proposed changes in 
Sec.  180.205(d)(4).
    PHMSA response. Our intent in Sec.  180.205(d)(4) and (f)(5) is to 
address methods of cleaning or repair that remove wall thickness from 
the cylinder. Cleaning methods, regardless of the tool used, that only 
remove loose debris or paint from the cylinder while not removing wall 
thickness are not considered ``grinding.'' In this final rule we modify 
Sec.  180.205(d)(4) and (f)(5) to clarify our intent and to authorize 
grinding or sanding performed by any authorized repair facility.
(b) Reordering of Condemnation Criteria
    CTC submitted a comment requesting that we swap Sec.  
180.205(i)(1)(v) and (vi) in order to have the condemnation criteria 
for DOT 4E cylinders immediately follow the general requirements in 
Sec.  180.205(i)(1)(iv).
    PHMSA response. We do not agree with CTC's comment to re-order 
Sec.  180.205(i)(1). Changing the citations for the condemnation 
criteria section will result in increased confusion and we do not 
believe it is in the best interest of safety.
(c) Additional Condemnation Criteria
    Bancroft-Hinchey commented that we should add one additional 
criterion to Sec.  180.205(d), Conditions requiring tests and 
inspections of cylinders, for cases where a cylinder is discovered with 
incorrect markings.
    PHMSA response. We are not adopting the suggested change in 
Bancroft-Hinchey's comment. They did not provide enough information to 
make a judgement on the merits of the proposal. The public may make a 
separate petition further explaining the issue.

[[Page 85388]]

(3) Comments Related to Sec.  180.207
(a) Deletion of Sec.  180.207(a) and (b)
    Certified Training Company (CTC) submitted a comment requesting 
that we delete Sec.  180.207(a) and (b), because these instructions 
could be combined with Sec.  180.205(c).
    PHMSA response. While we agree with CTC that these paragraphs serve 
similar purposes, we do not agree with CTC's comment to delete Sec.  
180.207(a) and (b) and consolidate them into Sec.  180.205(c). The 
current structure of the HMR generally separates instructions for DOT 
specification cylinders and UN ISO pressure receptacles because of 
differences in their design and construction. These paragraphs in Sec.  
180.207 are necessary to provide enforceable instructions for shippers 
and fillers of UN pressure receptacles separately from shippers and 
fillers of DOT specification cylinders.
(b) Ultrasonic Examination for High Tensile Strength UN Pressure 
Receptacles
    CTC and Worthington submitted a comment requesting that we remove 
language from Sec.  180.207(d) that requires ultrasonic examination 
(UE) of certain UN pressure receptacles.
    PHMSA response. We do not agree with CTC and Worthington's comment 
to remove the requirement that UN cylinders with a tensile strength 
greater than or equal to 950 MPa must be requalified by UE in 
accordance with ISO 6406 in Sec.  180.207(d)(1). This requirement 
serves an important safety purpose. High strength steels exhibit a 
reduction of fatigue stress endurance during requalification and are 
therefore unsuitable for pressure testing. In general, the fatigue 
stress endurance limits increase with increasing ultimate tensile 
strength (the specifics are alloy dependent). At a certain ultimate 
tensile strength level, the fatigue stress endurance limit is 
drastically reduced with increasing tensile strength due to notch 
sensitivity. Increased notch sensitivity is a result of finer 
microstructural features that lead microstructural damage evolution 
(dislocation slips eventually accumulating to micro void coalescence 
and the initiation of a fatigue crack). Performing UE of high-strength 
seamless steel during requalification will detect fatigue cracks in 
cylinders/tubes while hydrostatic testing coupled with visual 
inspection has a significantly lower probability of detecting any 
fatigue cracks in cylinders/tubes. Therefore, we are continuing to 
require UE for UN cylinders with a tensile strength greater than or 
equal to 950 MPa.
(c) Acetylene Test Interval
    During review of the NPRM, we noted that the proposed revisions to 
Sec.  180.207(d)(3) for dissolved acetylene UN cylinders were not in 
alignment with the suggested test intervals in ISO 10462(E) or ISO 
10462 2013(E). Therefore, in the final rule, we will not make the 
proposed changes to Sec.  180.207(d)(3).
(4) Comments Related to Sec.  180.209
(a) Revisions to Requalification of Cylinders Table
    CTC and Independent Cylinder Training (ICT) submitted comments 
requesting we replace ``DOT 3'' with ``ICC 3'' and CTC and Bancroft 
Hinchey's comment to re-insert ``10'' for DOT 3A and 3AA and ``7'' for 
4B, 4BA, 4BW cylinders in Sec.  180.209(a) Table 1.
    PHMSA response. We agree with CTC, ICT, and Bancroft Hinchey that 
there are errors in the table in Sec.  180.209(a) Table 1. However, we 
proposed changes to Sec.  180.209(a) Table 1 in a different rulemaking 
\1\ and will take no action in this rulemaking to avoid potential for 
complication and confusion.
---------------------------------------------------------------------------

    \1\ See Response to an Industry Petition to Reduce Regulatory 
Burden for Cylinder Requalification Requirements, NPRM, 84 FR 38180 
(Aug. 6, 2019).
---------------------------------------------------------------------------

(b) Foreign Cylinders
    CTC and Wesley Scott submitted comments requesting that we change 
the requalification requirements for foreign cylinders in Sec.  180.209 
Table 1.
    PHMSA response. We do not agree with CTC and Wesley Scott's 
comments regarding test pressure of foreign cylinders in Sec.  
180.209(a) Table 1. Foreign-marked ISO cylinders are subject to the 
requirements of Sec.  180.207, and would not be subject to test at \5/
3\ of service pressure. Therefore, we will not change this requirement 
in Table 1.
(c) Footnote 1
    CTC, ICT, Hydro-Test Products and COSTHA's comments noted that we 
inadvertently deleted Footnote 1 of Table 1 in Sec.  180.209 and 
requested that we reinsert the footnote.
    PHMSA response. It was not our intent to change the requirements 
applicable to these small cylinders. In this final rule, we are not 
making any of the proposed changes to the table in Sec.  180.209 to 
avoid conflicts with other rulemaking efforts. In this final rule, we 
are not removing Footnote 1 of Table 1 in Sec.  180.209.
(d) Special Filling Limits (``+'' Mark) Relocation
    In P-1515, CTC requested that we move the requirements for special 
filling limits for DOT 3A, 3AX, 3AA, 3AAX and 3T cylinders found in 
Sec.  173.302a(b) to Sec.  180.209. We did not propose to take this 
action in the NPRM. CTC submitted a comment to the NPRM requesting that 
we reconsider our decision not to propose the change.
    PHMSA response. We disagree with CTC's request to move the current 
requirements in Sec.  173.302a(b) (``Special filling limits for DOT 3A, 
3AX, 3AA, 3AAX and 3T cylinders'') to Sec.  180.209. The requirements 
in Sec.  173.302a(b) deal with filling, and are properly placed in a 
filling section rather than a requalification section. Moving the 
requirements to a requalification section in part 180 would create 
unnecessary confusion. We additionally disagree with CTC's request to 
modify the language in Sec.  173.302a(b) to remove the table of steel 
types, average wall stress limitation, and maximum wall stress 
limitation. We acknowledge that this information can be found in CGA C-
5, which is incorporated by reference into the section, but we continue 
to see value in reproducing the table in the HMR for accessibility 
purposes. We did not propose this change in the NPRM, and we will not 
adopt this change in the final rule.
(e) 10-Year Requalification Condition Revisions (``Star'' Mark)
    CTC submitted a comment regarding the applicability of the ``star'' 
marking for 10-year requalification in Sec.  180.209(b), specifically 
requesting that we modify the change proposed in the NPRM to allow 
cylinders used in vehicles to continue to take the exception.
    PHMSA response. PHMSA is not changing the applicability of the 10-
year requalification to prohibit cylinders used in clusters, banks, 
groups, racks, or vehicles. If fillers are not removing these cylinders 
from the cluster, bank, group, rack, or vehicle, as stated by CTC in P-
1515, then they may not use the exception unless they have been issued 
a special permit. Changing the applicability of the exception is not an 
appropriate way to deal with this supposed compliance problem. We 
encourage cylinder users and fillers to re-familiarize themselves with 
the conditions for the 10-year requalification for DOT 3A and 3AA 
cylinders.

[[Page 85389]]

(f) 10-Year Requalification Expansion Limit
    ICT and Bancroft Hinchey also commented about their opposition to 
another part of this proposed change to Sec.  180.209(b), namely the 
new limit of 5 percent permanent expansion for these cylinders.
    PHMSA response. In this final rule, we are not modifying the 
applicability of the exception or creating a new permanent expansion 
limit. We are, however, modifying the exception by removing the 
``hammer test,'' as requested in P-1515 and proposed in the NPRM. The 
hammer test is outmoded and no longer provides relevant information 
regarding the continued strength of the cylinder. We may consider 
further modifying this exception in the future.
(5) Eddy Current Testing
    In the NPRM we proposed to change the applicability of the eddy 
current test, eddy current condemnation criteria, and eddy current 
record keeping requirements, as requested in P-1515. We do not believe 
the change and possible increase in cost is justified by data at this 
time. Therefore, in this final rule, we are not making any changes 
related to eddy current testing applicability, condemnation criteria, 
or recordkeeping.
(a) Test Applicability
    Currently, eddy current testing is required for 3AL cylinders made 
of aluminum alloy 6351-T6 in SCUBA, SCBA, or oxygen service. 3AL 6351-
T6 cylinders have been shown to be susceptible to sustained load 
cracking (SLC) in the neck and thread area of the cylinder. Eddy 
current testing combined with a detailed visual examination can 
identify SLC before it poses an immediate danger. We have required eddy 
current testing since the publication of HM-220F (71 FR 51122; 8/29/
2006). P-1515 requested that we change the applicability of the eddy 
current test to any DOT 3AL cylinder made of 6351-T6 alloy with a 
service pressure at or above 1,800 psig. We received one comment in 
support of this change from ICT. We did not discuss the proposed change 
in detail in the preamble to the NPRM, only stating, ``Specifically we 
plan to revise . . . the paragraph (m) requalification conditions for 
DOT 3AL cylinders made of 6351-T6 aluminum alloy.'' We are concerned 
that the change from a gas service-based testing applicability to a 
pressure-based testing applicability may significantly increase the 
number of cylinders subject to eddy current testing, without adequate 
notice to the regulated community or safety justification.
    Since the imposition of the eddy current test requirement in 2006, 
we are not aware of any catastrophic failures of DOT 3AL cylinders 
involving sustained load cracking. In this final rule, we are not 
making the proposed change to eddy current test applicability. We 
welcome further petitions on the matter, but we do not believe the 
change and possible increase in cost is justified by data at this time.
(b) Condemnation Criteria
    Similarly, we are not making any change to eddy current 
condemnation criteria. The current criteria in the HMR have proved 
successful in identifying cylinders prone to sustained load cracking, 
facilitating their removal from service before cracks can cause 
catastrophic failure. We may consider revising the condemnation 
criteria in a future rulemaking, but will make no change to eddy 
current condemnation criteria at this time.
(c) Record-Keeping
    In the NPRM, we proposed changes to eddy current recordkeeping 
requirements. We proposed to move eddy current recordkeeping 
requirements currently found in appendix C to part 180 to new Sec.  
180.215(b)(5). We received a comment from ICT opposed to the relocation 
of requirements from appendix C to part 180 into Sec.  180.215(b)(5). 
We agree with ICT and are not making the proposed change to relocate 
requirements out of appendix C to part 180 at this time. Eddy current 
testers are familiar with the requirements found in appendix C to part 
180 and moving the requirements to a new section would create 
unnecessary confusion. We may review eddy current recordkeeping 
requirements in a future rulemaking.
(6) Comments Related to Sec.  180.209(j)
(a) Incorporation by Reference of CGA C-1
    CTC commented on the proposed language in Sec.  180.209(j) and 
stated their opinion that the language was unnecessarily confusing and 
redundant following the incorporation of CGA C-1.
    PHMSA response. We agree with CTC's comment that there are 
redundant instructions in Sec.  180.209(j), and the requirements could 
be simplified by referring to the test procedures in CGA C-1. 
Additionally, COSTHA noted an error in the structure of Sec.  
180.209(j), where it appeared the proposed paragraphs (j)(2) and (3) 
overlapped in applicability and contradicted each other. We appreciate 
this comment, and have re-structured Sec.  180.209(j) to make clear 
that paragraph (j)(1)(i) applies to smaller 4B, 4BA, 4B240ET, or 4BW 
cylinders, paragraph (j)(1)(ii) to larger 4B, 4BA, 4B240ET, or 4BW 
cylinders, and (j)(2) to 3A, 3AA, or 3AL cylinders.
(b) Increased Pressure for Repeat Tests
    ICT commented on our proposed requirement to increase the pressure 
by 10 percent for a repeated proof pressure test for fire 
extinguishers, noting this was not in accordance with CGA C-1 
requirements.
    PHMSA response. We agree, and are removing this provision and 
replacing it with instructions to conduct the proof pressure test in 
accordance with CGA C-1.
(c) 4E Cylinders
    While reviewing Sec.  180.209(j), we noted erroneous references to 
DOT 4E cylinder condemnation criteria. DOT 4E cylinders are generally 
not eligible to be transported or requalified as fire extinguishers, so 
we have removed the reference to 4E condemnation criteria from Sec.  
180.209(j).
    In the final rule, we are revising Sec.  180.209(j) as discussed 
above to simplify and clarify the requirements for the requalification 
of specification fire extinguishers.
(7) Comments Related to Sec.  180.212
    Bancroft Hinchey commented in support of the proposed requirement 
in Sec.  180.212(a)(3) to require ultrasonic testing (UT) after a 
repair facility conducts a repair involving grinding.
    PHMSA response. In this final rule, we are adopting this 
requirement as proposed.
(8) Comments Related to Sec.  180.213
(a) Requalification Label Embedded in Epoxy
    Numerous commenters, including NPGA, Amerigas, Firehouse Hydro 
Sales and Service, Joshua Blake, Hydro-Test Products, and Scuba Do 
noted that we made an error in Sec.  180.213(c) for requalification 
marking methods by removing the authorization for a label embedded in 
epoxy.
    PHMSA response. The commenters are correct that we inadvertently 
did not include the provision allowing for applying a label embedded in 
epoxy. This was not our intent as part of the HM-234 NPRM. Therefore, 
in this final rule we are including the label in epoxy marking method 
in Sec.  180.213(c) as is currently allowed under the HMR. We 
appreciate the commenters' attentiveness in addressing this 
unintentional omission in the NPRM.

[[Page 85390]]

(b) Requalification Marking Location
    Independent Cylinder Training (ICT), Amerigas, and NPGA oppose the 
proposed requirement in Sec.  180.213(c)(1)(i) that would require 
requalification marks be placed in a specific location adjacent to the 
original manufacturing markings. ICT, Amerigas, and NPGA state that 
this requirement is too restrictive, and in certain cases impossible to 
meet due to the size and type of cylinders involved. Bancroft Hinchey 
supports a requirement to ``lay out requalification markings neatly and 
consistently.''
    PHMSA response. We agree with the comments submitted by ICT, 
Amerigas, and NPGA. While we would have liked to provide a consistent 
location for requalification markings for shippers and fillers, we 
recognize the diversity of cylinder types and sizes makes this effort 
difficult. Therefore, in this final rule we are not adopting the change 
to Sec.  180.213(c) that was proposed in the NPRM. Requalification 
markings must be applied in a legible and durable manner and may be 
placed on any portion of the upper end of the cylinder excluding the 
sidewall. We welcome petitions on this requirement for possible 
inclusion in a future rulemaking.
(c) Requalification Marking Depth
    Bancroft Hinchey commented that Sec.  180.213(c) should be modified 
to provide guidance on requalification marking depth when the cylinder 
specification does not provide any information on accepting marking 
depth.
    PHMSA response. While PHMSA agrees that cylinder requalifiers 
should not mark cylinders to a depth greater than the original 
manufacturer's markings, we do not agree with Bancroft Hinchey's 
comment to modify Sec.  180.213(c). PHMSA believes that including the 
phrase ``or the original manufacturer's markings'' to Sec.  180.213(c) 
will increase confusion among cylinder requalifiers.
(9) Comments Related to Sec.  180.215
(a) Use of Symbols for Cylinder Dimension
    Bancroft Hinchey requested clarification of the revision to Sec.  
180.215 to permit use of symbols for actual dimensions.
    PHMSA response. The use of a symbol in place of the written 
dimensions of the cylinder is permitted by Sec.  180.215(b) as long as 
the symbols on the reference chart available at the requalifier's 
facility are accurate for the actual measured dimensions of each 
cylinder requalified. It is PHMSA's understanding that some cylinder 
requalifiers maintain reference charts with symbols cross-referenced to 
the actual measured dimensions of common cylinder models. As long as 
the facility has an accurate reference document that cross-references 
the symbol entered on the requalification record with the actual 
measured dimensions of the cylinder requalified, they may use that 
symbol to meet the requirement to enter the actual dimensions of a 
cylinder on the requalification record. This will increase flexibility 
and reduce burdens for requalifiers without compromising safety.
(b) Gas Service and Year of Manufacture
    Hydro-Test Products commented on the proposed change to cylinder 
requalification recordkeeping requirements. They noted that in the NPRM 
we did not discuss the additional requirement to record the cylinder's 
year of manufacture or gas service in Sec.  180.215(b)(2). Hydro-Test 
Products is opposed to the proposed change to cylinder requalification 
recordkeeping requirements and believes it would impose an undue burden 
on cylinder requalifiers.
    PHMSA response. We disagree with Hydro-Test Products' comment. The 
requirement for cylinder requalifiers to keep a record of the 
cylinder's date of manufacture and gas service is useful for several 
reasons. The eligibility for the ``star'' mark in Sec.  180.209(b), 
allowing a 10-year requalification period instead of 5 years, depends 
on the year of manufacture and gas service, as does the ``+'' mark for 
10 percent overfilling in Sec.  173.302a(b). The applicability of the 
option to requalify a cylinder via external visual inspection in Sec.  
180.209(g) is also dependent on the particular gas service in which the 
cylinder is used. The year of manufacture is also helpful in 
determining whether a 3AL cylinder was constructed from 6351-T6 
aluminum alloy, and therefore subject to eddy current examination. Use 
of 6351-T6 aluminum alloy in DOT 3AL cylinders was discontinued in 
1990. We believe that the addition of these two pieces of information 
to cylinder requalification records creates only a minimal reporting 
burden on the regulated community while aligning recordkeeping 
requirements with operational practice. See further discussion in 
Section VIII.G in this rulemaking document regarding the information 
collection burden of this requirement. In this final rule, we are 
adopting the changes as proposed, and modifying Sec.  180.215(b)(2) to 
require cylinder requalifiers to record the year of manufacture and gas 
service of each cylinder they requalify.
(10) Reclaimed Refrigerant Gas
    Section 180.209(e) authorizes proof pressure testing for DOT 4-
series cylinders in non-corrosive gas service. In the NPRM we proposed 
to add the following sentences to this paragraph: ``However, a cylinder 
used for reclaiming, recycling, or recovering refrigerant gases must be 
requalified by volumetric expansion testing every 5 years. Reclaimed, 
recycled, or recovered refrigerant gases are considered to be corrosive 
due to contamination.'' In this final rule, we are not adding these 
sentences to Sec.  180.209(e). Although we believe that cylinders used 
for reclaimed refrigerant gases are generally not eligible for the 
exception in Sec.  180.209(e) because of the contaminants encountered 
in this service, we are uncertain whether this is always the case. 
Therefore, PHMSA has decided that the most practical regulatory 
alternative at this time is to leave the Sec.  180.209(e) exception 
allowing a 10-year testing interval for DOT 4-series cylinders used in 
non-corrosive gas service unchanged. As provided in Sec.  173.22, it is 
the shipper's responsibility to classify a hazardous material properly.
(11) RIN Markings for Foreign Cylinders
    In the HMR, foreign cylinders not manufactured to a DOT, UN, TC, 
CTC, BTC or CRC specification may be filled and transported for export 
or for use on board a vessel in accordance with Sec.  171.23(a)(5) 
(note that this reference was originally Sec.  171.23(a)(4), and has 
changed to Sec.  171.23(a)(5) after publication of final rule HM-219C). 
Requalification for these cylinders is discussed in Sec.  180.209(l), 
which prohibits the marking of the cylinder with a requalifier's RIN, 
instead requiring only the month and year of requalification. In the 
NPRM, we proposed to require a RIN marking for these foreign cylinders, 
along with the symbol ``EX,'' to reduce confusion among fillers and 
clarify that these foreign cylinders had been requalified in accordance 
with part 180, subpart C. We received no comments on this proposal. In 
this final rule, we will adopt this requirement. We believe that the 
symbol ``EX'' in association with the RIN provides necessary 
information to inspectors and users that these cylinders are limited to 
export or vessel service in accordance with Sec.  171.23(a)(5). The 
inclusion of a RIN marking, which signifies compliance with part 180 
subpart C, will increase clarity for fillers

[[Page 85391]]

that the cylinders have been properly requalified.

P-1521

    CGA submitted P-1521 requesting that PHMSA modify a provision in 
Sec.  172.400a(a)(1) (specifically Sec.  172.400a(a)(1)(i) at the time 
the petition was submitted) to remove the limitation that only allows 
the use of the neckring markings if a cylinder is not overpacked. The 
petition would still require the overpack to display the labels in 
conformance with 49 CFR part 172, subpart E. In the NPRM, PHMSA 
proposed to revise Sec.  172.400a(a)(1)(i) to remove the limitation 
that would only allow the use of the neckring markings if the cylinders 
are not overpacked, as proposed in P-1521. National Association of Fire 
Equipment Distributors (NAFED) and Worthington Cylinder submitted 
comments supporting this change.
    On January 21, 2016, PHMSA published HM-233F (81 FR 3635), which 
adopted numerous special permits into the HMR. In particular, we 
adopted DOT SP 14251, which authorizes the transportation of overpacked 
cylinders marked in accordance with CGA publication C-7 provided the 
overpacks are properly labeled. Therefore, the intent of P-1521 has 
already been accomplished. We appreciate CGA's petition and COSTHA's 
comment highlighting that HM-233F already addressed this issue.

P-1538

    On behalf of Jetboil, Inc., The Wicks Group submitted P-1538 
requesting that PHMSA revise Sec.  173.306(a)(1) to permit camping 
stove cylinders containing liquefied petroleum gas (LPG) in amounts 
less than 4 ounces but in a container exceeding 4 fluid ounce capacity 
to be shipped as consumer commodity (ORM-D). Historically, PHMSA has 
limited the amount of compressed gas in limited quantity packagings to 
reduce the opportunity and speed of the gaseous product's reaction to 
an activating event, having found that including non-gaseous materials 
in the same container with the gas--such as foodstuffs, soap, etc.--
slowed this reaction. The Interstate Commerce Commission first adopted 
the provision for Sec.  173.306(a)(1) (previously Sec.  73.306(a)(1)) 
in a final rule published July 1, 1966 (31 FR 9067). The provision 
provided an ``exemption'' (i.e., an exception) from regulations for 
shipping of compressed gases ``when in containers of not more than 4 
fluid ounce water capacity.'' Thus, historically, the provision applies 
to the capacity of the container and not to the quantity of its 
contents. This is consistent with design requirements for the capacity 
of packagings found in part 178 that includes a specification for the 
water capacity of the packaging (e.g., Specification 3A and 3AX 
seamless steel cylinders in Sec.  178.36); however, the publication of 
a final rule on April 15, 1976 (41 FR 15972) inadvertently dropped the 
term ``water'' from paragraph (a)(1) regardless of there having been no 
express discussion of the intent to do so or to change the size 
standard from the originally adopted water capacity to the quantity of 
the contents.
    Furthermore, the definition ``maximum capacity'' was introduced as 
part of a harmonization effort with international regulations and 
standards in a final rule published December 21, 1990 (55 FR 52402) for 
consistency with use of terminology internationally for UN performance 
oriented packaging. See the part 178, subpart L non-bulk performance 
oriented packaging sections. Therefore, based on the historical context 
of capacity as its use in Sec.  173.306(a)(1) to mean water capacity 
and the adoption of the term ``maximum capacity'' in association with 
the adoption of UN performance oriented packaging, PHMSA did not 
propose to adopt the petition. We received one comment on this topic. 
Worthington Cylinder submitted a comment supporting PHMSA's proposal to 
deny the petition and not amend Sec.  173.306(a)(1). Therefore, as 
reasoned in the NPRM, we are not adopting P-1538 in this final rule.

P-1539

    Matheson-TriGas submitted P-1539 requesting that PHMSA revise Sec.  
180.209, which prescribes requirements for requalifying cylinders. 
Paragraph (a) of Sec.  180.209 requires each DOT-specification cylinder 
listed in ``table 1 of this paragraph'' to be requalified and marked in 
conformance with requirements specified in Sec.  180.209. The 
petitioner requested that PHMSA extend the 10-year retest period 
prescribed in this table for DOT 3A, 3AA, and 3AL specification 
cylinders in Division 2.2 (non-flammable) gas service to once every 15 
years. Matheson-TriGas also requested in its petition that PHMSA extend 
the 5-year retest period prescribed in this table for DOT 3A, 3AA, and 
3AL specification cylinders in Division 2.1 (flammable) gas service to 
once every 10 years. The petitioner states: ``Historically over 99.4 
percent of cylinders in the above[-mentioned] services that were 
[subjected] to the water jacket test pass the test,'' and ``it is more 
likely . . . the cylinder failed the external or internal visual [test] 
rather than failing the water jacket test.''
    Matheson-TriGas notes PHMSA's statement from an earlier rulemaking 
(HM-220; 63 FR 58460) regarding the history of the plus rating for 
steel cylinders resulting from the steel shortage of World War II, 
which resulted in changes ``that benefitted the industry with no 
compromise of public safety down to this day.'' Matheson-TriGas 
extrapolates that we face similar metal shortage challenges in today's 
economy.
    Based on concerns about increasing the risk of cylinder failure by 
lengthening the timeframe between periodic qualifications, PHMSA did 
not propose to revise the 10-year requalification period for DOT 3A, 
3AA, and 3AL specification cylinders in Division 2.2 (non-flammable) 
gas service to once every 15 years, nor to revise the 5-year 
requalification period for DOT 3A, 3AA, and 3AL specification cylinders 
in Division 2.1 (flammable) gas service to once every 10 years.
    We received three comments on this topic. Bancroft Hinchey, NAFED, 
and CGA all supported our decision not to adopt the petition. 
Therefore, as reasoned in the NPRM, we are not adopting P-1539.

P-1540

    CGA submitted P-1540 requesting that PHMSA require newly 
manufactured DOT 4B, 4BA, 4BW, and 4E cylinders to be marked with the 
mass weight or tare weight, and the water capacity. As specified in 
Sec.  178.35(f), the HMR require DOT-specification cylinders to be 
permanently marked with specific information, including the DOT-
specification, the service pressure, a serial number, an inspector's 
mark, and the date manufacturing tests were completed. These marks 
provide vital information to fillers and uniquely identify the 
cylinder.
    Certain DOT 4-series specification cylinders contain liquefied 
gases filled by weight, so the tare weight (the weight of the empty 
cylinder and appurtenances) or the mass weight (the weight of the empty 
cylinder), and the water capacity must be known by the filler to fill 
the cylinder properly. This information is essential for cylinders 
filled by weight, as cylinders overfilled with a liquefied gas can 
become liquid full as the ambient temperature increases. If 
temperatures continue to rise, pressure in the overfilled cylinder will 
rise disproportionately, potentially leading to leakage or a violent 
rupture of the cylinder after only a small rise in temperature. Despite 
these risks, the HMR do not require tare weight, mass

[[Page 85392]]

weight, or water capacity markings on DOT-specification cylinders.
    To address this, the CGA petitioned PHMSA to require tare weight or 
mass weight, and water capacity to be marked on newly constructed DOT 
4B, 4BA, 4BW, and 4E specification cylinders. The petition also 
requests that PHMSA provide guidance on the accuracy of these markings 
and define the party responsible for applying them. In its petition, 
CGA notes that PHMSA has incorporated by reference the National Fire 
Protection Association's ``58-Liquefied Petroleum Gas Code, 2001 
edition'' (NFPA 58), which requires cylinders used for liquefied 
petroleum gases to be marked with the tare weight and water capacity; 
\2\ however, as stated in the petition, NFPA 58 gives no guidance as to 
the accuracy of these markings or the party required to provide them. 
The CGA states that this lack of guidance can lead to the overfilling 
of a cylinder and the potential for unsafe conditions.
---------------------------------------------------------------------------

    \2\ Note that NFPA 58 was not incorporated by reference for 
marking purposes but for purposes of equipping storage tanks 
containing LPG or propane with safety devices. See Sec.  173.315(j).
---------------------------------------------------------------------------

    While DOT 4B, 4BA, 4BW, and 4E cylinders are often used to 
transport liquefied compressed gas, we noted in the ANPRM that these 
are not the only cylinder types used for liquefied compressed gas 
transport. PHMSA understands that many in the compressed gas industry, 
especially the liquefied petroleum gas industry, already request 
manufacturers to mark cylinders with the tare weight or water capacity 
as an added safety measure. Based on this assumption, PHMSA estimates 
the impact on the liquefied compressed gas industry will be minimal, as 
many in the industry are already applying these markings voluntarily.
    PHMSA requested comments and supporting data regarding the 
increased safety benefits and the economic impact of this proposal. 
With regards to the cost associated with this modification, in the 
ANPRM, PHMSA asked the following specific questions:
    <bullet> What is the average total cost per cylinder to complete 
these markings (i.e., is an estimated cost of $0.10 per character for 
new markings accurate)?
    <bullet> What is the estimated quantity of newly manufactured 4B, 
4BA, 4BW and 4E cylinders each year? Furthermore, how many of these 
cylinders already display tare weight and water capacity markings in 
compliance with NFPA 58 or other codes?
    <bullet> How many manufacturers of the cylinders mentioned above 
are considered small businesses by the SBA?
    PHMSA sought to identify: (1) The frequency of which the mass 
weight or tare weight, and water capacity markings are already 
permissively applied to cylinders, (2) the costs associated with 
applying these marks, (3) the safety benefits associated with the 
additional markings, and (4) the alternate methods or safeguards 
against overfilling of cylinders currently being implemented.
    Air Products and Chemicals submitted a comment to the ANPRM that 
supported the petition but they did not discuss the basis for their 
support. CGA submitted a comment to the ANPRM supporting the inclusions 
of tare weight, mass weight, and water capacity requirements on newly 
constructed DOT 4B, 4BA, 4BW, and 4E specification cylinders at the 
time of manufacture but did not support--and ``strongly disagrees'' 
with--PHMSA's consideration of modifying Sec.  178.35 to require all 
DOT-specification cylinders suitable for the transport of liquefied 
gases to be marked with the cylinder's tare weight and water capacity. 
The CGA also believed that the HMR must further clarify that no 
cylinder may be filled with a liquefied gas unless a mass or tare 
weight is marked on the cylinder, providing the following 
justification:
    <bullet> At the time of manufacture, the manufacturer would not 
know whether the DOT 3-series cylinders are, or are not, to be used in 
a liquefied gas service.
    <bullet> Marking all cylinders, as suggested by DOT, would include 
every cylinder manufactured in conformance with the specifications set 
forth in the HMR, which would therefore require cylinders that have 
been designed and manufactured for a specific permanent gas application 
to be marked for tare weight and water capacity just because the 
cylinder could be used (at some time) for liquefiable gas.
    <bullet> There would be instances on small DOT 3-series cylinders 
where the additional marking would not fit onto the dome of the 
cylinder.
    <bullet> The economic impact estimated for marking all cylinders is 
significantly greater than the estimates submitted by PHMSA.

Manchester Tank submitted a comment to the ANPRM expressing concern 
that numerous variations in stamped weights could cause confusion in 
the field among fillers. They stated that adding mass weight stamping 
to a cylinder that already has tare weight stamped could lead to 
incorrect filling if the wrong figure is used. They asked PHMSA to 
clarify who would have responsibility to assign the duty to mark tare 
weight to the valve installer and indicated that there are many 
cylinders that are not valved by the manufacturer, and further declared 
that those cylinders can be marked correctly with mass weight--but not 
with tare weight, since the weight of the appurtenance may not be known 
to the manufacturer of the vessel. In addition, Manchester Tank notes 
that available space for stamping is limited on some vessels and 
increased stamping will not allow significant space for retest marking 
information.
    In the NPRM, PHMSA proposed to revise Sec.  178.35(f) to require 
that tare weight or mass weight, and water capacity be marked on all 
DOT 4B, 4BA, 4BW, and 4E specification cylinders.
    We received nine comments to the NPRM related to this issue. Fike 
Corporation, Janus Fire Systems, Amerex, NAFED, and FSSA submitted 
comments opposing the requirement to mark all DOT 4B, 4BA, 4BW, and 4E 
cylinders with tare weight or mass weight, and water capacity. Bancroft 
Hinchey, Kidde-Fenwal, Worthington Cylinder and CGA submitted comments 
generally supportive of the requirement, but requested certain 
modifications. Bancroft Hinchey requested that Sec.  180.215 be 
modified to require tare weight be added to a 4-series cylinder if it 
changes service to liquefied gas. Kidde-Fenwal requested that the 
marking requirements only apply to cylinders filled with liquefied gas, 
and not 4-series cylinders used for other services, such as fire 
extinguishers containing an extinguishing agent and charged with a non-
liquefied gas. Worthington Cylinder requested that the requirement only 
apply to cylinders filled with liquefied gas and that the regulations 
require specific acronyms for mass weight, tare weight, and water 
capacity to reduce confusion. CGA requested a minor change to the 
wording in Sec.  178.35(f)(7)(iii) to ensure proper tolerance 
requirements as requested in P-1540.
    PHMSA response. We agree with the commenters that there is no value 
in requiring the tare weight or mass weight, and water capacity 
markings for 4-series cylinders that are not used for liquefied 
compressed gases, as these materials are not filled by weight. However, 
we do not agree that relying on voluntary industry standards that may 
require the tare weight or water capacity on a cylinder label is 
adequate to alleviate our safety concerns regarding proper filling of 
liquefied compressed gases. We do not believe that NFPA 58 is 
universally followed in the cylinder industry. Additionally, the NFPA 
58 does not assign a particular

[[Page 85393]]

party to apply the marks, or any accuracy requirements for the 
measurements. Therefore, the creation of a Federal standard for tare 
weight/mass weight and water capacity markings on DOT 4B, 4BA, 4BW and 
4E cylinders used for only liquefied compressed gases provides a higher 
level of safety and oversight than the NFPA 58 standard while limiting 
burdens to the cylinder industry.
    PHMSA expects this marking requirement to play a role in preventing 
overfilling incidents, which can result in explosions and fatalities. 
For example, in 2014, an overfilled propane cylinder ruptured, 
exploded, and fatally injured two people and injured others in 
Philadelphia.\3\ Specifically, a cylinder filler, using the tare/mass 
weight and water capacity markings to guide their filling practice, is 
expected to be significantly less likely to overfill a cylinder. Adding 
tare weight or mass weight, and water capacity markings is expected to 
improve safety for cylinder fillers, transporters, and the general 
public by decreasing the incidence of overfilled cylinders entering 
transportation. Cylinders filled with liquefied gases must be filled by 
weight (see Sec.  173.304a(c)). The filler must determine the weight of 
the cylinder in order to fill the cylinder with the proper amount of 
liquefied gas. The most direct way to ensure that the filler knows the 
weight of the cylinder being filled is to require that the cylinder's 
weight be marked on the cylinder itself.
---------------------------------------------------------------------------

    \3\ This incident resulted in a Federal judge ordering the 
company who filled the cylinder to pay a $1 million criminal. In 
addition, the company entered into an historic civil settlement, 
agreeing to pay victims and the family of those fatally injured $160 
million, plus an additional confidential sum. See Moselle, Aaron. U-
Haul fined $1 million after fatal food truck explosion in North 
Philly. May 7, 2019. WHHY.org. Available at: https://whyy.org/articles/uhaul-fined-1-million-after-fatal-food-truck-explosion-in-north-philly/.
---------------------------------------------------------------------------

    By requiring these markings, PHMSA will help to eliminate confusion 
and guesswork while providing a potentially quicker and more efficient 
way to determine the cylinder weight than relying solely on reference 
materials listing cylinder weights. Cylinder fillers may not always 
have easy access to cylinder tare/mass weight and water capacity 
reference materials; the materials may become outdated; or the 
reference materials that are available may have been created by a 
cylinder manufacturer other than the manufacturer of the cylinder being 
filled.
    In addition, providing the markings may prevent a cylinder filler 
from being required to weigh the purportedly empty cylinder to 
determine the tare weight, removing errors due to residue material that 
would overstate the tare weight when weighed manually, and also 
reducing burden. Further, PHMSA believes that the addition of these 
markings could reduce the occurrence of non-compliant filling methods, 
such as informally relying on auditory cues (e.g., shaking the 
cylinder).
    Increasing availability of cylinder weight and capacity information 
on the cylinder itself will decrease the chances of operator error 
leading to overfilled cylinders. Therefore, in this final rule, we are 
modifying the proposed requirement from the NPRM that DOT 4B, 4BA, 4BW 
and 4E cylinders used for only liquefied compressed gases must be 
marked with tare weight or mass weight, and water capacity. The details 
are discussed in the VII. Section-by-Section Review. We are also 
adopting the upper and lower tolerances for the tare weight/mass weight 
marking as proposed by CGA. We agree that additional markings on a 
cylinder may be a source of confusion, but we believe that this can be 
mitigated by using standardizing abbreviations. Accordingly, in this 
final rule we are requiring that tare weight be abbreviated ``TW'', 
mass weight ``MW'', and water capacity ``WC.'' The responsibility for 
meeting this requirement is placed on the owner of the cylinder, as 
they are best positioned to understand the eventual use of the cylinder 
at the time of manufacture. We stress that while cylinder markings are 
important to ensure the safe filling of liquefied compressed gas, they 
do not take the place of adequate personnel training, procedures to 
ensure proper filling, and continued requalification and maintenance of 
cylinders in preventing incidents.
    In accordance with Sec.  173.304a(c), liquefied gases must be 
filled by weight, or when the gas is lower in pressure than required 
for liquefaction, a pressure-temperature chart for the specific gas may 
be used to ensure that the service pressure at 55 [deg]C (131 [deg]F) 
will not exceed \5/4\ of the service pressure at 21 [deg]C (70 [deg]F). 
An accurate scale must be used to check the weight of liquefied gas 
filled in the cylinder. These requirements apply to all types of 
cylinders, not only the 4B, 4BA, 4BW and 4E cylinders whose marking 
requirements we are amending in this final rule. We believe that by 
requiring TW, MW and WC markings for these cylinders which are most 
commonly used for liquefied gases, we will create the greatest safety 
benefit while minimizing costs to the regulated community.
    We note that COSTHA submitted a comment that we left the word 
``no'' out of the phrase ``[no] upper [tolerance]'' in the proposed 
Sec.  178.35(f)(7)(iii) for the criteria for the water capacity marking 
for a cylinder exceeding 25 pounds. COSTHA is correct in its 
understanding. This was an inadvertent omission and we are correcting 
Sec.  178.35(f)(8)(iii) (please note that the original regulatory text 
proposed in Sec.  178.35(f)(7) has been redesignated as paragraph 
(f)(8) due to changes made to the HMR since the publication of the HM-
234 NPRM) such that it reads ``with a tolerance of minus 0.5 percent 
and no upper tolerance'' in this final rule.
    Lastly, we are making an editorial change in the final rule and 
deleting the metric units from Sec.  178.35(f)(8) to increase clarity 
and decrease confusion for manufacturers, fillers, and users of these 
cylinders.

P-1546

    GSI Training Services submitted P-1546 requesting that PHMSA allow 
cylinders that form a component of fire suppression systems to use the 
proper shipping name ``Fire extinguishers'' when offered for 
transportation. The Hazardous Materials Table (HMT) in Sec.  172.101 
provides a shipping description for cylinders used as fire 
extinguishers (i.e., ``UN1044, Fire extinguishers, 2.2'') and 
references Sec.  173.309 for exceptions and non-bulk packaging 
requirements. Fire extinguishers charged with a limited quantity of 
compressed gas are excepted from labeling, placarding, and shipping 
paper requirements under certain conditions if the cylinder is packaged 
and offered for transportation in conformance with Sec.  173.309.\4\ 
Additionally, fire extinguishers filled in conformance with the 
requirements of Sec.  173.309 may use non-specification cylinders 
(i.e., cylinders not manufactured to specifications in part 178). Part 
180 also provides special requirements for cylinders used as fire 
extinguishers (e.g., Sec.  180.209(j) includes different 
requalification intervals).
---------------------------------------------------------------------------

    \4\ Note that the format of Sec.  173.309 was changed under a 
final rule published January 7, 2013 (HM-215K; 78 FR 1101) such that 
the exceptions for limited quantities has been relocated to 
paragraph (d) of Sec.  173.309.
---------------------------------------------------------------------------

    PHMSA has written several letters of interpretation regarding the 
applicability of Sec.  173.309 to fire extinguishers. Notably on March 
9, 2005, PHMSA wrote a letter of interpretation (Reference No. 04-0202) 
to Safecraft Safety Equipment regarding non-specification stainless 
steel cylinders used as a component in a fire suppression system for 
installation in

[[Page 85394]]

vehicles and stated that the cylinders used in the fire suppression 
system appeared to meet the requirements of Sec.  173.309. PHMSA issued 
another letter of interpretation (Reference No. 06-0101) on May 30, 
2008, to Buckeye Fire Equipment stating that the company could not use 
the shipping name ``Fire extinguishers'' for their cylinders, which 
served as a component of a kitchen fire suppression system, and must 
use the proper shipping name that best describes the material contained 
in the cylinder because these cylinders were not equipped to function 
as fire extinguishers. This latter clarification effectively required 
cylinders that are part of a fixed fire suppression system to meet an 
appropriate DOT-specification.
    In response to Reference No. 06-0101, GSI Training Services 
submitted a petition for rulemaking requesting PHMSA to allow cylinders 
that form a component of fire suppression systems to use the proper 
shipping name ``Fire extinguishers'' when offered for transportation, 
stating that: (1) At least one company manufactured over 39,000 non-
specification cylinders for use in fire suppression systems based on 
the information provided in the March 9, 2005 letter; and (2) the May 
30, 2008 clarification effectively placed this company out of 
compliance. GSI Training Services further suggested that cylinders 
comprising a component of a fixed fire suppression system will provide 
an equal or greater level of safety than portable fire extinguishers 
since cylinders in fire suppression systems are typically installed in 
buildings where they are protected from damage and not handled on a 
regular basis.
    In the NPRM, PHMSA proposed to revise the Sec.  173.309 
introductory text to include ``fire extinguishers for installation as 
part of a fire suppression system'' as a fire extinguisher type 
authorized for transport in accordance with authorized packaging 
requirements as assigned to the HMT entry for fire extinguishers.
    Comments. Guardian Services, Inc., Janus Fire Systems, Amerex, 
Worthington Cylinder and the Fire Suppression Systems Association 
commented in support of this proposal. Kidde-Fenwal commented in 
support of the proposal, but also stated that ``not all cylinders 
intended for use as a component of a fire suppression system should 
utilize the `Fire extinguisher, UN 1044 designation' as suppression 
agents with their own HMT designation (example, UN 3296) should 
continue to be identified as such.'' That is, those fire suppression 
agents listed by name should continue to be described and packaged as 
provided in the HMT rather that as UN1044, Fire extinguishers.
    The National Association of Fire Equipment Distributors (NAFED) 
commented in opposition to the proposal, specifically noting its 
concerns with allowing high pressure, inert gas cylinders used in 
``engineered-type'' fire suppression systems to be transported and 
requalified as ``UN1044, Fire extinguishers.'' The ``engineered-type'' 
fire suppression systems that NAFED described are large fire 
suppression systems used in industrial settings that may consist of a 
vessel that contains an extinguishing agent and separate compressed gas 
``charging'' cylinders that provide the pressure to inject the agent 
into the system upon activation. Other engineered systems may consist 
of a fire extinguishing agent pressurized with an inert gas, or consist 
of cylinders that contain only an inert gas.
    PHMSA response. We disagree with Kidde-Fenwal. The classification 
of ``UN1044, Fire extinguisher'' is based on the intended use of the 
cylinder, and should not necessarily exclude gases listed by name in 
the Sec.  172.101 HMT if the conditions of Sec.  173.309 are met. 
However, we agree with NAFED's concerns regarding ``charging'' 
cylinders transported separately from fire suppression systems. Our 
intent in the NPRM was to propose allowing fire extinguishers that are 
charged with a compressed gas and an extinguishing agent and that are 
intended for installation into fire suppression systems to be described 
as ``UN1044, Fire extinguishers.'' We did not intend to allow cylinders 
charged with an inert gas and used only to pressurize a fire 
suppression system to be described as ``UN1044, Fire extinguishers'' 
when offered for transportation separately from the suppression system. 
These ``charging'' cylinders must be described based on the compressed 
gas they contain, for example ``UN1066, Nitrogen.'' or ``UN1006, 
Argon.''
    In this final rule, we are adopting the proposed change to Sec.  
173.309, and further clarifying our meaning. A fire extinguisher 
charged with a compressed gas and an extinguishing agent that is 
intended for installation into a fire suppression system may be 
described as ``UN1044, Fire extinguisher'' if it meets the conditions 
of Sec.  173.309. A fire extinguisher charged with a compressed gas 
that is the sole extinguishing agent in the system that is intended for 
installation into a fire suppression system may also be described as 
``UN1044, Fire extinguisher'' if it meets the conditions of Sec.  
173.309. A cylinder charged with a gas and used only to pressurize or 
expel an extinguishing agent as part of a fire suppression system may 
not be described as ``UN1044, Fire extinguisher'' for purposes of the 
HMR.
    Section 173.309(a) requires the use of a DOT-specification 
cylinder, as is generally required for a compressed gas, and further 
requires the use of dry gas and extinguishing agents that are 
commercially free from corroding components. The safety and performance 
of DOT specification cylinders filled with dry gas and an extinguishing 
agent commercially free of corroding components and requalified as 
provided in Sec.  180.209(j) is expected to be the same for manual use 
(i.e., handheld) and for use in fixed fire suppression system service. 
Section 173.309(b) requires the use of Specification 2P or 2Q non-
refillable inside metal containers, filled with a non-corrosive 
extinguishing agent. DOT 2P and 2Q containers are very limited in size 
and service pressure by their design specification in Sec. Sec.  178.33 
and 178.33a, and therefore would have limited utility for a fixed fire 
suppression system. Finally, with respect to authorizing use of non-DOT 
specification cylinders, we believe the requirements in Sec.  
173.309(c) provide for the safe transportation of compressed or 
liquefied gas regardless of whether the cylinder is equipped for manual 
use as a fire extinguisher (i.e., handheld) or for use as a fire-
extinguishing component of a fire suppression system.
    Section 173.309(c) allows the use of non-specification cylinders 
filled with a non-corrosive extinguishing agent as fire extinguishers. 
These non-specification cylinders are limited in size to 1,100 cubic 
inches, or 55 cubic inches if they contain any liquefied compressed 
gas. The cylinders must be pressure tested to three times (3x) their 
charged pressure prior to initial shipment, and must be designed with a 
burst pressure six times (6x) their charged pressure. This exceeds the 
burst pressure ratio of DOT-specification cylinders authorized under 
Sec.  173.309(a). These non-DOT specification cylinders must 
additionally be periodically requalified in accordance with the 
requirements of the Department of Labor's Occupational Safety and 
Health Administration regulations pertaining to ``portable fire 
extinguishers'', 29 CFR 1910.157. The combination of size restriction, 
higher than normal initial test pressure requirements, and much higher 
than normal burst pressure capability creates an equivalent level of 
safety for these non-DOT specification fire extinguishers when compared 
to DOT

[[Page 85395]]

specification cylinders. We expect the same level of safety will be 
achieved in handheld and fire suppression system service.
    Note that the changes made in this final rule do not affect the 
description and classification of large fire extinguishers (see HM-
215M, 80 FR 1075, 1/8/2015 for background), which may contain 
``charging'' cylinders when transported as a completed fire 
extinguishing system provided they meet the conditions of Sec.  
173.309.

P-1560

    Air Products and Chemicals Inc. (Air Products) submitted a petition 
for rulemaking (P-1560) requesting that PHMSA revise Sec.  
173.304a(a)(2) to adopt the provisions of SP 13599. SP 13599 authorizes 
additional maximum filling densities for carbon dioxide and nitrous 
oxide to include 70.3 percent, 73.2 percent, and 74.5 percent 
respectively in DOT 3A, 3AA, 3AX, 3AAX, 3AL, and 3T cylinders with 
marked service pressures of 2000, 2265, and 2400 psig, subject to 
operational controls. In the NPRM, we did not propose to adopt this 
provision because it was already adopted in the HMR by HM-233F (81 FR 
3635).
    We received two comments related to P-1560 in this docket. 
Worthington Cylinder agreed with our determination in the NPRM that we 
had already adopted these provisions and therefore do not need to 
address them again. Independent Cylinder Training (ICT) submitted a 
comment proposing additional changes to Sec.  173.304a(a)(2). ICT 
requested that cylinders with a service pressure of 2015 psig be 
authorized for 70.3% fill density, like those with a service pressure 
of 2000 psig. Additionally, ICT requested that PHMSA add a provision to 
require that cylinders filled according to fill density be marked with 
the water weight of the cylinder to aid in the filling process.
    PHMSA response. ICT's understanding of filling density requirements 
for carbon dioxide is not correct. In the scenario it presents, a 
cylinder with a service pressure of 2015 psig is already authorized for 
a filling density of 70.3 percent for carbon dioxide. ICT's other 
proposal regarding marking of water weight on a cylinder is beyond the 
scope of this rulemaking and we suggest that ICT submit a separate 
petition for rulemaking on the issue. As previously stated, P-1560 
provisions were adopted into the HMR by rulemaking HM-233F, and 
therefore we are not addressing it in this final rule.

P-1563

    3M Corporation submitted P-1563 requesting that PHMSA address the 
regulatory confusion between marking requirements for overpacks in 
Sec.  173.25 and outside packages for certain thin-walled cylinders 
specified in Sec.  173.301(a)(9). The petitioner notes that the 
differing marking requirements in Sec. Sec.  173.25 and 173.301(a)(9) 
create confusion and make training difficult. This petition requests 
modification of the HMR to permit materials packaged in conformance 
with Sec.  173.301(a)(9)--except aerosols ``2P'' and ``2Q''--to display 
the ``OVERPACK'' marking described in Sec.  173.25, in lieu of the 
current requirement for ``an indication that the inner packaging 
conforms to prescribed specifications.''
    In the NPRM, we recognized that differing marking requirements in 
Sec. Sec.  173.25 and 173.301(a)(9) to communicate the same intended 
meaning may be causing confusion without enhancing safety. In order to 
address the petition and provide for greater clarity, PHMSA proposed to 
revise Sec.  173.301(a)(9) to authorize use of the ``OVERPACK'' marking 
as specified in Sec.  173.25(a)(3) as a method to satisfy the current 
requirement in paragraph (a)(1) to mark the completed package with an 
indication that the inner packagings conform to prescribed 
specifications for the listed cylinders. We agreed with 3M that the 
issue is more complex for 2P and 2Q containers as specified in 
Sec. Sec.  173.304, 173.305, and 173.306, and therefore did not propose 
to include 2P and 2Q in the allowance for the ``OVERPACK'' marking. We 
proposed additional instructional language that the combination package 
is not to be considered an ``overpack.''
    We received two comments on this issue. Alaska Air stated their 
opposition to the proposed changes. Alaska Air states that the proposed 
change is at variance with the existing Sec.  171.8 definition of 
combination package, which will result in additional confusion by the 
hazmat community, and that most shipments marked as proposed will be 
rejected by air carriers because the ``overpack'' mark will be placed 
on outer packages that are not overpacks.
    COSTHA also submitted comments regarding this issue. COSTHA 
``supports this [revision] in principle and agrees with PHMSA and the 
petitioner, 3M, that the differing marking requirements in Sec.  173.25 
and Sec.  173.301(a)(9) to communicate similar conditions may be 
causing confusion without enhancing safety.'' However, COSTHA also 
notes that the sentence, ``[d]isplay of the `Overpack' marking is not 
an indication that this combination package is an overpack'' is 
confusing, and recommends that it be deleted.
    PHMSA response. PHMSA agrees with Alaska Airlines and COSTHA that 
the proposed change could result in more confusion than it would 
resolve and would not promote compliance with the HMR. Upon further 
consideration, we do not believe a regulatory change is warranted. The 
marking requirement in Sec.  173.301(a)(9) applies to a completed 
package. The requirements in Sec.  173.25 apply to an enclosure used to 
protect or consolidate completed packages. The ``OVERPACK'' applies to 
the enclosure when specification packages are required and are not 
visible. We do not view this as overly confusing. Therefore, in this 
final rule we are not adopting any changes proposed in the NPRM based 
on P-1563.

P-1572

    Barlen and Associates submitted P-1572 requesting that PHMSA 
explicitly state in Sec.  173.312 that for liquefied compressed gases 
in Multiple-Element Gas Containers (MEGCs), the filling density of each 
pressure receptacle must not exceed the values contained in Packing 
Instruction P200 of the UN Model Regulations, as specified in Sec.  
173.304b, and the contents of each DOT-specification cylinder cannot 
exceed the densities specified in Sec.  173.304a(a)(2).\5\ The 
definition of MEGC in Sec.  171.8 states DOT-specification cylinders 
are not authorized as part of MEGCs and accordingly, we are not 
including the petitioned language referring to DOT-specification 
cylinders in Sec.  173.312. DOT-specification cylinders filled with 
liquefied compressed gas must be filled in accordance with the 
instructions found in Sec.  173.304 and Sec.  173.304a, including 
filling density limitations.
---------------------------------------------------------------------------

    \5\ Note that the petition specifically referenced the 17th 
edition of the UN Model Regulations; however, we will propose a 
change that references the edition currently incorporated by 
reference in Sec.  171.7 because we biennially update the edition 
for harmonization with international standards.
---------------------------------------------------------------------------

    Requirements for shipping MEGCs are specified in Sec.  173.312. 
Specifically, Sec.  173.312(b) details the filling requirements for 
MEGCs and states, ``[a] MEGC may not be filled to a pressure greater 
than the lowest marked working pressure of any pressure receptacle [and 
a] MEGC may not be filled above its marked maximum permissible gross 
mass.'' The requirement that each pressure receptacle contained in the 
MEGC may not be filled above the working pressure of the lowest marked

[[Page 85396]]

working pressure of any pressure receptacle is clear for permanent 
(non-liquefied compressed) gases, which are generally filled by 
pressure; however, Sec.  173.312(b) does not contain a corresponding 
requirement addressing pressure receptacles containing a liquefied 
compressed gas, which are most often filled by weight. This lack of 
specificity for MEGCs containing liquefied compressed gas has led to 
some confusion on methods for their proper filling. Therefore, in the 
NPRM, we proposed to specify the filling ratio requirements for 
pressure receptacles.
    We received comments supporting this proposal from CGA and 
Worthington Cylinder, and comments requesting modification to the 
proposed language from FIBA Technologies (FIBA).
(1) Manifolding While Filling
    We received a comment from FIBA stating their opposition to the 
sentence ``Manifolding while filling is not authorized.'' FIBA states 
there would be no safety benefit to removing the manifold for many 
MEGCs during filling because the MEGCs can be filled safely with the 
manifold in place.
    PHMSA response. We agree with FIBA's comment. It was not our intent 
to require the disconnection of the manifold during filling. Rather, 
our intent is to require that each pressure receptacle is filled 
individually when loading liquefied compressed gases. We acknowledge 
that the manifold may remain in place as long as there are measures in 
place to prevent more than one cylinder from being filled at a time 
when loading liquefied compressed gas. Therefore, in the final rule we 
will remove the sentence ``[m]anifolding during filling is not 
authorized.''
(2) Filling With Non-Liquefied Gases
    FIBA also noted that our proposed revision accidently removed the 
language currently in Sec.  173.312(b)(1) relevant to the filling of 
MEGCs with ``permanent'' or non-liquefied gas.
    PHMSA response. This was not our intent; therefore, in the final 
rule we will move the current language for permanent gases in Sec.  
173.312(b)(1) to new Sec.  173.312(b)(1)(i) and insert the language 
appropriate for filling with liquefied compressed gases in the new 
Sec.  173.312(b)(1)(ii). Additionally, we agree with FIBA's suggestion 
that there is value in specifying that Sec.  173.312(b)(1)(i) applies 
to filling MEGCs with permanent, non-liquefied compressed gases, which 
are filled by pressure, while Sec.  173.312(b)(2)(ii) applies to 
liquefied gases, which are filled by weight.
    In this final rule, we are adopting P-1572, with the modifications 
noted above. PHMSA emphasizes that this change does not impose a new 
burden, as adoption of this proposal only emphasizes an important 
safety requirement already stated in Sec.  173.304b for UN pressure 
receptacles.

P-1580

    HMT Associates submitted P-1580 requesting that PHMSA revise 
Sec. Sec.  173.302(f)(2) and 173.304(f)(2) to require that the burst 
pressure of a rupture disc align with CGA S-1.1 for DOT 39 cylinders 
filled with an oxidizing gas and offered for transportation by air. 
Specifically, as prescribed in 4.2.2 of CGA S-1.1, the required burst 
pressure of the rupture disc ``shall not exceed 80 percent of the 
minimum cylinder burst pressure and shall not be less than 105 percent 
of the cylinder test pressure.''
    Section 173.301(f) states that a cylinder filled with a compressed 
gas and offered for transportation ``must be equipped with one or more 
[pressure relief devices (PRDs)] sized and selected as to type, 
location and quantity and tested in conformance with CGA S-1.1 
[Pressure Relief Device Standards--Part 1--Cylinders for Compressed 
Gases, Fourteenth Edition (2005)] and CGA S-7 [Method for Selecting 
Pressure Relief Devices for Compressed Gas Mixtures in Cylinders 
(2005)].'' Sections 172.302(f)(2) and 172.304(f)(2) specify that the 
rated burst pressure of a rupture disc for DOT 3A, 3AA, 3AL, 3E, and 39 
cylinders, as well as that for UN ISO 9809-1, ISO 9809-2, ISO 9809-3, 
and ISO 7866 cylinders containing oxygen, compressed; compressed gas, 
oxidizing, n.o.s.; or nitrogen trifluoride, must be 100 percent of the 
cylinder minimum test pressure with a tolerance of `plus zero' to minus 
10 percent.
    In response to PHMSA's NPRM entitled ``Hazardous Materials: 
Miscellaneous Amendments'' published on September 29, 2010 (75 FR 
60017) under Docket No. PHMSA-2009-0151 (HM-218F), HMT Associates 
submitted a late-filed comment that identified a potential discrepancy 
between the HMR and CGA S-1.1. Specifically, this commenter stated the 
HMR have different PRD settings than CGA S-1.1 for DOT 39 cylinders 
that make it virtually impossible to comply with both the HMR and CGA 
S-1.1. Sections 173.302(f)(2) and 173.304(f)(2) require the rated burst 
pressure of a rupture disc for DOT 3A, 3AA, 3AL, 3E, and DOT 39 
cylinders to be 100 percent of the cylinder minimum test pressure with 
a tolerance of `plus zero' to minus 10 percent, whereas section 4.2.2 
of CGA S-1.1 requires the rated burst pressure of the rupture disc on 
DOT 39 cylinders to be not less than 105 percent of the cylinder test 
pressure.
    In the NPRM, PHMSA proposed to revise Sec.  173.301(f) as it 
applies to DOT 39 cylinders to alleviate any confusion and conflict 
between the PRD requirements in Sec.  173.301(f) and those in 
Sec. Sec.  173.302(f)(2) and 173.304(f)(2) with respect to minimum 
burst pressure of pressure relief devices on a DOT 39 cylinder used for 
the transport of compressed and liquefied oxidizing gases by air.
    We received comments from HMT Associates and Worthington Cylinder 
regarding P-1580. Both comments correctly noted that in the NPRM we 
failed to amend the regulatory text in Sec. Sec.  173.302 and 173.304 
as we stated in our NPRM discussion.
    PHMSA response. We agree with HMT Associates' comment noting that 
the proposed language in Sec.  173.301(f)(4)(iv) is not strictly 
necessary, because by revising Sec. Sec.  173.302(f)(2) and 
173.304(f)(2) we will have brought the HMR into alignment with CGA S-
1.1 requirements. However, we will maintain the reference to the new 
requirements in Sec.  173.301(f)(4)(iv) to increase the visibility of 
the new requirements. We did not receive any comments opposed to the 
proposed change. Therefore, in the final rule, we are amending 
Sec. Sec.  173.302 and 173.304 to align with CGA S-1.1 requirements for 
DOT 39 cylinders for oxidizing gases transported by air. To avoid 
placing cylinders in conformance with the current requirements of 
Sec. Sec.  173.302(f)(2) and 173.304(f)(2) out of service, we will 
allow cylinders filled prior to the effective date of this rulemaking 
that meet the current requirements of the HMR to remain in service 
until the end of their useful lives.

P-1582

    Water Systems Council submitted P-1582 requesting that PHMSA revise 
Sec.  173.306(g), which provides a limited quantity exception for water 
pump system tanks, by permitting tanks manufactured to American 
National Standards Institute (ANSI)/Water Systems Council (WSC) 
standard PST 2000-2005 (2009) to be authorized for transport.
    The ANSI/WSC standard PST 2000-2005 prescribes minimum performance 
and construction requirements for pressurized storage tanks for service 
in water well systems with a maximum factory pre-charge pressure of 40 
psig (280 kPa), to be operated in ambient air temperatures up to 120 
[deg]F (49 [deg]C), with

[[Page 85397]]

maximum working pressures not less than 75 psig (520 kPa) and not 
greater than 150 psig (1,000 kPa) and tank volumes not exceeding 120 
gallons (450 L). The standard was developed by a group of WSC members 
comprised of leading U.S. manufacturers of pressurized water storage 
tanks for water wells to define and promote--through voluntary written 
standards--minimum performance and construction requirements for 
pressurized water storage tanks for service in water well systems. 
Aligning the HMR with this industry standard will provide minimum 
requirements for pressurized water storage tanks for water wells that 
provide at least an equivalent level of safety as currently provided in 
the HMR.
    The revised requirements for water pump system tanks in this final 
rule authorize tanks to be tested to the manufacturer's specified 
maximum working pressure instead of the current one size fits all 
requirement of 100 psig. Further, it allows water pump system tanks to 
be charged with helium in addition to the currently authorized 
nitrogen. The requirements in this final rule allow additional 
flexibility for manufacturers compared to current requirements. 
Therefore, PHMSA does not expect this amendment to impose costs. PHMSA 
received one comment in support of this proposal from Worthington 
Cylinder.
    In the NPRM, we proposed to change the pneumatic test requirement 
from 100 psig to the manufacturer's specified maximum working pressure 
because the industry standard allows for maximum working pressures 
greater than 100 psig (i.e., up to 150 psig as stated above). In this 
final rule, we will specify that the pneumatic test may not exceed 150 
psig, which aligns with ANSI/WSC PST 2000-2005 maximum working pressure 
for a water pump system tank. Pneumatic pressure tests present 
additional risks to testing personnel, and this modification is 
intended to reduce risk by clarifying the maximum test pressure allowed 
while remaining aligned with the industry standard.
    We are making several additional editorial changes to the layout 
and language of Sec.  173.306(g) in order to clarify the intent of the 
provision. Specifically, we are modifying the introductory paragraph of 
Sec.  173.306(g) to clarify our intent to allow the tanks to be filled 
with air, nitrogen, or helium up to 40 psig at time of manufacture, 
referred to in ANSI/WSC PST 2000-2005 as a ``pre-charge.'' Further, we 
are replacing the word ``charged'' with ``pre-charge'' throughout the 
paragraph to clarify that the manufacturer's pre-charge pressure is the 
pressure that should be used in calculations, where appropriate.
    We are modifying Sec.  173.306(g)(1) to explain clearly the maximum 
allowable working pressure limits of water pump system tanks. The 
requirement that these tanks may be operated in ambient air 
temperatures of up to 49 [deg]C (120 [deg]F) with a maximum working 
pressure not less than 517.1 kPa (75 psig) and not greater than 1034.2 
kPa (150 psig) is taken from the ANSI/WSC PST 2000-2005 standard. Our 
intent is to impose a limit on the marked maximum working pressure for 
a water pump tank system at 150 psig, (i.e., the upper end of the 
maximum working pressure), to ensure pneumatic testing is not conducted 
above this pressure at time of manufacture to prevent increased dangers 
for testing employees. Given that the new MAWP limit in Sec.  
173.306(g)(1) aligns with the industry standard and is above the limit 
for water distribution piping operations, PHMSA does not believe that 
this requirement will introduce any additional burdens on 
manufacturers.
    We are removing the phrase ``concave dome tanks'' from Sec.  
173.306(g)(3) for clarity because we consider this language to be 
redundant to the requirement in Sec.  173.306(g)(1) that requires all 
tanks to have heads concave to pressure.
    Finally, we are not adopting proposed paragraph (g)(4), which 
discussed a design leakproofness test for composite tanks. We do not 
believe that requiring this test for composite tanks is necessary in 
the HMR. Our main transportation safety concern with water pump system 
tanks remains their burst pressure, and we believe that inclusion of 
the proposed design hydrostatic leakproofness test for composite tanks 
will increase confusion. All tanks, steel and composite, are subject to 
a pneumatic proof pressure test at the manufacturer's maximum allowable 
working pressure at time of manufacture (see Sec.  173.306(g)(1)). All 
tank designs, both steel and composite, must also have a burst pressure 
at least 6x the pre-charge pressure at 21.1 [deg]C (70 [deg]F) or 3x 
the manufacturer's specified maximum working pressure, whichever is 
greater, as proposed. These modifications to the proposed language are 
intended to increase clarity without making any substantive changes to 
the provisions proposed in the NPRM.
    In this final rule, PHMSA will adopt provisions of P-1582 as 
proposed with the modification noted above.

P-1592

    The CGA submitted P-1592 requesting that PHMSA replace the 2005 
edition of CGA S-1.1, Pressure Relief Device Standards--Part 1--
Cylinders for Compressed Gases with the 2011 edition as referenced in 
the HMR.
    CGA S-1.1 provides standards for selecting the correct pressure 
relief device (PRD) to meet the requirements of Sec.  173.301(f) for 
over 150 gases. It provides guidance on when a pressure relief device 
can be optionally omitted and when one's use is prohibited, as well as 
direction on pressure relief device manufacture, testing, operational 
parameters, and maintenance. CGA S-1.1 is available for purchase online 
and will be available for public inspection at the Hazardous Material 
Information Center after publication of the final rule.
    This minor update to the regulations improves the timeliness and 
clarity of industry standards that are incorporated by reference. It 
supports the goal of facilitating the use of industry standards and 
reducing the burdens associated with references to outdated material.
    Bancroft Hinchey, Worthington Cylinder, NAFED, CGA and FIBA 
Technologies submitted comments supporting incorporation by reference 
of the 2011 edition of CGA S-1.1. FIBA Technologies additionally 
identified an inconsistency with the HMR and new S-1.1 requirements. 
FIBA Technologies correctly noted that the requirements for pressure 
relief devices in Sec.  173.302a(c)(4)(ii) conflict with the 2011 
edition of CGA S-1.1 that we are incorporating by reference in this 
rulemaking. Accordingly, we are amending Sec.  173.302a(c)(4)(ii) to 
reflect that PRDs are optional for hydrogen tube trailers. Shippers are 
not required to install PRDs on tubes (cylinders longer than 12 feet) 
shipped in accordance with this paragraph, however their continued use 
and installation is authorized. This change maintains regulatory 
flexibility and alignment with accepted industry practice. This change 
does not impose any new requirements and increases regulatory 
flexibility by allowing hydrogen tube trailer shippers the option of 
continuing to use PRDs. In this final rule, we are incorporating by 
reference CGA S-1.1, 2011 as proposed.

P-1596

    Chemically Speaking, LLC submitted P-1596 which requested that 
PHMSA revise the HMR pertaining to salvage drums. Specifically, P-1596 
proposed amending Sec.  173.3(d) to allow Class 4 and Class 5 materials 
to be placed in salvage cylinders.

[[Page 85398]]

    Three commenters commented on this proposal. Dow Chemical Company 
and Worthington Cylinder supported the adoption of the petition as 
proposed. CGA opposed the adoption of the petition on the basis of 
safety, stating that they do not support revising salvage drum 
provisions in the HMR to allow Class 4 and Class 5 to be placed in 
salvage vessels because chemically reactive materials may produce 
pressures exceeding their pressure ratings. CGA suggests that a special 
permit or approval should be required for this activity.
    PHMSA response. We agree with Dow and Worthington and do not agree 
with CGA's comment. We proposed to allow the use of salvage cylinders 
(emphasis added), which are much more robust packagings than the 
salvage drums that CGA mentions. PHMSA acknowledges that the NPRM 
discussion of this proposal may have led to CGA's overly broad 
interpretation PHMSA's intent because we used the term ``drum'' even 
though the petition only applies to salvage cylinders. There is 
currently no restriction preventing shippers from placing Class 4 and 
Class 5 materials in salvage drums. Salvage cylinders are currently 
authorized to transport liquefied gases (such as carbon dioxide) and 
many toxic gases (Division 2.3). These materials are both high and low 
pressure so the salvage cylinders must be constructed and designed to 
handle the possible pressures of the packaged materials at temperatures 
up to 55 [deg]C. Salvage cylinder design criteria ensure safety and 
containment of a leaking cylinder so it can be transported to a 
disposal facility. Adding Class 4 and Class 5 materials will not create 
any significant change in the risk when using salvage cylinders as long 
all the requirements of Sec.  173.3(d) are met. No Class 4 and Class 5 
materials can be as toxic as the Division 2.3 or Division 6.1 materials 
currently allowed, nor can they generate pressure that would exceed the 
pressures of the Division 2.1, 2.2, or 2.3 materials currently allowed. 
Thus, we believe adding these materials as authorized in salvage 
cylinders will maintain the same level of safety established by the 
regulations.
    CGA also suggested allowing Class 4 and Class 5 materials to be 
placed in salvage cylinders under the provision of an approval.
    PHMSA response. We believe a requirement to receive an approval to 
use a salvage cylinder for Class 4 and Class 5 materials to be 
impractical in emergency situations. Additionally, as we have not 
identified any increased risk by providing this general allowance, 
imposing a burden on users to obtain an approval would also not be 
practical. We do not believe there will be any decrease in safety by 
allowing shippers to place Class 4 and Class 5 materials in more robust 
salvage cylinders. Therefore, we are adopting P-1596 as proposed, and 
amending Sec.  173.3(d) accordingly.

P-1622

    Worthington Cylinder submitted P-1622 requesting that PHMSA limit 
the internal volume of DOT 39 cylinders containing liquefied flammable 
gas to 75 cubic inches (in\3\), to correct an error dating to 2002.
(1) 75 Cubic Inch Limit
    Prior to the publication of HM-220D (67 FR 51626; Aug. 8, 2002), 
the HMR restricted the internal volume of DOT 39 cylinders to 75 in\3\ 
for all non-liquefied flammable compressed gases and the following 
flammable liquefied gases: Cyclopropane, ethane, ethylene and liquefied 
petroleum gas. In the HM-220 NPRM (63 FR 58460; Oct. 30, 1998), we 
proposed to increase the applicability of this restriction to all 
flammable liquefied gases, but did not adopt the change on the basis of 
negative comments in the HM-220D final rule. The HM-220D final rule, 
however, contained a drafting error that removed the 75 in\3\ 
restriction from liquefied gases completely, which was not our intent.
    Worthington Cylinder submitted P-1622 on July 19, 2013, requesting 
that PHMSA impose a volume restriction of 75 in\3\ on DOT 39 cylinders 
containing the liquefied gases cyclopropane, ethane, ethylene, and 
liquefied petroleum gas. On October 10, 2014, Worthington Cylinder 
submitted a supplement to P-1622, requesting that PHMSA restrict the 
volume of DOT 39 cylinders containing any liquefied flammable gas to 75 
cubic inches. In the NPRM, we proposed to adopt this second proposal 
and restrict the volume of DOT 39 cylinders containing any liquefied 
flammable gas to 75 cubic inches.
    CGA and Worthington Cylinder submitted comments supporting our 
proposed action to restrict the volume of DOT 39 cylinders containing 
any liquefied flammable gas to 75 cubic inches. We received comments 
from Worthington Cylinder, Ford Motor Company, Amtrol, Chemours, 
COSTHA, and Honeywell requesting that we create an exception to the 
proposed 75 in\3\ limit for ASHRAE A2L ``mildly flammable'' gases. We 
did not receive any comments directly opposed to the creation of a 
general 75 in\3\ limit for liquefied flammable gases in DOT 39 
cylinders. The commenters explained that, in the years since the 75 
in\3\ restriction was inadvertantly deleted, they have begun safely 
transporting certain Division 2.1 refrigerant gases in DOT 39 cylinders 
larger than 75 in\3\. They also submitted technical data describing the 
properties of ASHRAE A2L ``mildly flammable'' gases and demonstrated 
the performance of a DOT 39 cylinder with a capacity over 75 in\3\ 
filled with an A2L gas in a bonfire test.
    PHMSA response. In this final rule, we are modifying our proposed 
change to Sec.  173.304a and imposing a 75 in\3\ limit on the capacity 
of DOT 39 cylinders containing the following liquefied flammable gases: 
Cyclopropane, ethane, ethylene and liquefied petroleum gas. This course 
of action will correct the inadvertent error we made in HM-220D and 
aligns with PHMSA's safety advisory notice published April 24, 2017 
(PHMSA-2016-14; 82 FR 18967). This will also sufficiently address the 
economic concerns raised by Worthington Cylinder, Ford Motor Company, 
Amtrol, Chemours, COSTHA, and Honeywell regarding the applicability of 
the 75 in\3\ limit for hydrofluoroolefin and dihalogenoalkane 
refrigerants.
(2) Chemicals Under Pressure
    Dow Chemical Company submitted a comment requesting clarification 
about the size limitation for chemicals under pressure in Sec.  
173.302a(a)(3).
    PHMSA response. The limit is only intended to apply to Division 2.1 
(flammable gas) chemical under pressure. However, as we noted in the 
NPRM, the 50 L limit is much larger than the maximum size authorized 
for the DOT 39 specification in Sec.  178.65. This discrepancy was an 
unintentional outcome of a harmonization effort with international 
requirements for non-refillable cylinders, which allow larger sizes 
than the HMR allow (see Docket No. PHMSA-2012-0027 (HM-215L); 78 FR 
988). To reduce confusion introduced by the conflict of the 50 L 
quantity in Sec.  173.302a(a)(3) and the capacity limts of the 
specification, we are deleting the reference to ``50 L (3050 in\3\)'' 
and replacing it with reference to the DOT 39 specification capacity 
limits--1526 in\3\ for a service pressure of 500 psig or less, and 277 
in\3\ for a service pressure of greater than 500 psig.

P-1626

    The CGA submitted P-1626 requesting that PHMSA incorporate by 
reference (IBR) CGA C-1, Methods for Pressure Testing Compressed Gas 
Cylinders, Tenth Edition (2009) and revise the regulations regarding 
the

[[Page 85399]]

retesting of cylinders by the hydrostatic test as they are not only 
unclear to requalifiers, but also missing necessary information 
rendering the regulations unenforceable. Although the petition proposed 
the Tenth Edition, currently there is an Eleventh Edition (2016) 
available. In the NPRM, PHMSA proposed to incorporate by reference this 
most current version and requested comment regarding this action. We 
received no adverse comments related to adoption of the newest edition 
(i.e., CGA C-1-2016 (11th Ed.)) of the standard versus the Tenth 
Edition. However, we did receive numerous comments regarding the 
incorporation by reference of CGA C-1-2016 (11th Ed.) (``CGA C-1'') and 
associated revisions, which we will discuss in depth as follows.
    In this final rule, PHMSA is adopting clarifying language and 
incorporating by reference the CGA C-1 standard, as proposed in P-1626. 
CGA C-1 provides more detailed instructions and illustrations for use 
by cylinder requalifiers and manufacturers than what is possible in the 
HMR and addresses the deficiencies detailed in the petition. This 
incorporation by reference applies to the following sections: 
Sec. Sec.  178.36, 178.37, 178.38, 178.39, 178.42, 178.44, 178.45, 
178.46, 178.47, 178.50, 178.51, 178.53, 178.55, 178.56, 178.57, 178.58, 
178.59, 178.60, 178.61, 178.65, 178.68, 180.205, and 180.209. The 
incorporation of CGA C-1 supports the goal of increasing compliance and 
improving overall safety as its reference increases clarity and 
provides enhanced guidance compared to the current language in the HMR. 
Cylinder requalifiers and manufacturers must comply with CGA C-1 
requirements for pressure testing cylinders, as well as equipment 
accuracy and calibration. Specific clarifications include instructions 
for performing volumetric expansion tests using both the water-jacket 
and direct expansion methods, as well as a provision for retesting in 
case of equipment failure or operator error and re-naming the 
``hydrostatic test'' paragraph to ``pressure test'' to align more with 
industry accepted nomenclature. PHMSA believes that CGA C-1's inclusion 
of ``operator error'' as a condition allowing a repeated test at a 
higher pressure will prevent the condemnation of cylinders that are 
safe for continued use. Revising the HMR to incorporate by reference 
CGA C-1 will provide the desired clarification without imposing 
requirements that are potentially costly or unnecessarily difficult.
(1) Response to Hydro-Test Products
    We received numerous comments regarding incorporation by reference 
of CGA C-1, and about interpretation of CGA C-1 requirements. Hydro-
Test Products \6\ submitted a comment requesting clarification of CGA 
C-1 requalification requirements compared to the current 
requalification requirements in part 180, subpart C, of the HMR. Hydro-
Test Products states,
---------------------------------------------------------------------------

    \6\ PHMSA notes that Jeff Elliot, Noble Gas Solutions, Anthony 
King, W Andrews, and Scuba Do submitted comments supporting the 
Hydro-Test Products comment and opposing the incorporation of CGA C-
1. While the discussion below focuses on the specific comments from 
Hydro-Test Products, it also addresses the subject matter raised by 
these other comments supporting the Hydro-Test Products comment.

    The authors of the CGA C-1 pamphlet have included definitions 
and examples of calibration and accuracy for Expansion Indicating 
Devices (EID) and Pressure Indicating Devices (PID) that will 
restrict most all current licensed cylinder re-qualifiers from 
performing cylinder re-qualification. Furthermore, there are 
statements in the C-1 that discriminate against procedures and 
equipment components that have been utilized in a safe, consistent 
---------------------------------------------------------------------------
and accurate manner for many years.

    PHMSA response. We disagree with Hydro-Test Products and address 
the issues they raise below.
(a) Expansion Indicating Device Accuracy
    Hydro-Test Products describes a burette arrangement with 4 burettes 
with full scales of 0-25, 0-50, 0-125 and 0-360 cubic centimeters (cc) 
and explains their belief that incorporation by reference of CGA C-1 
will significantly restrict the usable range of the burettes to half of 
the burette's scale, instead of the much broader range that they 
believe are authorized under the current HMR.
    PHMSA response. Hydro-Test Products understanding of the HMR's 
current requirements is not correct. The HMR currently require use of 
burettes in the same manner prescribed in CGA C-1. Hydro-Test Products 
misunderstanding appears to be grounded in the final rule published on 
May 28, 1996, known as HM-220A, (61 FR 26750). HM-220A created the 
requirement that expansion indicating devices (EID), such as burettes 
or scales, must be certified as having an accuracy of <plus-minus>0.5 
percent, of its full range, and must be accurate to <plus-minus>1.0 
percent of the total expansion of any cylinder tested or 0.1 cubic 
centimeter, whichever is larger. These accuracy requirements, as 
discussed in the HM-220A final rule (61 FR 26751), are separate and 
distinct from the requirement that the EID permit reading to <plus-
minus>1 percent of the total expansion. The reading requirements are 
intended to address the resolution of the EID, which is not the same as 
the accuracy of the EID. In the example of the burette with a full 
scale of 50 cc, with an accuracy grade of <plus-minus>0.5 percent and 
increments of 0.1 cc (mid-point interpolation allowed to 0.05), the 
resolution would permit reading down to 5 cc (i.e., interpolation to 
0.05 is 1 percent of 5 cc), but the accuracy of the device would not. A 
burette with a full scale of 50 cc and full-scale accuracy of <plus-
minus>0.5 percent has an expected deviation of <plus-minus>0.25 cc. The 
device may only be used to measure total expansion greater than 25 cc, 
because at total expansions lower than 25 cc, the expected deviation 
will be greater than <plus-minus>1 percent of the total expansion. 
Using the 5 cc example, a 0.25 cc deviation (i.e., the expected 
deviation for a 50 cc burette with an accuracy grade of <plus-minus>0.5 
percent) at a total expansion of 5 cc would be a 5% deviation, and 
would not meet the requirement that the EID is accurate to <plus-
minus>1% of the total expansion.
    Moreover, we do not agree that incorporation by reference of CGA C-
1 will impose new cost burdens upon cylinder requalifiers because the 
current regulatory standard has been in place since 1996, and the 
requirements will not change with incorporation by reference of CGA C-
1. Hydro-Test Products states that a similar issue exists for 
requalifiers using a scale as their EID. Our response is the same: The 
current regulatory standard has been in place since 1996, and the 
requirements will not change with incorporation by reference of CGA C-
1.
(b) Total and Permanent Expansion Accuracy
    Hydro-Test Products asks how EIDs can be used to measure permanent 
expansion when that permanent expansion is a much lower value that the 
total expansion, i.e. the permanent expansion is out of the range 
allowed for the total expansion.
    PHMSA response. Hydro-Test Products is correct that permanent 
expansion values are much lower than total expansion values. The HMR 
has always accepted a greater accuracy deviation for permanent 
expansion, and this does not change in CGA C-1. Accuracy requirements 
for EIDs continue to be expressed in terms of the total expansion 
value.
(c) Foreknowledge of Total Expansion
    Hydro-Test Products asks, ``[s]ince there is no indication of the 
total expansion value on DOT specification

[[Page 85400]]

cylinders, how is a re-qualifier supposed to know what burette or scale 
is applicable and within the proposed regulations for a given test?''
    PHMSA response. If a requalifier is completely unaware of the 
approximate expected total expansion for a cylinder, the requalifier 
may pressurize the cylinder at or below 90 percent of test pressure, 
which will give an approximate value for total expansion, allowing the 
requalifier to select the proper EID for the test. If the operator errs 
and the cylinder is tested using an EID that cannot measure the total 
expansion to <plus-minus>1 percent, he or she may repeat the test up to 
two times, in accordance with CGA C-1 section 5.7.1. Note that 
pressurizing the cylinder at or below 90 percent of test pressure does 
not constitute a test.
(d) Pressure Indicating Device Accuracy
    Hydro-Test Products describes a scenario with four pressure 
indicating devices (PIDs) with the understanding that CGA C-1 will 
significantly limit the usable range of the gauges.
    PHMSA response. We acknowledge that there are other ways to 
demonstrate compliance with the accuracy requirements for PIDs (e.g. 
certifying gauges at pressures lower than their manufacturer's rated 
full scale). We believe this practice is in accordance with the HMR and 
with CGA C-1 because a gauge calibrator has, in effect, certified a 
gauge to better than a <plus-minus>0.5 percent full scale accuracy when 
he or she calibrates the gauge to demonstrate <plus-minus>1 percent 
accuracy at points lower than the normally usable range of the gauge 
based on the manufacturer's rated accuracy. The <plus-minus>1 percent 
accuracy requirement is only a minimum standard, and gauge 
manufacturers or other entities certifying the accuracy are free to 
demonstrate that the gauge meets the <plus-minus>1 percent requirement 
at other, lower points on the gauge.
    The examples provided in CGA C-1 are only a guide, and should not 
be used to prevent the use of PIDs at lower pressures provided the 
gauge calibrator documents the calibration points on the calibration 
certificate. The minimum accuracy and readability standards are such 
that it limits the use of any PID to (the upper) half the gauge, 
however, there is no limitation on using a gauge certified to be more 
accurate across its full range, thus allowing broader use of the gauge. 
PHMSA reviewed this practice in Letter of Interpretation Ref. No. 14-
0112, and at this time we have no reason to believe that this practice 
is unsafe. To clarify our intent further to continue to allow this 
practice, in this final rule we are not requiring compliance with CGA 
C-1 paragraph 5.3.2.2, which discusses accuracy requirements for PIDs, 
if the required accuracy of the PID can be demonstrated by other 
recognized means such as calibration certificates.
    Rather we are maintaining the HMR's current PID accuracy 
requirements in Sec.  180.205(g)(3)(i). Voluntary compliance with CGA 
C-1 5.3.2.2 is authorized and will meet the HMR's accuracy requirements 
for PIDs used for cylinder requalification, as will the practice of 
demonstrating accuracy through maintenance of a calibration certificate 
showing the gauge has been certified to meet the accuracy requirements 
at lower points. Regardless of the method used to determine the usable 
range of the gauge, the cylinder requalifier must verify that the 
system is accurate to within 1 percent of the test pressures to be 
tested that day, as provided in CGA C-1 paragraph 5.5.
(e) Reference Zero Expansion
    Hydro-Test Products requests clarification of the term ``reference 
zero expansion'' in CGA C-1, sections 3.2.22.
    PHMSA response. In the verification process, it is critical that 
the calibrated cylinder show zero expansion to indicate that the system 
set-up is accurate and ready for testing. The term ``reference zero 
expansion'' is intended to clarify that when reading the calibrated 
cylinder's permanent expansion during verification, an expansion 
reading of <plus-minus>0.1cc or <plus-minus>0.1 percent of total 
expansion, whichever is larger, is accepted as zero.
(f) Daily Verification
    Hydro-Test Products states that the requirement to verify all test 
equipment to be used that day is impossible for those companies that 
are utilizing burette systems on the volumetric tester and generally 
unnecessary.
    PHMSA response. We disagree. This is a long-standing requirement 
that is currently found in the HMR in Sec.  180.205(g)(4). All PIDs, 
EIDs, and water jackets that are to be used that day must be verified 
under the current requirements of the HMR. We do not believe any 
additional costs will be imposed by incorporating CGA C-1 because this 
industry standard has the same requirements as are already required for 
cylinder requalifiers under the HMR.
(g) Calibrated Cylinders as Surge Tanks
    Hydro-Test Products and Galiso question the reasoning for CGA C-1's 
prohibition on the use of a calibrated cylinder as a ``surge tank'' 
used to slow pumping speeds when testing smaller cylinders.
    PHMSA response. Observations from PHMSA field investigators suggest 
that industry already largely complies with this requirement. We have 
safety concerns that exposure to unregulated pressure surges and high 
temperatures may render the calibrated cylinder unsuitable for its 
intended purpose. If repeatedly exposed to unregulated pressure surges, 
the calibrated cylinder may experience additional permanent expansion, 
rendering it incapable of being used to verify the system's accuracy on 
a daily basis. The daily verification process depends on the calibrated 
cylinder giving a precisely known expansion value at a given pressure. 
If the calibrated cylinder begins stretching too much, for example, a 
cylinder requalifier may adjust the equipment so that the reading 
returns to the expected value, not realizing that he has just brought 
his equipment out of alignment in his attempt to calibrate with an 
overstretched cylinder. This would cause inaccurate tests whenever that 
calibrated cylinder is used to verify the system before a day of tests.
(h) Conclusion
    Finally, Hydro-Test Products states, ``[a]s we have hoped to have 
presented in these comments, the incorporation of the C-1 into the 
regulations will only confuse cylinder re-qualifiers more, while 
imposing nearly impossible accuracy requirements at a greater cost with 
absolutely no benefit in safety.''
    PHMSA response. We disagree with Hydro-Test Products' conclusion. 
As we have shown, incorporation of CGA C-1 will not impose additional 
regulatory burdens on requalifiers. CGA C-1 combines the HMR's current 
regulatory requirements for pressure testing with diagrams, 
illustrations, step-by-step guidelines, trouble-shooting procedures, 
and technical appendices that provide requalifiers with all the 
information they need to requalify cylinders safely and successfully. 
The creation of flexibility for reference zero expansion will decrease 
the time wasted by requalifiers calibrating their systems every day 
without compromising accuracy. PHMSA believes, based on experience 
conducting compliance inspections at cylinder requalification 
facilities, that the additional guidance provided by CGA C-1 (diagrams, 
troubleshooting guides, technical appendices) will encourage compliance 
with cylinder requalification standards.

[[Page 85401]]

(2) Response to Other Commenters
(a) System Failure or Operator Error
    FIBA submitted a comment requesting that we reevaluate the 
requirements related to system failures or operator error during the 
pressure test required after cylinder manufacture.
    PHMSA response. We agree that the requirements need further 
clarification. It was our intention to align with the requirements in 
CGA C-1, section 5.7.2 for cylinder manufacture. In the event of 
equipment failure or operator error, cylinders may be repeat tested 
more than twice at time of manufacture, as long as the actual test 
pressure does not exceed 110 percent of the minimum test pressure and 
the stresses developed in the cylinder remain within its specification 
and design limitations. Therefore, we are inserting a reference to that 
provision in each cylinder manufacture pressure testing paragraph. Note 
that this does not apply to 3AL cylinders, which, due to the 
differences in ductility between aluminum and steel, are limited to a 
single repeat test.
(b) Clarification of Sec.  178.42(f)
    COSTHA submitted a comment requesting grammatical changes to the 
proposed Sec.  178.42(f) to clarify our intent. Section 178.42 
specifies two tests for DOT 3E cylinders. One cylinder from each lot 
must be burst tested, and must burst at a pressure of 6,000 psig 
without fragmenting or otherwise showing lack of ductility. Then 
following a successful burst test, each remaining cylinder in the lot 
must be examined under pressure of at least 3,000 psig, and not above 
4,500 psig, and show no defect. The cylinder manufacturer may only 
examine the cylinders at a pressure of 3,600 psig or greater if the 
cylinder that was burst-tested at 7,500 psig or greater.
    PHMSA response. We agree with COSTHA's comment that the proposed 
language in Sec.  178.42(f)(3)(ii) was ambiguous. In this final rule, 
we are reverting the language in Sec.  178.42(f) to the previous layout 
and language and adding the incorporation of CGA C-1. In our attempt to 
clarify the requirements in Sec.  178.42(f) we inadvertently made them 
more ambiguous.
(c) CGA C-1.1
    Hydro-Test Products, Bancroft Hinchey, ICT, Noble Gas Solutions, 
and FIBA noted that the CGA C-1.1 training material we cited in Sec.  
180.205(j), has been retracted by CGA and requested that we remove 
reference to it.
    PHMSA response. We agree with the commenters and will remove 
reference to CGA C-1.1 from Sec.  180.205(j), as it no longer applies 
as a resource.
(d) Burst Testing Accuracy
    Worthington Cylinder submitted a comment requesting clarification 
about whether CGA C-1 accuracy requirements apply to PIDs used when 
burst testing cylinders during manufacturing.
    PHMSA response. The answer is yes. In this final rule, we will 
modify the relevant sections of the part 178 specifications for 
cylinders to indicate that PIDs used for burst tests must meet the 
requirements of CGA C-1.
(e) Reference Zero Expansion
    Galiso submitted a comment requesting that we accept a value within 
<plus-minus>1 percent of readability as zero for daily verification. 
PHMSA does not agree. The allowance of <plus-minus>.1 percent of total 
expansion will decrease time spent by requalifiers during daily 
verification while ensuring that their system continues to meet 
accuracy requirements. PHMSA will not consider a new ``zero'' standard 
in this final rule.
(f) Repeat Tests for System Failure or Operator Error
    Galiso submitted a comment requesting an explanation for the 
limitation of two repeat tests in the case of system failure or 
operator error. When a cylinder is pressurized, it expands. This 
property is the basis of the volumetric expansion testing program. 
Volumetric expansion testing measures the volume of the cylinder at 
test pressure (elastic expansion), and compares it to the volume of the 
cylinder after pressure is removed (permanent expansion). When 
permanent expansion is more than 10 percent (or 12 percent for certain 
cylinders) of elastic expansion, the cylinder must be condemned. If a 
cylinder is pressurized to over 90 percent of test pressure and then 
the system fails or the operator errs, it will not return to its 
original state, rather it will exhibit permanent expansion and reduced 
expandability because the metal has been stretched. When the test is 
repeated the next day, the cylinder will exhibit less permanent 
expansion than the day before, because it started the test in an 
expanded state. PHMSA is concerned that allowing more than two repeat 
tests cycles will allow cylinders that should have been condemned to 
re-enter transportation.
(3) Corrections
(a) DOT 39 Burst Test
    In the review of the NPRM, PHMSA determined that we inadvertently 
removed the requirements for burst-testing DOT 39 cylinders from Sec.  
178.65(f). In this final rule, we are re-inserting burst test 
requirements with language incorporating CGA C-1 calibration and 
accuracy requirements for burst testing into Sec.  178.65(f).
(b) Incorrect Usage of the Word ``Condemn''
    In the review of the NPRM, PHMSA determined that we inadvertently 
replaced the word ``rejected'' with ``condemned'' in several cylinder 
manufacture pressure testing sections, specifically Sec. Sec.  178.46, 
178.47, 178.55, 178.56, and 178.65. This was not our intent. In this 
final rule, we will maintain the HMR's existing instructions for 
cylinders rejected during manufacture.
(4) Pneumatic and Hydraulic Proof Pressure Tests
    CGA C-1 provides instructions for conducting proof pressure tests 
both pneumatically (gaseous-based system) and hydraulically (liquid-
based system). For the purposes of part 178, subpart C, a manufacturer 
may choose either system when a proof pressure test is authorized. 
PHMSA would like to emphasize that pneumatic proof pressure test 
systems can present increased risks to test personnel due to the amount 
of energy stored in a cylinder filled to test pressure with a gas. 
Manufacturers must take this risk into account and develop systems to 
prevent the injury or death of their employees in the event of a 
catastrophic cylinder rupture at test pressure. The use of additional 
safety equipment such as blast shields, test cages, etc., is advisable 
to prevent possible injury to testing personnel and equipment.

P-1628

    CGA submitted P-1628 requesting that PHMSA incorporate by reference 
(IBR) CGA C-3-2005, Reaffirmed 2011, Standards for Welding on Thin-
Walled, Steel Cylinders, Seventh Edition into the HMR. Presently, the 
HMR incorporate the Fourth Edition of this standard, CGA C-3-1994. This 
publication contains information on welding process qualification, 
welding operator qualifications, tensile testing, bend testing, and 
radiographic inspection. The changes between the Fourth Edition and the 
Seventh Edition were predominantly editorial or technical in nature. 
The significant technical changes are summarized as follows and

[[Page 85402]]

can be reviewed in detail in the docket to petition P-1628: \7\
---------------------------------------------------------------------------

    \7\ PHMSA Docket ID: PHMSA-2013-0278.
---------------------------------------------------------------------------

    <bullet> Added section to the testing criteria to employ the use of 
macro etch samples in lieu of weld guided bend test and weld tensile 
testing when the cylinder size would not permit securing of proper size 
specimens.
    <bullet> Clarified the weld bend testing procedure, weld bend 
testing tooling, and proper clearances that are required in the 
tooling.
    <bullet> Clarified definitions for the welding procedure 
qualification and the welding operator weld qualification.
    <bullet> Added a tolerance section that indicates the plus and 
minus tolerances when a specific dimensional tolerance is indicated in 
the publication.
    <bullet> Added drawings to illustrate different weld joint designs.
    Bancroft Hinchey, Worthington Cylinder, NAFED, and CGA submitted 
comments supporting the incorporation of the Seventh Edition of CGA C-
3. Therefore, in this final rule, PHMSA is incorporating by reference 
CGA C-3-2005, Reaffirmed 2011, as proposed.
    Bancroft Hinchey requested clarification of training requirements 
for cylinder requalifiers.
    PHMSA response. Cylinder requalifiers meet the definition of 
``hazmat employee'' found in Sec.  171.8. All hazmat employees must be 
trained in accordance with 49 CFR part 172, subpart H, including 
function specific training. An employee working as a cylinder 
requalifier must be trained to perform that job function properly, 
including visual inspection of cylinders, but would not necessarily 
need welding training unless also performing a welding function subject 
to the HMR.

P-1629

    The CGA submitted P-1629 requesting that PHMSA incorporate by 
reference (IBR) CGA C-14-2005, Reaffirmed 2010, Procedures for Fire 
Testing of DOT Cylinder Pressure Relief Device Systems, Fourth Edition, 
into the HMR. Presently, the HMR incorporates the First Edition of CGA 
C-14-1979. Since the incorporation of this edition, CGA has revised the 
publication in 1992, 1999, 2005, and reaffirmed the publication in 
2010.
    This standard describes test procedures and apparatus for fire 
testing compressed gas cylinder safety (pressure) relief devices as was 
required by former Sec.  173.34(d) and current Sec.  173.301(f) of the 
HMR. The procedures are designed to provide a means of testing to DOT 
requirements anywhere with reliable test data and repeatable test 
results. The changes from the 1979 First Edition to the 2005 and 
Reaffirmed 2010 editions of CGA C-14 were predominantly editorial or 
technical in nature. The significant technical changes are summarized 
as follows and can be reviewed in detail in the docket to petition P-
1629: \8\
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    \8\ PHMSA Docket ID: PHMSA-2014-0012.
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    <bullet> Permitted the use of an alternate lading. If the intended 
lading would present an increased safety hazard during the test 
procedure (such as the use of poisonous or flammable gas), the cylinder 
may be charged with a typical liquefied or non-liquefied gas. Gases 
with essentially similar physical properties may be classified as 
typical.
    <bullet> Added the Bonfire Test Method to the publication. This 
permitted the Board of Explosives (BOE) test method to be used to 
qualify pressure relief device systems. The Bonfire Test Method was 
successfully used to qualify pressure relief device systems for 
decades.
    <bullet> Clarified what information is to be recorded before and 
during the actual test.
    <bullet> Increased the water capacity of a cylinder that can be 
fire tested from 500 pounds water capacity to 1000 pounds water 
capacity to permit a test method for all DOT 4-series cylinders.
    Worthington Cylinder and CGA submitted comments supporting the 
adoption of CGA C-14-2005, Reaffirmed 2010. Therefore, in this final 
rule, PHMSA is adopting CGA C-14-2005, Reaffirmed 2010 as proposed.

P-1630

    CGA submitted P-1630 requesting that PHMSA revise the HMR 
requirements for DOT 4L welded insulated cylinders. Specifically, the 
CGA requested PHMSA make two changes to add a definition of 
``recondition'' to Sec.  180.203 and amend paragraphs Sec. Sec.  
180.211(c) and 180.211(e) to clarify when a hydrostatic test must be 
performed on the inner containment vessel after the DOT 4L welded 
insulated cylinder has undergone repair.
    CGA submitted a comment to the NPRM requesting that we take no 
action on their petition. We received no other comments to the proposed 
changes based on P-1630, and therefore, we see no need to revise the 
HMR based on this petition and will not adopt any changes proposed by 
P-1630.

V. Special Permits and Comments Received

    This final rule addresses one special permit. In the ANPRM, PHMSA 
considered proposing revisions to adopt certain special permits into 
the HMR. Specifically, PHMSA proposed changes based on DOT-SPs 12929, 
13318, and 13599. In the NPRM, PHMSA did not propose changes in 
association with these special permits because: (1) DOT-SP 12929 was 
determined not suitable for adoption under rulemaking HM-233F (80 FR 
5340; January 30, 2015); and (2) DOT-SPs 13318 and 13599 were adopted 
under HM-233F (81 FR 3635; January 21, 2016).
    In the NPRM, we proposed to adopt provisions from DOT-SP 14237 to 
allow for the transportation of adsorbed gases in DOT specification 
cylinders by creating a new section, Sec.  173.302d, in the HMR. The 
HMR currently only authorizes the transportation of adsorbed gases in 
UN pressure receptacles under the provisions of Sec.  173.302c. The use 
of DOT cylinders containing adsorbed gases is currently authorized 
under various special permits. In the NPRM, we proposed to authorize 
the transportation of adsorbed gases in DOT-3E1800, DOT-3AA2015, and 
DOT-3AA2265 cylinders with a capacity between 0.4 and 7.3 liters. 
Additionally, the proposed Sec.  173.302d included a requirement to 
place the DOT specification cylinder into a non-DOT specification full-
opening, hinged-head or fully removable head, steel overpack cylinder 
constructed to meet the requirements of ASME Code Section VIII, 
Division 1 with a minimum design margin of 4 to 1.\9\
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    \9\ These are all provisions carried over from DOT-SP 14237.
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    We received several comments regarding this proposal. Praxair 
submitted a comment requesting that, rather than adopting DOT-SP 14237, 
we harmonize DOT cylinder adsorbed gas requirements with UN pressure 
receptacle requirements found in Sec.  173.302c, authorize all gases 
for use as adsorbed service instead of the ``short list'' proposed in 
Sec.  173.302d, eliminate the proposed overpack cylinder requirement, 
and, if we did not eliminate the overpack requirement, require the 
overpack be tested in a DOT-approved facility subject to the 
requirements of part 107, subpart I. CGA submitted a comment suggesting 
that rather than adopt the proposed special permit, we should align the 
proposed requirements for adsorbed gases in DOT cylinders in Sec.  
173.302d with the existing requirements for adsorbed gases in UN 
pressure receptacles currently found in Sec.  173.302c. COSTHA 
submitted a comment supporting the adoption of requirements for 
adsorbed gases in DOT cylinders, but noted that some of the gas entries 
we listed in the

[[Page 85403]]

proposed table in Sec.  173.302d had separate UN ID numbers for their 
adsorbed version in the Sec.  172.101 Hazardous Materials Table that 
should be cited instead of the non-adsorbed gas entry.
    Entegris submitted a comment requesting that rather than adopting 
DOT-SP 14237, we should adopt DOT SP-16485, which allows for 
transportation of adsorbed gases in DOT-3AA and DOT-3E cylinders in a 
manner harmonized with the current requirements for UN pressure 
receptacles in Sec.  173.302c. Entegris noted that the overpack 
requirement in DOT-SP 14237 was created to address the unique risks 
associated with transportation by aircraft, and presents a significant 
obstacle to efficient transportation by other modes. They noted that 
Sec.  173.302c does not require the use of overpacks for UN pressure 
receptacles containing adsorbed gas, nor does DOT-SP 16485.
    PHMSA response. We appreciate the comments we received on this 
topic. In this final rule, we are not adopting DOT-SP 14237, nor are we 
inserting requirements for adsorbed gases in DOT specification 
cylinders into the HMR in Sec.  173.302c. PHMSA's decision is based on 
the lack of consensus on this subject and technical concerns we have 
surrounding the modal requirements, minimum test pressure criteria, and 
authorized requalification. There are multiple existing DOT SPs that 
authorize the transportation of adsorbed gases in DOT specification 
cylinders. These permits authorize different adsorbed gases and utilize 
different DOT specification cylinders to contain the substrate and 
adsorbed gas, and have different operational controls. Incorporating 
the provisions of multiple special permits that authorize different 
materials, multiple specification and non-specification cylinders, and 
have differing operational controls, is challenging for PHMSA to 
attempt at the final rule stage without soliciting comments on the 
regulatory solution that melds the provisions and conditions of 
multiple permits together. The incorporation of adsorbed gases presents 
additional difficulties due to the risks presented by the highly toxic 
nature of the gases currently transported in adsorbed form, leading us 
to proceed with caution in adopting a standard into the HMR.
    Therefore, PHMSA believes that the most appropriate way to 
authorize adsorbed gases in DOT specification cylinders in the HMR is 
to conduct a more thorough review of existing systems authorized by 
special permit and propose a solution in a separate rulemaking, rather 
than risk creating imperfect regulatory requirements. We will further 
evaluate international standards for adsorbed gas transportation and 
existing DOT special permits for determination on how best to adopt 
provisions for adsorbed gases in DOT specification cylinders into the 
HMR. Adsorbed gases may continue to be transported in UN pressure 
receptacles in accordance with existing instructions in Sec.  173.302c, 
or in DOT cylinders under the terms of a special permit. We will 
consider revisiting this issue in a future rulemaking.

VI. Agency Initiated Editorial Corrections

    PHMSA regularly reviews and revises the HMR to correct errors and 
clarify any regulations that are unclear or confusing. PHMSA is making 
the following changes in this final rule.

Section 107.803

    Section 107.803 provides approval procedures for independent 
inspection agencies (IIA) conducting cylinder inspections and 
verifications as required by parts 178 and 180. In its application for 
approval status, the IIA must provide information, including a detailed 
description of its qualifications and ability both to perform and 
verify inspections. However, at present, the application information 
requirements of Sec.  107.803(c)(3) only reference part 178. In the 
NPRM, PHMSA proposed to revise Sec.  107.803(c)(3) to include part 180, 
subpart C, for consistency.
    We received one comment on this topic. Bancroft Hinchey supports 
this revision. Therefore, in this final rule are adopting this change 
as proposed in the NPRM.

Section 107.805

    Section 107.805 provides approval procedures for persons to 
inspect, test, certify, repair, or rebuild a cylinder in accordance 
with the HMR. PHMSA is revising the requirements for application for 
approval of cylinder requalifiers to include a reference to the option 
of having a mobile cylinder requalification unit (i.e., a mobile unit). 
See Sec.  180.203 for further discussion.
    We received one comment on this topic. Bancroft Hinchey supports 
this revision. Therefore, in this final rule we are adopting this 
change as proposed in the NPRM.

Section 178.70

    Section 178.70 provides approval for the manufacture of UN pressure 
receptacles (i.e., cylinders). Currently, Sec.  178.70(d) restricts the 
user (manufacturer) from the flexibility that is provided in the UN/ISO 
standards. The regulation as constructed results in additional cost and 
delay without any added safety. The UN/ISO standards are developed 
based on performance testing and include adequate testing for a wide 
range of design-type modifications. All UN/ISO standards to which the 
original design type conforms permit certain modifications to an 
approved design type. PHMSA has received several requests to revise 
this regulation to allow an authorized manufacturer to benefit from the 
UN Model Regulations and produce UN/ISO cylinders. In the NPRM, PHMSA 
proposed to adopt language consistent with UN/ISO standards to reduce 
the need for approvals.
    We received one comment on this topic. Bancroft Hinchey supports 
this revision. Therefore, in this final rule we are adopting this 
change as proposed in the NPRM.

Section 180.203

    Section 180.203 specifies definitions that apply to cylinder use, 
qualification, and maintenance. In the NPRM, PHMSA proposed two 
revisions to definitions in Sec.  180.203. In this final rule, we are 
adopting the definition for ``mobile unit'' with modifications based on 
comments received, and we are not adopting a new definition for ``proof 
pressure test.''
(1) Define and Adopt ``Mobile Unit'' Requalification Operations
    The hazardous materials program procedures of 49 CFR part 107 for 
approval of cylinder requalifiers do not specify the option of a 
``mobile cylinder requalification unit.'' The intent of this type of 
approval is to allow a cylinder requalifier to perform its requalifying 
function away from the primary place of business to better serve 
cylinder owners who need requalification testing and inspection of 
cylinders. In the NPRM, we proposed to limit the operations of a mobile 
unit to a 100-mile radius from the primary place of business. Eleven 
commenters objected to this limit based on economic, safety, and 
fairness grounds.
    PHMSA response. PHMSA will not place a distance limit on the 
operations of a mobile unit. However, an applicant for a mobile 
requalifier identification number (RIN) must specify the geographic 
area(s) in which they are requesting approval to operate. The 
requirement to provide geographic information on the operating range of 
a mobile unit is a part of the current approval process for mobile 
units. However, it is not codified in the language of Part 107 for 
cylinder

[[Page 85404]]

requalification approvals. The intent of this final rule is to codify 
the geographic information requirement in the text of part 107 to 
increase clarity, not create a new requirement. A mobile cylinder 
requalifier must adhere to the requirements in a PHMSA-issued approval 
letter to operate. Note that a mobile unit owned or operated by a 
previously approved requalifier must still receive a separate approval.
(2) Revise Definition of Proof Pressure Test for Cylinders
    The HMR no longer prescribe modified hydrostatic pressure testing, 
which has been and continues to be the method of low-pressure testing 
of fire extinguishers.\10\ In the NPRM, we proposed to modify the 
definition of ``proof pressure test'' to indicate that it could be 
performed with either liquid or a gas. We received 9 comments opposed 
to this change, and no comments in support.
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    \10\ PHMSA removed this from the HMR under HM-220D (67 FR 
51626).
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    Our description of the advantages of pneumatic, or gas-based, proof 
pressure testing in the NPRM was not entirely correct. In certain 
instances, pneumatic testing may not be faster, less expensive, less 
corrosive to the cylinder, or less environmentally harmful than 
hydrostatic testing. Pressurizing a cylinder to test pressure and then 
de-pressurizing it with air or another gas may take significantly 
longer than using water. Regarding corrosion concerns, use of 
compressed air for a pneumatic proof pressure test will generally 
introduce water into the cylinder, and use of dry gases would generally 
be cost-prohibitive except in very limited circumstances. Regarding 
environmental concerns, as several commenters noted, many cylinder 
requalifiers recycle the water they use.
    PHMSA response. When we removed the modified hydrostatic pressure 
test from the HMR and added the proof pressure test into part 180, we 
intended that the test be conducted with a liquid, except in special 
circumstances subject to a special permit. We do not believe that a 
general authorization for pneumatic proof pressure tests for cylinder 
requalification is in the public interest. Companies requesting 
authorization to perform pneumatic proof pressure tests for cylinder 
requalification may request special permits that detail the methods put 
in place to prevent death and serious injury in the event of a cylinder 
rupture at test pressure (i.e., much more energy is needed to 
pressurize a cylinder with a gas than liquid, thus presenting a safety 
risk to persons performing the test should a rupture occur). Therefore, 
we will not adopt the proposed modified definition of a proof pressure 
test in Sec.  180.203. Rather, we will modify the definition of the 
test based on comments to indicate clearly that the test is to be 
conducted with a liquid medium, unless otherwise authorized by a 
special permit.

Section 180.207

    Section 180.207(d) authorizes the use of ISO 6406 to requalify UN 
refillable seamless steel cylinders and UN refillable seamless steel 
tube cylinders. The current ISO 6406 has a limitation of 150 liters for 
the size of these cylinders, which is substantially less than the 
maximum volume of a UN refillable seamless steel tube (3,000 liters). 
Pressure tests and ultrasonic examination are authorized for UN 
cylinders with tensile strength below 950 MPa, and only ultrasonic 
examination is authorized for UN cylinders with a tensile strength 
greater than or equal to 950 MPa. PHMSA has received several requests 
for interpretation of this regulation and its application to the 
requalification of UN seamless steel pressure receptacles larger than 
150 liters. PHMSA responded to these requests through a letter of 
clarification issued under Reference No. 13-0146, stating that Sec.  
180.207(d)(1) authorizes the requalification of seamless steel UN 
pressure receptacles larger than 150 liters.
    We received two comments on this topic. Bancroft Hinchey supports 
the revision to include the phrase ``larger than 150 liters.'' FIBA 
submitted a comment requesting that we delete the reference to MEGCs 
from Sec.  180.207(d) because pressure receptacles exceeding 150 liters 
(e.g. UN refillable seamless steel tubes) may be used for the 
transportation of hazardous materials not only in MEGCs, but also in 
other bulk packages, such as a tube trailer motor vehicle.
    PHMSA response. We agree with FIBA that UN seamless steel cylinders 
larger than 150 liters may be found in other packaging configurations 
besides MEGCs. Our intent is to clarify that all UN seamless steel 
cylinders, regardless of size or service must be requalified in 
accordance with ISO 6406. However, we believe there is value in 
referencing MEGCs as an example of a scenario where users, fillers, or 
requalifiers may encounter these larger UN cylinders. Therefore, in 
this final rule we will amend the proposed Sec.  180.207(d)(1) to 
indicate that all UN seamless steel pressure receptacles, including 
those with a capacity over 150 liters, must be requalified in 
accordance with ISO 6406 whether installed in a MEGC or used in other 
service.

Section 180.213

    Section 180.213 prescribes marking requirements for the visual 
inspection of cylinders (see 49 CFR 180.213(f)(5), (8), and (9)). In 
the past, PHMSA has allowed a visual (V) requalifier identification 
number (``V-number'' or ``VIN'') to be marked in the same manner as a 
requalifier identification number (RIN) marking per Sec.  180.213. V-
number markings have four different options for markings. PHMSA issues 
approval letters that permit a V number marking, but only provide for 
three of the four available marking options and do not reference Sec.  
180.213.
    Including all the marking requirements for V-numbers into Sec.  
180.213 will make authorized options for these identification numbers 
to be placed on a cylinder more widely understood.
    Amerigas noted that when we inserted examples of acceptable ways to 
mark a VIN, we omitted one acceptable marking combination that is found 
in the VIN approval document. Bancroft Hinchey submitted a comment 
supporting inserting VIN marking examples into the HMR.
    PHMSA response. We agree with Amerigas, and will add the additional 
method that shows the month and year directly above the VIN. In this 
final rule, PHMSA is amending Sec.  180.213(g) to include examples of 
V-number markings, as proposed, as well as the method showing the month 
and year directly above the VIN.

Section 180.215

    Section 180.215(a)(6) requires that a person who requalifies, 
repairs, or rebuilds cylinders must maintain in their records and 
report information contained in each applicable CGA or ASTM standard 
incorporated by reference under Sec.  171.7 of the HMR that applies to 
requalifier activities. In the NPRM, PHMSA proposed to remove the last 
sentence of paragraph (a)(6) of this section to reduce confusion, as it 
essentially repeats what is requested in the first sentence of this 
paragraph.
    We received one comment on this topic. Bancroft Hinchey submitted a 
comment supporting this change. Therefore, in this final rule we will 
adopt it as proposed. COSTHA submitted a comment requesting that PHMSA 
revise the language in Sec.  180.215(c)(2)(vii) to delete the phrase 
``(permanent expansion may not exceed ten percent (10 percent) of total

[[Page 85405]]

expansion)'' because this requirement does not apply to all cylinders. 
We note the comment but consider it beyond the scope of this 
rulemaking. We will consider the topic for possible inclusion in a 
future rulemaking.

VII. Section-by-Section Review

Section 107.803

    Section 107.803(c)(3) states that each application to obtain 
approval to perform duties as an IIA must contain a detailed 
description of the applicant's qualifications and ability both to 
perform the inspections and to verify the inspections required by part 
178 of the HMR or under the terms of a DOT special permit. In this 
final rule, we revise Sec.  107.803(c)(3) as proposed to clarify that 
the applicant's description of his or her ability to perform and verify 
inspections must include those required under part 180 as well, 
consistent with the general requirements in paragraph (a) that refer to 
part 180.

Section 107.805

    Section 107.805(c) prescribes additional information an application 
must contain to obtain approval from PHMSA to requalify cylinders and 
pressure receptacles. In this final rule, we are adding paragraph 
(c)(5) as proposed to this section to clarify what information must be 
added to the application to authorize mobile unit requalifiers and the 
information necessary to acquire approval. We also make a conforming 
edit to paragraphs (c)(3) and (4) by moving the ``and'' clause from 
paragraph (c)(3) to paragraph (c)(4).

Section 171.7

    Section 171.7 lists reference standards incorporated by reference 
into the HMR that are not specifically set forth in the HMR.
    Paragraph (n) specifically incorporates into the HMR publications 
issued by the CGA, an industrial and medical gas association that, 
among others, develops standards and practices for the safe 
transportation of gases and their containers. In this final rule, we 
add the Eleventh edition (2016) of CGA publication C-1, Methods for 
Pressure Testing Compressed Gas Cylinders to Sec.  171.7(n). We also 
update the editions of CGA publications C-3, C-6, C-14, and S-1.1 
already incorporated in the HMR. The remaining changes to paragraph (n) 
are editorial based on PHMSA's initiative to renumber the list to 
accommodate the new publications and add missing section number 
symbols, punctuation, and spaces. The documents are summarized below.
    The CGA publications include the following:
    (1) CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders 
(2016; Eleventh edition). This publication provides the standard(s) for 
pressure testing of compressed gas cylinders for many newly 
manufactured cylinders and requalification of cylinders. This standard 
contains operating and equipment requirements necessary to perform 
pressure testing of compressed gas cylinders properly. Tests include 
the water jacket method, direct expansion method, and proof pressure 
method.
    (2) CGA C-3, Standards for Welding on Thin-Walled Steel Cylinders 
(2005, Reaffirmed 2011; Seventh edition). This publication contains 
information on welding process qualification, welding operator 
qualifications, tensile testing, bend testing, and radiographic 
inspection. Additionally, this publication clarifies dimensional 
tolerances and when weld macro etch can be used for weld process 
approval and welder qualification approval.
    (3) CGA C-6, Standards for Visual Inspection of Steel Compressed 
Gas Cylinders (2013; Eleventh edition). This publication provides 
cylinder users (requalifiers, owners, fillers, operators, etc.) with 
criteria to accept, reject, and condemn steel compressed gas cylinders. 
This standard does not cover all circumstances for each individual 
cylinder type and condition of lading. Inspection procedures include 
preparation of cylinders for inspection; exterior inspection; interior 
inspection (if required); nature and extent of damage to be looked for; 
and for some tests, the conditions of the cylinder, etc. A sample 
inspection report is provided in an appendix.
    (4) CGA C-14, Procedures for Fire Testing of DOT Cylinder Pressure 
Relief Device Systems (2005, Reaffirmed 2010; Fourth edition). This 
publication describes test procedures and apparatus for fire testing 
compressed gas cylinder safety (pressure) relief devices as required by 
the HMR. The procedures are applicable for cylinders that have less 
than 500 lbs. water capacity and designed to provide a means of testing 
to the HMR anywhere with reliable test data and repeatable test 
results.
    (5) CGA S-1.1, Pressure Relief Device Standards--Part 1--Cylinders 
for Compressed Gases (2011; Fourteenth edition). This publication 
provides the standard(s) for selection of the correct pressure relief 
device that is required to meet the requirements of the HMR for over 
150 gases. It provides guidance on when a pressure relief device can be 
optionally omitted, and when the use of a pressure relief device is 
prohibited. It provides direction and guidance on the manufacture and 
testing of pressure relief devices as well as the operation parameters 
and maintenance. In this final rule, we are removing the phrase ``with 
the exception of paragraph 9.1.1'' from Sec.  171.7(n)(18). Compliance 
with paragraph 9.1.1 is still not required; however, we have moved this 
instruction to each place S-1.1 is incorporated in Part 173 and Part 
178 for clarity.
    All of these CGA standards are available for purchase on the CGA 
website.\11\ Additionally, these standards are available for public 
inspection at the Hazardous Material Information Center ((202) 366-
4488; <a href="/cdn-cgi/l/email-protection#bed7d0d8d1ddd0caccfedad1ca90d9d1c8"><span class="__cf_email__" data-cfemail="b6dfd8d0d9d5d8c2c4f6d2d9c298d1d9c0">[email protected]</span></a>) by appointment.
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    \11\ https://www.cganet.com/what-we-do/standards-publications/.
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    The regulatory text of this rule references ASTM E 8-99, The 
Aluminum Association's ``Welding Aluminum: Theory and Practice, Fourth 
Edition, 2002'', and Transport Canada's TDG Regulations. These 
standards are already approved for the sections that are being amended.

Section 171.23

    Section 171.23 prescribes requirements for transport of specific 
materials and packaging under international transportation standards 
such as the International Civil Aviation Organization Technical 
Instructions for the Safe Transport of Dangerous Goods by Air. 
Paragraph (a)(5) outlines requirements for filling of cylinders for 
export or use onboard a vessel. In this final rule, we revise the 
marking requirements consistent with changes made to Sec.  180.213.

Section 173.3

    Section 173.3(d)(1) prescribes how a damaged or leaking cylinder 
that contains hazardous material may be transported in a non-DOT-
specification fully opening hinged-head or removable head steel salvage 
cylinder. In this final rule, we are amending Sec.  173.3(d)(1) to 
permit cylinders that contain Class 4 or 5 materials to use this 
exception as well. In addition, because of the inclusion of Class 4 or 
5 materials as authorized material for salvage cylinders, we are 
reformatting the regulatory text to reference those materials in 
damaged or leaked cylinders that are excluded from being allowed to be 
overpacked in a salvage cylinder rather than listing those that are 
authorized.

[[Page 85406]]

Section 173.301

    Section 173.301 provides the general requirements for shipment of 
compressed gases and other hazardous material in cylinders. In this 
final rule in paragraphs (c) and (f), we make an editorial revision to 
correct the section citation of CGA S-1.1 to read 9.1.1. Additionally, 
we are revising paragraph (f) to clarify the pressure relief 
requirements for DOT 39 cylinders. See the discussion of P-1580 for 
further details.

Section 173.302

    Section 173.302(f) prescribes the requirements for transporting 
non-liquefied or ``permanent'' oxidizing gases by air. We are amending 
Sec.  173.302(f)(2)(i) and adding a new Sec.  173.302(f)(2)(iii) to 
align with CGA S-1.1 requirements for DOT 39 cylinders. See the 
discussion of P-1580 for further details.

Section 173.302a

    Section 173.302a(a)(3) prescribes the filling requirements for DOT 
39 cylinders that contain Division 2.1 gas or chemical under pressure. 
In the NPRM, we proposed to clarify the capacity (internal volume) 
requirements, to make it clear that the 1.23 liter limit applies to 
Division 2.1 material, and specification size limits of a DOT 39 
cylinder apply to chemicals under pressure classed as Division 2.1 (see 
49 CFR 172.102, special provision 362). As we noted in the NPRM, the 
previous 50 L limit for chemical under pressure in a DOT 39 cylinder is 
much larger than the actual maximum size authorized for the DOT 39 
specification in Sec.  178.65. This discrepancy was an unintentional 
outcome of a harmonization effort with international requirements for 
non-refillable cylinders, which allow larger sizes than the HMR (see 
Docket No. PHMSA-2012-0027 (HM-215L); 78 FR 988). To reduce confusion 
introduced by the conflict of the 50 L quantity in Sec.  173.302a(a)(3) 
and the capacity limts of the specification, we are deleting the 
reference to ``50 L (3050 in\3\)'' and replacing it with reference to 
the DOT 39 specification capacity limits--1526 in\3\ for a service 
pressure of 500 psig or less, and 277 in\3\ for a service pressure of 
greater than 500 psig.
    We also proposed an editorial correction to the start of paragraph 
(a)(3) by removing the non-italicized ``DOT 39.''
    Section 173.302a(c) provides special filling limits for DOT 3A, 
3AX, 3AA, and 3AAX cylinders filled with hydrogen and mixtures of 
hydrogen with helium, argon, or nitrogen. We are modifying Sec.  
173.302a(c)(4) to harmonize with CGA S-1.1. Shippers are not required 
to install pressure relief devices on tubes (cylinders longer than 144 
inches, or 12 feet) shipped in accordance with this paragraph, however 
their continued use and installation is authorized. This change 
maintains regulatory flexibility and alignment with accepted industry 
practice. See discussion of P-1592 for further details.

Section 173.304

    Section 173.304(f) prescribes the requirements for transporting 
liquefied compressed oxidizing gases by air. In this final rule, we are 
amending Sec.  173.304(f)(2)(i) and adding a new Sec.  
173.304(f)(2)(iii) to align with CGA S-1.1 pressure relieve device 
requirements for DOT 39 cylinders. See the discussion of P-1580 for 
further details.

Section 173.304a

    Section 173.304a prescribes the maximum permitted filling density 
and authorized cylinders for specific gases. In the NPRM, we proposed 
to add new paragraph (a)(3) to Sec.  173.304a to state clearly that the 
maximum capacity (internal volume) of a DOT 39 cylinder containing 
liquefied flammable gas is 1.23 liters (75 in\3\). We also proposed to 
require these cylinders to be equipped with a pressure relief valve, as 
prescribed in CGA S-1.1, unless the material is not listed in CGA S-
1.1, in which case a CG-7 pressure relief valve must be used.
    In this final rule we are modifying our proposed change to Sec.  
173.304a and imposing a 75 in\3\ limit on the capacity of DOT 39 
cylinders containing the following liquefied flammable gases: 
Cyclopropane, ethane, ethylene, and liquefied petroleum gas. We are 
also adopting the requirement that a DOT 39 cylinder containing a 
liquefied gas not listed by name in CGA S-1.1 must be equipped with a 
CG-7 pressure relief valve, as proposed. See discussion of P-1622 for 
further details.

Section 173.306

    Section 173.306 provides exceptions from the requirements of the 
HMR for limited quantities of compressed gas. Paragraph (g) excepts 
water pump system tanks charged with compressed air or limited 
quantities of nitrogen to not over 40 psig from labeling and 
specification packaging when shipped in conformance with the 
requirements prescribed in the paragraph. In this final rule, we revise 
Sec.  173.306(g) to authorize composite as well as steel tanks, to 
require a more flexible testing regime at the manufacturers MAWP rather 
than a set 100 psig, to allow water pump system tanks to be charged 
with helium, and to clarify that transportation by aircraft is not an 
authorized mode of transport. See discussion of P-1582 for more 
details.

Section 173.309

    In the NPRM, we proposed to revise Sec.  173.309 to state that the 
requirements applicable to fire extinguishers also apply to those 
cylinders used as part of a fire suppression system. In this final 
rule, we are adopting the change as proposed, while clarifying our 
intent as to what is considered a ``fire extinguisher.'' We are 
allowing cylinders charged with a compressed gas and an extinguishing 
agent that are intended for installation into fire suppression systems 
to be described as ``UN1044, Fire extinguishers.'' We are not allowing 
cylinders charged with an inert gas and used only to pressurize a fire 
suppression system to be described as ``UN1044, Fire extinguishers'' 
when offered for transportation separately from the suppression system. 
See discussion of P-1546 for further details.

Section 173.312

    Section 173.312(b)(1) prescribes the filling requirements for 
multiple element gas containers (MEGCs). In this this final rule, we 
are clarifying requirements for filling MEGC pressure receptacles 
containing liquefied compressed gas by weight to emphasize that each 
pressure receptacle must be filled individually. See discussion of P-
1572 for further details.

Section 173.323

    Section 173.323 is the packaging section for ethylene oxide. In 
this final rule, we are making an editorial revision to this section to 
add a reference to the central IBR section, Sec.  171.7, for the 
existing references to CGA Pamphlet C-14. CGA C-14 was previously 
approved for inclusion in this section, but through an oversight, Sec.  
171.7 was not referenced as required for approved IBRs. This final rule 
corrects that oversight.

Section 178.35

    Section 178.35(f) prescribes the marking requirements that apply to 
DOT-specification cylinders. In this final rule, we are adding new 
paragraph (f)(8) to Sec.  178.35 to require that cylinder tare weight 
or mass weight, and water capacity be marked on certain DOT-
specification cylinders that are filled by weight. See discussion of P-
1540 for further details.
    Although we did not discuss the above in the petition discussion 
section,

[[Page 85407]]

we note Dow Chemical submitted a comment requesting that we add a 
paragraph to Sec.  178.35 stating that a cylinder manufactured under 
this subpart prior to publication of HM-234 may continue to be filled 
and offered for transportation until its authorized service life has 
expired. We do not believe such a statement is necessary. Section 
173.301(a)(1) addresses this situation by providing that compressed 
gases must be in UN pressure receptacles built in accordance with the 
UN standards or in metal cylinders and containers built in accordance 
with the DOT and ICC specifications and part 178 in effect at the time 
of manufacture or CRC, BTC, CTC or TC specification, and requalified 
and marked as prescribed in subpart C in part 180, if applicable.
    Cylinders manufactured prior to the publication of HM-234 may 
continue in service, subject to the requalification provisions of part 
180, subpart C, and other applicable requirements of the subchapter.

Sections 178.36, 178.37, 178.38, 178.39, 178.42, 178.44, 178.45, 
178.46, 178.47, 178.50, 178.51, 178.53, 178.55 178.56, 178.57, 178.58, 
178.59, 178.60, 178.61, 178.65, and 178.68

    These sections prescribe the DOT-specification requirements for a 
cylinder type including the performance standards for pressure testing 
of the cylinder. In this final rule, we require that testing and 
equipment used to conduct the pressure testing be in conformance with 
CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders, to 
provide for consistency and clarity in performance of pressure testing. 
In this final rule, we also revise the format of the pressure testing 
paragraphs for greater consistency, including adding notification that 
any pressurization in excess of 90% of test pressure constitutes a 
test, and that operator error (i.e. selecting the wrong test pressure) 
is an acceptable reason to allow a repeated test in accordance with CGA 
C-1 requirements. See the discussions of P-1515 and P-1626 for further 
details on the requirements in CGA C-1. A detailed discussion of 
changes to each section follows.

Section 178.36 Specification 3A and 3AX Seamless Steel Cylinders

    The paragraph (i) title ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into (i)(1) and (3) 
for volumetric expansion testing as proposed.

Section 178.37 Specification 3AA and 3AAX Seamless Steel Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(i)(1) and (3) for volumetric expansion testing as proposed.

Section 178.38 Specification 3B Seamless Steel Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(i)(1) and (3) for volumetric expansion testing as proposed. To 
increase clarity, in this final rule we move the instructions for proof 
pressure testing of cylinders after a selected cylinder from a lot is 
volumetrically expansion tested at 3 times service pressure from the 
proposed paragraph (i)(5) to paragraph (i)(2)(ii) to ensure cylinder 
manufactures are aware of the requirement when reading through 
paragraph (i). As a result, we also incorporate CGA C-1 into paragraph 
(i)(2) for proof pressure testing.

Section 178.39 Specification 3BN Seamless Nickel Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(i)(1) and (3) as proposed.

Section 178.42 Specification 3E Seamless Steel Cylinders

    The paragraph (f) ``Hydrostatic test'' is renamed ``Pressure 
testing'' as proposed. As discussed in our discussion of P-1626 we are 
not adopting the proposed re-organization of Sec.  178.42(f) based on 
comments received that the new layout would generate confusion for 
regulated entities. Further, CGA C-1 is incorporated by reference for 
burst testing in paragraph (f)(2) and proof pressure testing in 
paragraph (f)(3).

Section 178.44 Specification 3HT Seamless Steel Cylinders for Aircraft 
Use

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(i)(1) and (3) for volumetric expansion testing as proposed.

Section 178.45 Specification 3T Seamless Steel Cylinder

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(i)(1) and (3) for volumetric expansion testing as proposed.

Section 178.46 Specification 3AL Seamless Aluminum Cylinders

    The paragraph (g) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(g)(1) and (3) for volumetric expansion testing as proposed. The HMR 
currently only allows one repeat test for 3AL cylinders in the case of 
equipment failure. As proposed, we maintain this requirement in this 
final rule. 3AL cylinders may only be subjected to one repeat test, 
rather than the two allowed under CGA C-1. This is due to the different 
expansion properties of aluminum compared to steel, which would render 
the expansion measured during a 2nd repeated test at increased pressure 
an invalid measurement of the cylinder's suitability.

Section 178.47 Specification 4DS Welded Stainless Steel Cylinders for 
Aircraft Use

    The paragraph (j) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference into paragraphs 
(j)(1) and (3) for volumetric expansion testing as proposed. As 
proposed, the final rule adds an option for direct expansion testing 
for 4DS cylinders. PHMSA believes that including the hydrostatic 
testing direct expansion method in addition to the water jacket method 
provides for greater flexibility for the tester by allowing an 
alternative hydrostatic testing method for determining permanent 
expansion. PHMSA believes that direct expansion will provide an 
equivalent level of safety when performed in accordance with CGA C-1.

Section 178.50 Specification 4B Welded or Brazed Steel Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (i)(1) 
for volumetric expansion testing of one selected cylinder per lot, and 
(i)(2) for pressure testing the remainder of the lot as proposed.

Section 178.51 Specification 4BA Welded or Brazed Steel Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (i)(1) 
for volumetric expansion testing of one selected cylinder per lot, and 
paragraph (i)(2) for pressure testing the remainder of the lot as 
proposed.

[[Page 85408]]

Section 178.53 Specification 4D Welded Steel Cylinders for Aircraft Use

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure test'' 
and CGA C-1 is incorporated by reference as proposed. In this final 
rule, we are re-inserting the option to conduct a volumetric expansion 
test on each cylinder at 2 times service pressure. It was not our 
intent to remove this option for cylinder manufacturers.

Section 178.55 Specification 4B240ET Welded or Brazed Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (i)(1) 
for volumetric expansion testing, paragraph (i)(2) for pressure 
testing, and paragraph (i)(3) for burst testing as proposed.

Section 178.56 Specification 4AA480 Welded Steel Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (i)(1) 
for volumetric expansion testing and paragraph (i)(2) for pressure 
testing as proposed.

Section 178.57 Specification 4L Welded Insulated Cylinders

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraphs (i)(1) 
and (3) for pressure testing as proposed.

Section 178.58 Specification 4DA Welded Steel Cylinders for Aircraft 
Use

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraphs (i)(1) 
and (3) for volumetric expansion testing as proposed.

Section 178.59 Specification 8 Steel Cylinders With Porous Fillings for 
Acetylene

    The paragraph (h) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated in paragraph (h)(1) for 
volumetric expansion testing and paragraph (h)(2) for pressure testing 
as proposed. Additionally, we have editorially revised paragraph (h) to 
clarify that if the randomly selected cylinder from each lot fails the 
volumetric expansion test, the remaining cylinders in the lot are not 
eligible for proof pressure testing and each cylinder must pass a 
volumetric expansion test at 750 psig to be accepted.

Section 178.60 Specification 8AL Steel Cylinders With Porous Fillings 
for Acetylene

    The paragraph (j) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (j)(1) 
for volumetric expansion testing and paragraph (j)(2) for proof 
pressure testing as proposed. Additionally, we have editorially revised 
paragraph (j) to clarify that if the randomly selected cylinder from 
each lot fails the volumetric expansion test, the remaining cylinders 
in the lot are not eligible for proof pressure testing and must pass a 
volumetric expansion test at 750 psig to be accepted.

Section 178.61 Specification 4BW Welded Steel Cylinders With Electric-
Arc Welded Longitudinal Seam

    The paragraph (i) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (i)(1) 
for volumetric expansion testing and paragraph (i)(2) for pressure 
testing as proposed.

Section 178.65 Specification 39 Non-Reusable (Non-Refillable) Cylinders

    The paragraph (f) ``Pressure tests'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraph (f)(1) 
for proof pressure testing and paragraph (f)(2) for burst testing as 
proposed.

Section 178.68 Specification 4E Welded Aluminum Cylinders

    The paragraph (h) ``Hydrostatic test'' is renamed ``Pressure 
testing'' and CGA C-1 is incorporated by reference in paragraphs (h)(1) 
and (2) for volumetric expansion testing and paragraph (h)(3) for 
pressure testing as proposed.

Sections 178.50, 178.51, 178.61, and 178.68

    These sections prescribe DOT 4-series specification requirements. 
As written these specifications are at times unclear to manufacturers 
and enforcement personnel. In this final rule, we are revising the 
specification requirements to promote consistent and uniform 
manufacturing practices for DOT 4-series cylinders to improve 
understanding by these entities. See the discussion of P-1501 for 
further details. Below we will discuss changes to each section in 
detail.

Section 178.50 Specification 4B Welded or Brazed Steel Cylinders

    For steel requirements, we are requiring that manufacturers keep a 
record of intentionally added alloying elements, as proposed.
    For material identification, the final rule makes an editorial 
clarification that the method used to identify the material must not 
compromise the integrity of the cylinder, as proposed.
    For heat treatment, we are making an editorial clarification to 
direct cylinder manufacturers to table 1 to appendix A of part 178 for 
details on suitable heat treatment.
    For cylinder attachments, we have moved thread requirements to 
their own paragraph, (h)(h), without making any changes to thread 
requirements.
    For elongation requirements, we are allowing reduction in 
elongation percentage based on cylinder tensile strength to align with 
requirements for DOT 4BA and 4BW cylinder requirements.
    For rejected cylinders, we are adopting as proposed heat treatment 
after seam repairs requirements as follows:
    <bullet> For cylinders with an outside diameter of less than or 
equal to six (6) inches, welded seam repairs greater than one (1) inch 
in length shall require reheat treatment of the cylinder.
    <bullet> For cylinders greater than an outside diameter of 6 
inches, welded seam repairs greater than three (3) inches in length 
shall require reheat treatment.
    The HMR current manufacturing standards require heat treatment 
after any welding repair, but we believe this additional flexibility 
for manufacturers will maintain the same high level of safety for 
repaired cylinders.
    Finally, we are removing discussion of embossing the head or 
sidewall of the cylinder from Sec.  178.50(o)(2). PHMSA has concerns 
with defining ``embossing.'' Markings must be stamped plainly and 
permanently on the cylinder as prescribed in Sec.  178.50(o)(1).

Section 178.51 Specification 4BA Welded or Brazed Steel Cylinders

    For steel, we are requiring that manufacturers keep a record of 
intentionally added alloying elements, as proposed.
    For material identification, the final rule makes an editorial 
clarification that the method used to identify the material must not 
compromise the integrity of the cylinder, as proposed.
    For head attachment, we are allowing heads to be attached by 
welding, as proposed. The previous restriction to brazing only was not 
PHMSA's intent.
    For seams, we are making an editorial revision to paragraph (a) to 
clarify that longitudinal seams are permitted for cylindrical-type 
cylinders as proposed.

[[Page 85409]]

    For welding, we are making an editorial revision to paragraph (e), 
as proposed, to clarify allowable welding operations on the cylinder.
    For yield strengths, tensile strengths, elongations and reduction 
of area of material, we are re-naming paragraph (j) from ``Physical 
tests'' to ``Mechanical tests'' as proposed. Additionally, we are 
removing the language requiring that the mechanical tests be conducted 
on a cylinder that has passed the hydrostatic testing because the 
mechanical tests are unrelated to the pressure test requirements. 
During our review of the final rule, we noted we inadvertently omitted 
the requirement that mechanical tests must be conducted after heat 
treatment. This was not our intent; therefore, we are re-inserting the 
statement that mechanical tests must be conducted after heat treatment 
is performed.
    For mechanical test samples for spherical cylinders, we are now 
allowing samples to be taken directly from the formed sphere, if the 
manufacturer desires, in order ensure the mechanical test samples are 
as representative as possible of the spheres themselves.
    In this final rule, we require that manufacturers remove samples 
for mechanical tests as provided in appendix A to subpart C of part 178 
as proposed in order to improve consistency of cylinder mechanical 
tests. PHMSA believes that all manufacturers were previously removing 
samples as recommended in appendix A to subpart C of part 178, 
therefore this will not create any new burdens for industry.
    For rejected cylinders, we are adopting as proposed heat treatment 
after seam repairs requirements as follows:
    <bullet> For cylinders with an outside diameter of less than or 
equal to six (6) inches, welded seam repairs greater than one (1) inch 
in length shall require reheat treatment of the cylinder.
    <bullet> For cylinders greater than an outside diameter of 6 
inches, welded seam repairs greater than three (3) inches in length 
shall require reheat treatment.

The HMR current manufacturing standards require heat treatment after 
any welding repair, but we believe this additional flexibility for 
manufacturers will maintain the same high level of safety for repaired 
cylinders.
    Finally, we are removing discussion of embossing the head or 
sidewall of the cylinder from Sec.  178.51(n)(2). PHMSA has concerns 
with defining ``embossing.'' Markings must be stamped plainly and 
permanently on the cylinder as prescribed in Sec.  178.51(n)(1).

Section 178.61 Specification 4BW Welded Steel Cylinders With Electric-
Arc Welded Longitudinal Seam

    For steel, we are requiring that manufacturers keep a record of 
intentionally added alloying elements, as proposed.
    For identification of material, the final rule makes an editorial 
clarification that the method used to identify the material must not 
compromise the integrity of the cylinder, and that plates and billets 
for hotdrawn cylinders must be marked with the heat number, as 
proposed. PHMSA believes that cylinder manufacturers are already in 
compliance with this requirement and this does not impose any new 
burden on industry.
    For examination of welds, we are adding reference to radioscopic 
examination, when conducted in accordance with CGA C-3, to increase 
flexibility for manufacturers while not compromising examination of 
welds.
    For heat treatment, we are aligning the heat treatment requirements 
with those for DOT 4BA cylinders and clarifying that heat treatment may 
occur before, during, or after brazing operations.
    For yield strengths, tensile strengths, elongations and reduction 
of area of material, we are re-naming paragraph (j) from ``Physical 
tests'' to ``Mechanical tests'' and adding introductory text as 
proposed. This editorial change is intended to align the 4BW 
specification language with the similar DOT 4B and 4BA cylinders 
language. Additionally, we are requiring that manufacturers remove 
samples for mechanical tests as provided in appendix A to subpart C of 
part 178, as proposed, in order to improve consistency of cylinder 
mechanical tests. PHMSA believes that all manufacturers were previously 
removing samples as recommended in appendix A to subpart C of part 178, 
therefore this will not create any new burdens for industry. Finally, 
for the guided bend test we are aligning the DOT 4BW requirements with 
the 4BA and allowing specimens to be taken from welded test plates and 
additional specimen testing if the original specimen fails.
    For openings to cylinders, we are aligning the DOT 4BW requirements 
with the existing requirements for DOT 4B and 4BA cylinders as proposed 
to promote consistency and simplify compliance for manufacturers 
producing these similar cylinders. Additionally, we are aligning the 
4BW with the 4B specification by adding an allowance to attach brass 
fittings that are components of handheld fire extinguishers.
    For rejected cylinders, we are adopting as proposed heat treatment 
after seam repairs requirements as follows:
    <bullet> For cylinders with an outside diameter of less than or 
equal to six (6) inches, welded seam repairs greater than one (1) inch 
in length shall require reheat treatment of the cylinder.
    <bullet> For cylinders greater than an outside diameter of 6 
inches, welded seam repairs greater than three (3) inches in length 
shall require reheat treatment.
    The HMR current manufacturing standards require heat treatment 
after any welding repair, but we believe this additional flexibility 
for manufacturers will maintain the same high level of safety for 
repaired cylinders.
    For marking, we are adding the following marking locations:
    1. On side wall adjacent to top head for side walls not less than 
0.090 inch thick.
    2. On a cylindrical portion of the shell that extends beyond the 
recessed bottom of the cylinder constituting an integral and non-
pressure part of the cylinder.
    3. Neckring.

These new locations for the 4BW are already allowed for the very 
similar 4BA cylinder, are intended to align the 4BW with the 4BA with 
no decrease in safety.

    Finally, we are removing discussion of embossing the head or 
sidewall of the cylinder from Sec.  178.61(n)(2). PHMSA has concerns 
with defining ``embossing.'' Markings must be stamped plainly and 
permanently on the cylinder as prescribed in Sec.  178.61(n)(1).

Section 178.68 Specification 4E Welded Aluminum Cylinders

    For aluminum material in Sec.  178.68(b), we are requiring that 
manufacturers keep a record of intentionally added alloying elements, 
as proposed. Additionally, we are revising Note 1 to Table 1 to 
maintain the requirement to conduct regular analysis of the material. 
It was our intent for the requirement to record intentionally added 
alloying elements to complement the regular analysis of the material, 
not replace it.
    For yield strengths, tensile strengths, elongations and reduction 
of area of material, we are re-naming paragraph (j) from ``Physical 
tests'' to ``Mechanical tests'' as proposed. For acceptable results for 
mechanical tests we are not adding the phrase ``a minimum tensile 
strength as defined in paragraph (f)(1)(ii)

[[Page 85410]]

of this section'' to paragraph (k). This text is unnecessary, therefore 
we are not adopting it. For the alternate guided bend test, we are 
revising requirements to align with the standards of the Aluminum 
Association and similar low-pressure steel cylinders.
    Finally, we are removing discussion of embossing the head or 
sidewall of the cylinder from Sec.  178.68(n)(2). PHMSA has concerns 
with defining ``embossing.'' Markings must be stamped plainly and 
permanently on the cylinder as prescribed in Sec.  178.68(n)(1).

Section 178.70

    Section 178.70(d) prescribes the requirements to obtain design 
approval of a UN pressure receptacle. In this final rule, we are 
revising paragraph (d) as proposed to include language that an approval 
for a design modification is not required if the specific design 
modification is covered under the UN/ISO standard for the design type 
already approved.
    In our review of the NPRM, we discovered we inadvertently deleted 
the sentence ``An audit may be required as part of the process to 
modify an approval'' from Sec.  178.70(d). This was not our intent, 
therefore in this final rule we are reinserting this sentence.

Section 178.75

    Section 178.75 contains the requirements for construction of Multi-
Element Gas Containers (MEGCs). In this final rule, we are making two 
editorial revisions to Sec.  178.75. First, we are correcting a spacing 
error that made paragraphs (e)(3)(i) and (ii) appear to be part of the 
same paragraph. Additionally, we are clarifying that compliance with 
CGA S-1.1 paragraph 9.1.1 is not required for PRDs installed on MEGCs. 
This editorial change is necessary because we have removed the phrase 
``except 9.1.1'' from the central Sec.  171.7 IBR reference for CGA S-
1.1.

Section 180.203

    Section 180.203 prescribes definitions that apply to the 
qualification, maintenance, and use of cylinders under the HMR. In this 
final rule, we add new definitions for the terms or phrases ``mobile 
unit'' and ``over-pressurized,'' and revise the definitions for 
``commercially free of corrosive components'' and ``proof pressure 
test.'' We previously discussed the definitions for ``mobile unit'' and 
``proof pressure test'' in Section VII. Agency Initiated Editorial 
Corrections. The revision to ``commerically free of corrosive 
components'' is an editorial revision to express the allowable water 
content in parts per million (ppm) rather than dew point. We added a 
definition for ``over-pressurized'' because it is now included as a 
condition for condemnation of a cylinder under Sec.  180.205(i)--i.e., 
a cylinder that is known to have been or shows evidence of being 
``over-pressurized.'' We received no comments related to the new 
definition for ``over-pressurized'' and therefore will adopt as 
proposed. We delete the definitions for ``defect,'' ``elastic 
expansion,'' ``permanent expansion,'' ``rejected cylinder,'' ``test 
pressure,'' ``total expansion,'' ``visual inspection,'' and 
``volumetric expansion test.'' These new and revised definitions will 
clarify the cylinder requirements prescribed in part 180, subpart C. 
The deletion of definitions is intended to remove conflicts and 
redundancies with the newly incorporated by reference CGA C-1 
definitions. See discussion of P-1515 and P-1626 for further discussion 
of CGA C-1.

Section 180.205

    Section 180.205 prescribes the general requirements for 
requalifying DOT-specification cylinders. In this final rule, we are 
revising and adding new regulatory text for clarity, and incorporating 
CGA C-1 into the HMR. Specifically, we clarify the conditions requiring 
test and inspection of cylinders under paragraph (d) by including a 
reference to thermal damage as proposed by P-1515 (discussed above in 
Section IV) to identify cylinders weakened by exposure to heat and 
evidence of grinding; revise the paragraph (f) visual inspection 
requirements to include reference to shot blasting and ``chasing'' of 
cylinders as proposed by P-1515 in accordance with previous PHMSA 
guidance; revise the paragraph (g) requirements for pressure tests by 
incorporating by reference CGA C-1; editorially revise paragraph (h) to 
clarify that rejected cylinders must be repaired or rebuilt as provided 
in Sec.  180.211 prior to further use, not just requalified; revise 
paragraph (i) to clarify the responsibilities of the requalifier and 
add conditions under which a cylinder must be condemned, including arc 
burns on aluminium cylinders, known over-pressurization, end of service 
life, and stamping on sidewalls as proposed by P-1515; and move the 
reference of training materials to its own paragraph (j). See 
discussion of P-1515 and P-1626 for additional information on the 
incorporation of CGA C-1.

Section 180.207

    Section 180.207 prescribes requirements for requalifying UN 
pressure receptacles. In this final rule, we revise and add new 
regulatory text for clarity. In the NPRM, we proposed to remove 
language authorizing approvals for the extension of the service life of 
a composite ISO pressure receptacle and require condemnation in 
accordance with Sec.  180.205(i)(1)(x). In this final rule, we will not 
adopt these changes, but we will remove reference to a 15-year service 
life because it does not apply to all ISO composite cylinders. Approval 
may still be sought to extend the life of ISO composite pressure 
receptacles and each request will be considered on a case by case 
basis. Additionally, we clarify language in the introduction to the 
requalification table to confirm that UN pressure receptacles must be 
requalified prior to filling the cylinders beyond the marked 
requalification date; editorially revise paragraph (d) for clarity; and 
revise the requalification procedures for seamless steel cylinders to 
include MEGC and other pressure receptacles larger than 150 liters 
water capacity.

Section 180.209

    Section 180.209 prescribes requirements for requalifying 
specification cylinders. In this final rule, we are revising and adding 
new regulatory text for clarity and incorporating by reference the 2016 
version of CGA C-1, Methods for Pressure Testing Compressed Gas 
Cylinders. Specifically, we revise: The requirement for a hammer test 
in Sec.  180.209(b); the paragraph (c) tare weight marking 
requirements; the paragraph (e) proof pressure testing requirements to 
incorporate by reference CGA C-1; the paragraph (g) visual inspection 
requirements to remove the obsolete reference to a delayed compliance 
period that ended in 2004 and to create an entry for cylinders 
containing propylene, commercially free from corroding components to be 
requalified visually as proposed by P-1626; the paragraph (j) 
requirements for fire extinguisher requalification to align with CGA C-
1, including allowing direct expansion tests for 4-series cylinders 
used as fire extinguishers because we believe the direct expansion 
method is an equivalent method for requalifying fire extinguishers; and 
the paragraph (l) requirements for marking foreign cylinders. See 
discussion of P-1626 and P-1515 for additional information on the 
incorporation of CGA C-1 and additional editorial revisions to Sec.  
180.209.

Section 180.212

    Section 180.212(a) prescribes requirements to repair seamless DOT 
3-

[[Page 85411]]

series specification cylinders and seamless UN pressure receptacles. In 
this final rule, we are revising paragraph (a) to require an ultrasonic 
examination on DOT 3-series cylinders and seamless UN pressure 
receptacles after any grinding is performed on these cylinders. 
Additionally, we are adopting as proposed prohibitions from removing 
arc burns from cylinders. The presence of arc burns requires cylinder 
rejection at time of visual inspection, and repair facilities may not 
remove this evidence from a cylinder. We are adopting ultrasonic 
examination requirements when grinding is conducted, as proposed. It is 
PHMSA's understanding that cylinder repair facilities already regularly 
conduct ultrasonic examination whenever wall thickness is removed or in 
question, therefore this requirement should not impose any additional 
burden on cylinder repairers. Finally, we are adopting as proposed a 
new marking requirement for repaired cylinders to indicate compliance 
with the repair requirements.

Section 180.213

    Section 180.213 prescribes requirements for marking DOT-
specification cylinders and UN pressure receptacles that are 
successfully requalified. In this final rule, we also clarify the 
marking requirements for foreign cylinders filled for export under 
paragraph (d). The final rule includes two new marking requirements 
under paragraph (f):
    <bullet> Designation of grinding with ultrasonic wall thickness 
examination; and
    <bullet> designation of requalification of a foreign cylinder for 
export only requalified in conformance with Sec. Sec.  171.23(a)(5) and 
180.209(l) of the HMR. The ``EX'' marking for foreign cylinders 
requalified for export only should not be confused with explosive 
approvals numbers.
    Finally, we add visual inspection identifier number marking 
requirements under a new paragraph (g) that codify the requirements 
already found in visual requalifier approval documents.

Section 180.215

    Section 180.215 prescribes reporting and retention requirements for 
a person who requalifies, repairs, or rebuilds cylinders. In this final 
rule, we revise what information these documents must contain: For 
calibration certificates, requalifiers must now retain a copy of the 
most recent calibration certificate for their pressure indicating 
device and expansion indicating device, to align with CGA C-1 
requirements incorporated by reference under this final rule; 
correcting an ambiguity in Sec.  180.215(c)(2)(vii) to clarify that 
records for both proof pressure and volumetric expansion tests after 
re-building a 4-series cylinder must be preserved; and for DOT 3-series 
cylinders repaired using grinding, a record of the performance of 
grinding repairs and ultrasonic examination.

VIII. Regulatory Analyses and Notices

A. Statutory/Legal Authority for This Final Rule

    This rulemaking responds to 20 petitions for rulemaking, one 
special permit, and several agency-identified issues that have a 
potential effect on hazardous materials transportation safety. Federal 
Hazardous Materials Transportation Law (49 U.S.C. 5101-5128) authorizes 
the Secretary of Transportation to ``prescribe regulations for the safe 
transportation, including security, of hazardous material in 
intrastate, interstate, and foreign commerce.'' The Secretary's 
authority is delegated to PHMSA at 49 CFR 1.97.

B. Executive Order 12866 and DOT Policies and Procedures for 
Rulemakings

    This final rule is not considered a significant regulatory action 
under section 3(f) of Executive Order (E.O.) 12866, ``Regulatory 
Planning and Review,'' 58 FR 51735, and was not reviewed by the Office 
of Management and Budget (OMB). This rule is also not significant under 
the Department of Transportation's Policies and Procedures for 
Rulemakings (DOT Order 2100.6; Dec. 20, 2018).
    E.O. 12866 requires agencies to design regulations ``in the most 
cost-effective manner,'' to make a ``reasoned determination that the 
benefits of the intended regulation justify its costs,'' and to develop 
regulations that ``impose the least burden on society.'' In this final 
rule, PHMSA accomplishes the directives of E.O. 12866 by involving the 
public and exercising its own independent judgment in responding to 20 
petitions for rulemaking submitted by stakeholders in the compressed 
gas industry. The final rule clarifies the regulatory text in the HMR 
and incorporates widely used consensus standards to addresses specific 
safety concerns, thus enhancing the safe transportation of compressed 
gases while limiting the impact on the regulated community. 
Additionally, some of the provisions will provide shippers and carriers 
with additional flexibility to comply with established safety 
requirements, thereby reducing burdens and costs and increasing 
productivity.
    Overall, the issues discussed in this final rule promote the 
continued safe transportation of hazardous materials while producing 
net cost savings. PHMSA estimates the net cost savings associated with 
this rule is approximately $70,000 per year, at a 7 percent discount 
rate, over a ten-year analysis period from 2019 to 2028. Details on the 
estimated cost savings of this final rule can be found in the rule's 
economic analysis, which is available in the public docket.

C. Executive Order 13771

    This final rule is considered a deregulatory action under E.O. 
13771. Details on the estimated cost savings of this final rule can be 
found in the rule's Regulatory Impact Analysis, available at 
www.regulations.gov.

D. Executive Order 13132

    This final rule was analyzed in accordance with the principles and 
criteria contained in Executive Order 13132, ``Federalism,'' 64 FR 
43255. E.O. 13132 requires agencies to assure meaningful and timely 
input by State and local officials in the development of regulatory 
policies that may have ``substantial direct effects on the States, on 
the relationship between the national government and the States, or on 
the distribution of power and responsibilities among the various levels 
of government.'' This final rule may preempt State, local, and Native 
American tribal requirements but does not propose any regulation that 
has substantial direct effects on the States, the relationship between 
the National Government and the States, or the distribution of power 
and responsibilities among the various levels of government. Therefore, 
the consultation and funding requirements of Executive Order 13132 do 
not apply.
    The Federal Hazardous Materials Transportation Law contains an 
express preemption provision, 49 U.S.C. 5125(b), that preempts State, 
local, and Native American tribal requirements on the following 
subjects unless the non-Federal requirements are ``substantively the 
same'' as the Federal requirements:
    (1) The designation, description, and classification of hazardous 
materials;
    (2) The packing, repacking, handling, labeling, marking, and 
placarding of hazardous materials;
    (3) The preparation, execution, and use of shipping documents 
related to hazardous materials and requirements related to the number, 
contents, and placement of those documents;

[[Page 85412]]

    (4) The written notification, recording, and reporting of the 
unintentional release in transportation of hazardous material; and
    (5) The design, manufacture, fabrication, marking, maintenance, 
recondition, repair, or testing of a packaging or container 
represented, marked, certified, or sold as qualified for use in 
transporting hazardous material.
    This final rule addresses subjects (1), (2), and (5) above. 
Therefore, this final rule will preempt any State, local, or tribal 
requirements concerning these subjects unless the non-Federal 
requirements are ``substantively the same'' as the Federal 
requirements. PHMSA received no comments on the NPRM regarding the 
effect of the adoption of the specific proposals would have on State or 
local governments.

E. Executive Order 13175

    This final rule was analyzed in accordance with the principles and 
criteria contained in Executive Order 13175, ``Consultation and 
Coordination with Indian Tribal Governments,'' 79 FR 4748. E.O. 13175 
requires agencies to assure meaningful and timely input from Indian 
tribal government representatives in the development of rules that 
significantly or uniquely affect Tribal communities by imposing 
``substantial direct compliance costs'' or ``substantial direct 
effects'' on such communities or the relationship and distribution of 
power between the Federal Government and Indian tribes. This final rule 
is generally directed at offerors and shippers of DOT-specification 
cylinders and UN pressure receptacles that transport hazardous 
materials in U.S. commerce. The final rule is also likely to affect 
cylinder manufacturers; cylinder requalifiers; independent inspection 
agencies; commercial establishments that own and use DOT-specification 
cylinders and UN pressure receptacles. It does not impose substantial 
direct compliance costs and does not have substantial direct effects on 
Native American tribal governments. Therefore, the funding and 
consultation requirements of E.O. 13175 do not apply, and a tribal 
summary impact statement is not required. Further, PHMSA did not 
receive comments on the tribal implications of the rulemaking.

F. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Procedures and Policies

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires an 
agency to review regulations to assess their impact on small entities 
unless the agency determines that a rule is not expected to have a 
significant impact on a substantial number of small entities. Executive 
Order 13272, ``Proper Consideration of Small Entities in Agency 
Rulemaking,'' 68 FR 7990, requires agencies to establish procedures and 
policies to promote compliance with the Regulatory Flexibility Act and 
to ``thoroughly review draft rules to assess and take appropriate 
account of the potential impact'' of the rules on small businesses, 
governmental jurisdictions and small organizations. This rule was 
developed in accordance with this E.O. and DOT's procedures and 
policies to promote compliance with the Regulatory Flexibility Act to 
ensure that potential impacts on small entities of a regulatory action 
were properly considered.
    Section 603(b) of the Regulatory Flexibility Act requires an 
analysis of the possible impact of the rule on small entities, 
including the need for the rule, the description of the action, the 
identification of potentially affected small entities, the reporting 
and recordkeeping requirements, the related Federal rules and 
regulations, and the alternative proposals considered. Such analysis 
for this final rule is as follows:
1. Need for the Final Rule
    Current requirements for the manufacture, use, and requalification 
of cylinders can be traced to standards first applied in the early 
1900s. Over the years, the regulations have been revised to reflect 
advancements in transportation efficiency and changes in the national 
and international economic environment. This final rule is part of an 
agency effort to conduct a retrospective review of existing 
regulations. The final rule attempts to modify and streamline existing 
requirements that are outmoded, ineffective, insufficient, or 
excessively burdensome. As part of this effort, this rulemaking 
introduces new provisions suggested or developed by industry 
representatives, groups that develop consensus standards, and 
international regulatory bodies.
2. Description of Action
    This final rule responds to 20 petitions for rulemaking, clarifies 
other requirements in the HMR, and addresses areas of concern that are 
currently left out of the HMR. The amendments discussed in this final 
rule are designed to increase flexibility for the regulated community, 
promote technological advancement, and facilitate international 
transportation while maintaining a comparable level of safety.
3. Identification of Potentially Affected Small Entities
    The term ``small entities,'' as described in 5 U.S.C. 601, 
comprises small businesses and not-for-profit organizations that are 
independently owned and operated and are not dominant in their fields 
and governmental jurisdictions with populations of less than 50,000. 
The amendments considered here are likely to affect cylinder 
manufacturers (NAICS code 332420; approximately 568 companies); 
cylinder requalifiers; independent inspection agencies; commercial 
establishments that own and use DOT-specification cylinders and UN 
pressure receptacles; and individuals who export non-UN/ISO compressed 
gas cylinders (NAICS codes 32512, 336992, 423450, 423850, 423990, 
454312, and 541380). Nearly all of these companies, particularly 
cylinder requalification facilities (approximately 5,000 in total) are 
small entities based on the criteria developed by the Small Business 
Administration.
4. Reporting and Recordkeeping Requirements
    This final rule includes very minor reporting and recordkeeping 
requirements.
5. Related Federal Rules and Regulations
    The Occupational Safety and Health Administration (OSHA) prescribes 
requirements for the use, maintenance, and testing of portable fire 
extinguishers in 29 CFR 1910.157 and requirements for fixed fire 
suppression systems in 29 CFR 1910.160. The issues discussed in this 
final rule pertaining to the transportation of fire extinguishers and 
compressed gas cylinders that are a component of a fixed fire 
suppression system do not conflict with the requirements in OSHA 
regulations. With respect to the transportation of compressed gases in 
cylinders, there are not related rules or regulations issued by other 
departments or agencies of the Federal government.
6. Alternative Proposals for Small Business
    The Regulatory Flexibility Act directs agencies to establish 
exceptions and differing compliance standards for small businesses, 
where it is possible to do so and still meet the objectives of 
applicable regulatory statutes. The proposed changes are generally 
intended to provide cost savings to industry members. PHMSA received no

[[Page 85413]]

comments from small entities on specific small business impacts from 
these additional requirements.
7. Conclusion
    This final rule reduces burdens for most persons and any costs 
resulting from adoption of new requirements will be minimal and will be 
offset by cost savings. Additionally, the rule will create additional 
unquantified ancillary benefits and cost savings derived from 
increasing regulatory flexibility and improving safety through enhanced 
clarity.

G. Paperwork Reduction Act

    PHMSA has analyzed this rule in accordance with the Paperwork 
Reduction Act of 1995 (PRA) (Pub. L. 96-511). PHMSA stated in the NPRM 
that the proposals did not impose new information collection 
requirements. However, PHMSA did receive a comment from Hydro-Test 
Products related to proposed changes to Sec.  180.215 on the addition 
of the date of manufacture to test record forms. The commenter noted 
that PHMSA did not address the paperwork burden for the proposed 
requirement in Sec.  180.215. To address this comment PHMSA is 
accounting for a minor adjustment to information on a requalification 
test report under OMB control number 2137-0022 titled ``Testing, 
Inspection, and Marking Requirements for Cylinders.'' PHMSA estimates 
based on our experience observing the activities of cylinder 
requalifiers during compliance inspections that it will take one 
additional second to write the date of manufacture on the cylinder 
requalification record. PHMSA currently estimates there are 6,790,000 
cylinder requalifications conducted each year. The additional one 
second of burden to these reports will result in additional time burden 
of 1,886 hours (6,790,000 annual reports x 1 second).
    Furthermore, upon review of this rule, PHMSA is accounting for 
additional burden in this rulemaking. In the NPRM, PHMSA also proposed 
a requirement in Sec.  178.35 to mark the tare weight, mass weight, and 
water capacity on DOT 4B, 4BA, 4BW, or 4E cylinders. The language in 
the final rule will codify language in Sec.  178.35 to require that 
DOT-specification 4B, 4BA, 4BW, and 4E cylinders used in liquefied 
compressed gas service manufactured two years after publication of this 
rule to be marked with the tare weight, mass weight, and water 
capacity. PHMSA already accounts for the marking of new cylinders under 
Sec.  178.35 under the previously mentioned OMB Control Number 2137-
0022. PHMSA estimates based on our knowledge of modern automated 
cylinder manufacturing processes from direct observation during 
compliance inspections that this additional marking information will 
take an additional 3 minutes, for an increase in approximately 3,472 
hours on an annual basis.
    Additionally, PHMSA proposed a requirement in Sec.  180.215(b)(4) 
to require cylinder requalifiers to retain the most recent calibration 
certificate for their pressure indicating device (PID) and expansion 
indicating device (EID). PHMSA already accounts for creation of records 
related to cylinder requalification under Sec.  180.215 under OMB 
Control Number 2137-0022. After the incorporation of CGA C-1, each 
requalifier will be required to re-calibrate their PID every 6 months. 
There are approximately 2,300 cylinder requalifiers approved by PHMSA 
to conduct pressure tests on cylinders, therefore we estimate that 
4,600 PID calibration certificates will be generated each year. We 
estimate that it will take the gauge calibration facility 5 minutes to 
generate each certificate, based on our knowledge of the information 
contained on the certificate. This results in a new information 
collection burden of approximately 383 hours for gauge calibration 
facilities. Based on our experience inspecting cylinder requalification 
facilities, we believe that gauge calibration facilities already 
provide this record as part of their business practices and there will 
be no additional cost burden associated with this requirement.
    Expansion indicating devices (EIDs) are either burette systems or 
scale-based systems. Burette systems do not require recalibration 
because their accuracy is fixed at the time the glass burette tube is 
measured and printed with volume graduations. CGA C-1 requires that 
scale-based EID systems are recalibrated as provided in the 
manufacturer's manual. PHMSA has reviewed a manufacturer's manual for a 
scale-based system and determined that scale calibration is only 
required when the scale cannot display an accurate weight when tested 
with an object of known mass (e.g. a 100-gram test weight provided with 
the system). Based on our experience conducting inspections at cylinder 
requalification facilities, this is an uncommon occurrence. Based on 
our experience inspecting cylinder requalification facilities, we 
estimate that 10% of cylinder requalifiers need to recalibrate their 
scale-based EID systems each year, resulting in the generation of 230 
re-calibration certificates annually. We estimate that it will take the 
scale calibration facility 5 minutes to generate each certificate, 
based on our knowledge of the information contained on the certificate, 
which results in an increase of approximate 19 hours in burden. Based 
on our experience inspecting cylinder requalification facilities, we 
believe that scale calibration facilities already provide this record 
as part of their business practices and there will be no additional 
cost burden associated with this requirement.
    Finally, PHMSA proposed a requirement in Sec. Sec.  178.50(b), 
178.51(b), 178.61(b), and 178.68(b) to require manufacturers of DOT 4B, 
4BA, 4BW, and 4E cylinders to keep a record of intentionally added 
alloying elements in the steel or aluminum used to produce the 
cylinders. PHMSA already accounts for recordkeeping related to the 
production of cylinders under OMB Control Number 2137-0022. PHMSA 
estimates based on our knowledge of cylinder manufacturer practices 
from direct observation during compliance inspections that this 
additional recordkeeping will take an additional 23 hours affecting 23 
manufacturers.
    This rulemaking identifies revised information collection requests 
that PHMSA will submit to OMB for approval based on the requirements in 
this final rule. PHMSA has developed burden estimates to reflect 
changes in this final rule and estimates the information collection and 
recordkeeping burdens in this rule are as follows:
    Annual Increase in Number of Respondents: 4,623.
    Annual Increase in Annual Number of Responses: 4,853.
    Annual Increase in Annual Burden Hours: 5,783.

H. Regulation Identifier Number (RIN)

    A regulation identifier number (RIN) is assigned to each regulatory 
action listed in the Unified Agenda of Federal Regulations. The 
Regulatory Information Service Center publishes the Unified Agenda in 
April and October of each year. The RIN contained in the heading of 
this document may be used to cross-reference this action with the 
Unified Agenda.

I. Unfunded Mandates Reform Act of 1995

    The Unfunded Mandates Reform Act (UMRA) of 1995, Public Law 104-4, 
establishes significance thresholds for the direct costs of regulations 
on State, local, or tribal governments or the private sector that 
trigger certain agency reporting requirements. The statutory thresholds 
established in UMRA were $50 million for intergovernmental mandates and 
$100 million for private-

[[Page 85414]]

sector mandates in 1996. According to the Congressional Budget Office, 
the thresholds for 2019, which are adjusted annually for inflation, are 
$82 million and $164 million, respectively, for intergovernmental and 
private-sector mandates.\12\ This final rule results in cost savings 
and is the least burdensome alternative that achieves the objective of 
the rule. It is not significant under UMRA. Therefore, PHMSA is not 
required to prepare a written statement.
---------------------------------------------------------------------------

    \12\ https://www.cbo.gov/publication/51335.
---------------------------------------------------------------------------

J. Environmental Assessment

    The National Environmental Policy Act of 1969 (NEPA), as amended 
(42 U.S.C. 4321-4347), and implementing regulations by the Council on 
Environmental Quality (CEQ) (40 CFR part 1500), require Federal 
agencies to consider the consequences of major Federal actions and 
prepare a detailed statement on actions that significantly affect the 
quality of the human environment. The CEQ regulations require Federal 
agencies to conduct an environmental review considering: (1) The need 
for the proposed action; (2) alternatives to the proposed action; (3) 
probable environmental impacts of the proposed action and alternatives; 
and (4) the agencies and persons consulted during the consideration 
process.
1. Need for the Action
    This final rule responds to 20 petitions for rulemaking submitted 
by the regulated community. The issues discussed in this final rule 
will update and expand the use of currently authorized industry 
consensus standards; revise the construction, marking, and testing 
requirements of DOT 4-series cylinders; clarify the filling 
requirements for cylinders; discuss the handling of cylinders used in 
fire suppression systems; and revise the requalification requirements 
for cylinders.
    This final rule discusses the following amendments to the HMR:
    <bullet> Replace the currently incorporated Seventh Edition of the 
CGA's publication C-6 Standards for Visual Inspection of Steel 
Compressed Gas Cylinders with the revised Eleventh Edition and update 
the appropriate references throughout the HMR.
    <bullet> Revise the manufacturing requirements for certain DOT 4-
series cylinders.
    <bullet> Revise the requirements for the requalification of DOT-
specification cylinders by pressure testing found in 49 CFR part 180, 
subpart C.
    <bullet> Allow the use of the labels described in the Eighth 
Edition of CGA's publication C-7 Guide to the Preparation of 
Precautionary Labeling and Marking of Compressed Gas Containers (Tenth 
edition currently incorporated by reference in the HMR) Appendix A on 
cylinders contained in overpacks.
    <bullet> Require manufacturers to mark certain newly manufactured 
cylinders suitable for the transport of liquefied compressed gas with 
the mass weight or tare weight, and water capacity.
    <bullet> Allow non-specification cylinders used in a fixed fire 
suppression system to be transported under the same exceptions as those 
provided for fire extinguishers, under certain conditions and 
limitations.
    <bullet> Clarify filling limits for a liquefied compressed gas in a 
manifold or a multiple element gas container (MEGC).
    <bullet> Clarify the requirements for filling non-specification 
cylinders for export or use on board a vessel.
2. Alternatives Considered
    Alternative (1) No Action: Under this alternative, the current 
regulatory standards would remain in effect. PHMSA would not adopt any 
of the petitions or incorporate any of the special permits under 
consideration. As a result, PHMSA would not update, clarify, and 
provide relief from certain existing regulatory requirements to promote 
safer transportation practices, eliminate unnecessary regulatory 
requirements, and facilitate international commerce. We rejected the no 
action alternative.
    Alternative (2) Preferred Alternative: With this alternative, PHMSA 
responds to 20 petitions for rulemaking, clarifies other requirements 
in the HMR, and addresses areas of concern that are currently left out 
of the HMR.
3. Environmental Impacts
    Hazardous materials are substances that may pose a threat to public 
safety or the environment during transportation because of their 
physical, chemical, or nuclear properties. Under the HMR, hazardous 
materials are transported by aircraft, vessel, rail, and highway. The 
hazardous materials regulatory system is a risk management system that 
is prevention-oriented and focused on identifying a safety hazard and 
reducing the probability and quantity of a hazardous material release. 
The potential for environmental damage or contamination exists when 
packages of hazardous materials are involved in accidents or en route 
incidents resulting from cargo shifts, valve failures, package 
failures, loading, unloading, collisions, handling problems, or 
deliberate sabotage. The release of hazardous materials can cause the 
loss of ecological resources (e.g., wildlife habitats) and the 
contamination of air, aquatic environments, and soil. Contamination of 
soil can lead to the contamination of ground water. Compliance with the 
HMR substantially reduces the possibility of accidental release of 
hazardous materials.
    Anticipated Impact under Alternative (1) No Action: Potential for 
increased releases of hazardous materials due to unclear regulatory 
language and use of outdated industry standards.
    Anticipated Impact under Alternative (2) Preferred Alternative: 
Decreased releases of hazardous materials due to increased clarity of 
regulatory requirements and updated industry standards. Specifically, 
increased clarity for MEGC filling requirements will decrease the 
chances of pressure receptacle overfill which can result in 
catastrophic releases of hazardous materials. It is anticipated that 
the petitions discussed in this final rule would have minimal, if any, 
environmental consequences.
4. Agencies Consulted
Occupational Safety and Health Administration
National Institute of Standards and Technology
U.S. Environmental Protection Agency
5. Conclusion
    PHMSA has conducted a technical review of the amendments discussed 
in this final rule and determined that no significant environmental 
impact will result from this final rule. The amendments would provide 
protection against the release of hazardous materials based on sound 
scientific methods and would not result in unusual stresses on the 
cylinders used to contain these hazardous materials or adversely impact 
human health or the environment. PHMSA received no comments 
specifically addressing the environmental impacts of changes made in 
this final rule.

K. Privacy Act

    In accordance with 5 U.S.C. 553(c), DOT solicits comments from the 
public to better inform its rulemaking process. DOT posts these 
comments, without edit, including any personal information the 
commenter provides, to www.regulations.gov, as described in the system 
of records notice (DOT/ALL-14 FDMS), which can be reviewed at 
www.dot.gov/privacy.

[[Page 85415]]

L. International Trade Analysis and Executive Order 13609

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the 
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal 
agencies from establishing any standards or engaging in related 
activities that create unnecessary obstacles to the foreign commerce of 
the United States. Pursuant to these Acts, the establishment of 
standards is not considered an unnecessary obstacle to the foreign 
commerce of the United States, so long as the standards have a 
legitimate domestic objective, such as the protection of safety, and do 
not operate in a manner that excludes imports that meet this objective. 
The statute also requires consideration of international standards, and 
where appropriate, that they be the basis for U.S. standards. PHMSA 
notes the purpose is to ensure the safety of the American public and 
has assessed the effects of this final rule to ensure that it does not 
exclude imports that meet this objective. The final rule may have 
positive impacts on international trade because it increases the level 
of harmonization between U.S. regulations and international standards, 
which is also consistent with the policy in Executive Order 13609, 
``Promoting International Regulatory Cooperation,'' 77 FR 26413. As a 
result, this final rule is not considered as creating an unnecessary 
obstacle to foreign commerce.

M. National Technology Transfer and Advancement Act

    The National Technology Transfer and Advancement Act of 1995 (15 
U.S.C. 272 note) directs Federal agencies to use voluntary consensus 
standards in their regulatory activities unless doing so would be 
inconsistent with applicable law or otherwise impractical. Voluntary 
consensus standards are technical standards (e.g., specification of 
materials, test methods, or performance requirements) that are 
developed or adopted by voluntary consensus standards bodies. This 
final rule adopts five voluntary consensus standards developed by the 
Compressed Gas Association, which are discussed in detail in the 
``Section-by-Section Review'' for Sec.  171.7.

List of Subjects

49 CFR Part 107

    Administrative practice and procedure, Hazardous materials 
transportation, Penalties, Reporting and recordkeeping requirements.

49 CFR Part 171

    Exports, Hazardous materials transportation, Hazardous waste, 
Imports, Incorporation by reference, Reporting and recordkeeping 
requirements.

49 CFR Part 173

    Hazardous materials transportation, Incorporation by reference, 
Packaging and containers, Radioactive materials, Reporting and 
recordkeeping requirements, Uranium.

49 CFR Part 178

    Hazardous materials transportation, Incorporation by reference, 
Motor vehicle safety, Packaging and containers, Reporting and 
recordkeeping requirements.

49 CFR Part 180

    Hazardous materials transportation; Motor carriers, Incorporation 
by reference, Motor vehicle safety, Packaging and containers, Railroad 
safety, Reporting and recordkeeping requirements.

    In consideration of the foregoing, PHMSA amends 49 CFR chapter I as 
follows:

PART 107--HAZARDOUS MATERIALS PROGRAM PROCEDURES

0
1. The authority citation for part 107 continues to read as follows:

    Authority:  49 U.S.C. 5101-5128, 44701; Pub. L. 101-410, Section 
4; Pub. L. 104-121, Sections 212-213; Pub. L. 104-134, Section 
31001; Pub. L. 114-74, Section 4 (28 U.S.C. 2461 note); 49 CFR 1.81 
and 1.97; 33 U.S.C. 1321.


0
2. In Sec.  107.803, revise paragraph (c)(3) to read as follows:


Sec.  107.803   Approval of an independent inspection agency (IIA).

* * * * *
    (c) * * *
    (3) Detailed description of the applicant's qualifications and 
ability to perform the inspections and to verify the inspections 
required by parts 178 and 180 of this chapter; or those required under 
the terms of a special permit issued under this part.
* * * * *

0
3. In Sec.  107.805, revise paragraphs (c)(3) and (4) and add paragraph 
(c)(5) to read as follows:


Sec.  107.805   Approval of cylinder and pressure receptacle 
requalifiers.

* * * * *
    (c) * * *
    (3) A certification that the facility will operate in compliance 
with the applicable requirements of subchapter C of this chapter;
    (4) The signature of the person making the certification and the 
date on which it was signed; and
    (5) For a mobile unit operation (as defined in Sec.  180.203 of 
subchapter C of this chapter), the type of equipment to be used, the 
specific vehicles to be used, the geographic area the applicant is 
requesting to operate within, and any differences between the mobile 
operation and the facility operation as described under paragraph 
(c)(2) of this section.
* * * * *

PART 171--GENERAL INFORMATION, REGULATIONS, AND DEFINITIONS

0
4. The authority citation for part 171 continues to read as follows:

    Authority: 49 U.S.C. 5101-5128, 44701; Pub. L. 101-410, Section 
4; Pub. L. 104-134, Section 31001; Pub. L. 114-74, Section 4 (28 
U.S.C. 2461 note); 49 CFR 1.81 and 1.97.


0
5. In Sec.  171.7:
0
a. Revise paragraph (a)(2)(ii);
0
b. Remove paragraph (n)(16) and redesignate paragraphs (n)(1) through 
(15) as paragraphs (n)(2) through (16);
0
c. Add new paragraph (n)(1) and revise newly redesignated paragraphs 
(n)(2), (4), and (13) and paragraph (n)(18).
    The revisions and addition read as follows:


Sec.  171.7   Reference material.

    (a) * * *
    (2) * * *
    (ii) The National Archives and Records Administration (NARA). For 
information on the availability of this material at NARA, email 
<a href="/cdn-cgi/l/email-protection#c1a7a4a5b3a4a6efada4a6a0ad81afa0b3a0efa6aeb7"><span class="__cf_email__" data-cfemail="f89e9d9c8a9d9fd6949d9f9994b896998a99d69f978e">[email protected]</span></a>, or go to www.archives.gov/federal-register/cfr/ibr-locations.html.
* * * * *
    (n) * * *
    (1) CGA C-1--2016, Methods for Pressure Testing Compressed Gas 
Cylinders, Eleventh edition, copyright 2016, into Sec. Sec.  178.36, 
178.37, 178.38, 178.39, 178.42, 178.44, 178.45, 178.46, 178.47; 178.50; 
178.51; 178.53; 178.55; 178.56; 178.57; 178.58; 178.59; 178.60; 178.61; 
178.65; 178.68; 180.205, 180.209.
    (2) CGA C-3--2005 (Reaffirmed 2011), Standards for Welding on Thin-
Walled Steel Cylinders, Seventh edition, copyright 2005, into 
Sec. Sec.  178.47; 178.50; 178.51; 178.53; 178.55; 178.56; 178.57; 
178.58; 178.59; 178.60; 178.61; 178.65; 178.68; 180.211.
* * * * *
    (4) CGA C-6--2013, Standards for Visual Inspection of Steel 
Compressed

[[Page 85416]]

Gas Cylinders, Eleventh edition, copyright 2013, into Sec. Sec.  
172.102, 173.3, 173.198, 180.205, 180.209, 180.211, 180.411, 180.519.
* * * * *
    (13) CGA C-14--2005 (Reaffirmed 2010), Procedures for Fire Testing 
of DOT Cylinder Pressure Relief Device Systems, Fourth edition, 
copyright 2005, into Sec. Sec.  173.301; 173.323.
* * * * *
    (18) CGA S-1.1--2011, Pressure Relief Device Standards--Part 1--
Cylinders for Compressed Gases, Fourteenth edition, copyright 2011, 
into Sec. Sec.  173.301; 173.304a; 178.75.
* * * * *

0
6. In Sec.  171.23, revise paragraph (a)(5)(i) to read as follows:


Sec.  171.23   Requirements for specific materials and packagings 
transported under the ICAO Technical Instructions, IMDG Code, Transport 
Canada TDG Regulations, or the IAEA Regulations.

* * * * *
    (a) * * *
    (5) * * *
    (i) The cylinder has been requalified and marked in accordance with 
subpart C of part 180 of this subchapter, or has been requalified as 
authorized by the Associate Administrator;
* * * * *

PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENTS AND 
PACKAGINGS

0
7. The authority citation for part 173 continues to read as follows:

    Authority:  49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and 
1.97.


0
8. In Sec.  173.3, revise paragraph (d)(1) to read as follows:


Sec.  173.3   Packaging and exceptions.

* * * * *
    (d) * * *
    (1) Except for Class 1, Division 6.2, Class 7, or acetylene 
material, a cylinder containing a hazardous material may be overpacked 
in a salvage cylinder.
* * * * *

0
9. In Sec.  173.301:
0
a. In paragraphs (c) and (f), remove ``9.1.1.1'' and add in its place 
``9.1.1'' in each place it appears; and
0
b. Revise paragraph (f)(4).
    The revision reads as follows:


Sec.  173.301   General requirements for shipment of compressed gases 
and other hazardous materials in cylinders, UN pressure receptacles and 
spherical pressure vessels.

* * * * *
    (f) * * *
    (4)(i) A pressure relief device is required on a DOT 39 cylinder 
regardless of cylinder size or filled pressure.
    (ii) A DOT 39 cylinder used for liquefied Division 2.1 materials 
must be equipped with a metal pressure relief device.
    (iii) Fusible pressure relief devices are not authorized on a DOT 
39 cylinder containing a liquefied gas.
    (iv) A pressure relief device for oxidizing gases transported by 
air in a DOT 39 cylinder must meet the requirements of Sec.  
173.302(f)(2)(iii) of this subpart for permanent gases and Sec.  
173.304(f)(2)(iii) for liquefied compressed gases.
* * * * *

0
10. In Sec.  173.302, revise paragraphs (f)(2)(i) and (ii) and add 
paragraph (f)(2)(iii) to read as follows:


Sec.  173.302   Filling of cylinders with nonliquefied (permanent) 
compressed gases or adsorbed gases.

* * * * *
    (f) * * *
    (2) * * *
    (i) The rated burst pressure of a rupture disc for DOT 3A, 3AA, 
3AL, and 3E cylinders, and UN pressure receptacles ISO 9809-1, ISO 
9809-2, ISO 9809-3 and ISO 7866 cylinders must be 100% of the cylinder 
minimum test pressure with a tolerance of plus zero to minus 10%;
    (ii) The rated burst pressure of a rupture disc for a DOT 3HT 
cylinder must be 90% of the cylinder minimum test pressure with a 
tolerance of plus zero to minus 10%; and
    (iii) The rated burst pressure of a rupture disc for a DOT 39 
cylinder must be not more than 80 percent of cylinder burst pressure 
but not less than 105 percent of cylinder test pressure. Cylinders 
filled and offered for transportation in accordance with the 
requirements of the section before January 27, 2021 may continue to be 
used for the life of the packaging.
* * * * *

0
11. In Sec.  173.302a, revise paragraphs (a)(3) and (c)(4)(i) and (ii) 
and add paragraph (c)(4)(iii) to read as follows:


Sec.  173.302a   Additional requirements for shipment of nonliquefied 
(permanent) compressed gases in specification cylinders.

    (a) * * *
    (3) DOT 39 cylinders. When the cylinder is filled with a Division 
2.1 flammable gas, the internal volume of the cylinder may not exceed 
1.23 L (75 in\3\). For chemical under pressure (see Sec.  172.102 of 
this subchapter (special provision 362)), the internal volume may not 
exceed the size limits of the specification as provided in Sec.  
178.65(a)(1) of this subchapter.
* * * * *
    (c) * * *
    (4) * * *
    (i) Cylinders less than 1.7 m (65 inches) in length must be 
equipped with fusible metal backed frangible disc devices;
    (ii) Cylinders 1.7 m (65 inches) or greater in length and 24.5 cm 
(9.63 inches) in diameter or larger must be equipped with fusible metal 
backed frangible disc devices or frangible disc devices, except as 
provided in paragraph (c)(4)(iii) of this section. Cylinders with a 
diameter of 0.56 m (22 inches) or larger must be equipped with 
frangible disc devices except as provided in paragraph (c)(4)(iii) of 
this section.
    (iii) Cylinders greater than 3.66 m (144 inches) in length that are 
horizontally mounted on a motor vehicle, in an ISO framework, or other 
framework of equivalent structural integrity are not required to be 
equipped with pressure relief devices. If such devices are installed, 
they must be selected in accordance with Sec.  173.301(f).
* * * * *

0
12. In Sec.  173.304, revise paragraphs (f)(2)(i) and (ii) and add 
paragraph (f)(2)(iii) to read as follows:


Sec.  173.304   Filling of cylinders with liquefied compressed gases.

* * * * *
    (f) * * *
    (2) * * *
    (i) The rated burst pressure of a rupture disc for DOT 3A, 3AA, 
3AL, and 3E cylinders, and UN pressure receptacles ISO 9809-1, ISO 
9809-2, ISO 9809-3, and ISO 7866 cylinders must be 100% of the cylinder 
minimum test pressure with a tolerance of plus zero to minus 10%;
    (ii) The rated burst pressure of a rupture disc for a DOT 3HT 
cylinder must be 90% of the cylinder minimum test pressure with a 
tolerance of plus zero to minus 10%; and
    (iii) The rated burst pressure of a rupture disc for a DOT 39 
cylinder must be not more than 80 percent of cylinder burst pressure 
but not less than 105 percent of cylinder test pressure. Cylinders 
filled and offered for transportation in accordance with the 
requirements of the section before January 27, 2021 may continue to be 
used for the life of the packaging.

0
13. In Sec.  173.304a:
0
a. Revise paragraph (a)(2); and
0
b. Add paragraph (a)(3); and
0
c. Revise paragraph (d)(3)(i).

[[Page 85417]]

    The revisions and addition read as follows:


Sec.  173.304a   Additional requirements for shipment of liquefied 
compressed gases in specification cylinders.

    (a) * * *
    (2) For the gases named, the requirements in table 1 to paragraph 
(a)(2) apply (for cryogenic liquids, see Sec.  173.316):

                                           Table 1 to Paragraph (a)(2)
----------------------------------------------------------------------------------------------------------------
                                                                                    Packaging marked as shown in
                                                                                     this column or of the same
                                                                                      type with higher service
                                            Maximum permitted filling  density     pressure must be used, except
              Kind of gas                         (percent) (see Note 1)             as provided in Sec.  Sec.
                                                                                   173.301(l), 173.301a(e),  and
                                                                                       180.205(a) (see notes
                                                                                          following table)
----------------------------------------------------------------------------------------------------------------
Anhydrous ammonia.....................  54.......................................  DOT-3A480; DOT-3AA480; DOT-
                                                                                    3A480X; DOT-4AA480; DOT-3;
                                                                                    DOT-3E1800; DOT-3AL480.
Bromotrifluoromethane (R-13B1 or H-     124......................................  DOT-3A400; DOT-3AA400; DOT-
 1301).                                                                             3B400; DOT-4AA480; DOT-
                                                                                    4B400; DOT-4BA400; DOT-
                                                                                    4BW400; DOT-3E1800; DOT-39;
                                                                                    DOT-3AL400.
Carbon dioxide (see Notes 4, 7, and 8)  68.......................................  DOT-3A1800; DOT-3AX1800; DOT-
                                                                                    3AA1800; DOT-3AAX1800; DOT-
                                                                                    3; DOT-3E1800; DOT-3T1800;
                                                                                    DOT-3HT2000; DOT-39; DOT-
                                                                                    3AL1800.
Carbon dioxide (see Notes 4, 7, and 8)  70.3.....................................  DOT-3A2000, DOT-3AA2000, DOT-
                                                                                    3AX2000, DOT-3AAX2000, DOT-
                                                                                    3T2000.
Carbon dioxide (see Notes 4, 7, and 8)  73.2.....................................  DOT-3A2265, DOT-3AA2265, DOT-
                                                                                    3AX2265, DOT-3AAX2265, DOT-
                                                                                    3T2265.
Carbon dioxide (see Notes 4, 7, and 8)  74.5.....................................  DOT-3A2400, DOT-3AA2400, DOT-
                                                                                    3AX2400, DOT-3AAX2400, DOT-
                                                                                    3T2400.
Carbon dioxide, refrigerated liquid     .........................................  DOT-4L.
 (see paragraph (e) of this section).
Chlorine (see Note 2).................  125......................................  DOT-3A480; DOT-3AA480; DOT-3;
                                                                                    DOT-3BN480; DOT-3E1800.
Chlorodifluroethane or 1-Chloro-1, 1-   100......................................  DOT-3A150; DOT-3AA150; DOT-
 difluoroethane (R-142b).                                                           3B150; DOT-4B150; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-
                                                                                    3E1800; DOT-39; DOT-3AL150.
Chlorodifluoromethane (R-22) (see Note  105......................................  DOT-3A240; DOT-3AA240; DOT-
 8).                                                                                3B240; DOT-4B240; DOT-
                                                                                    4BA240; DOT-4BW240; DOT-
                                                                                    4B240ET; DOT-4E240; DOT-39;
                                                                                    DOT-3E1800; DOT-3AL240.
Chloropentafluorethane (R-115)........  110......................................  DOT-3A225; DOT-3AA225; DOT-
                                                                                    3B225; DOT-4BA225; DOT-
                                                                                    4B225; DOT-4BW225; DOT-
                                                                                    3E1800; DOT-39; DOT-3AL225.
Chlorotrifluoromethane (R-13) (see      100......................................  DOT-3A1800; DOT-3AA1800; DOT-
 Note 8).                                                                           3; DOT-3E1800; DOT-39; DOT-
                                                                                    3AL1800.
Cyclopropane (see Notes 8 and 9)......  55.......................................  DOT-3A225; DOT-3A480X; DOT-
                                                                                    3AA225; DOT-3B225; DOT-
                                                                                    4AA480; DOT4B225; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-
                                                                                    4B240ET; DOT-3; DOT-3E1800;
                                                                                    DOT-39; DOT-3AL225.
Dichlorodifluoromethane (R-12) (see     119......................................  DOT-3A225; DOT-3AA225; DOT-
 Note 8).                                                                           3B225; DOT-4B225; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-
                                                                                    4B240ET; DOT-4E225; DOT-39;
                                                                                    DOT-3E1800; DOT-3AL225.
Dichlorodifluoromethane and             Not liquid full at 131 [deg]F............  DOT-3A240; DOT-3AA240; DOT-
 difluoroethane mixture (constant                                                   3B240; DOT-3E1800; DOT-
 boiling mixture) (R-500) (see Note 8).                                             4B240; DOT-4BA240; DOT-
                                                                                    4BW240; DOT-4E240; DOT-39.
1,1-Difluoroethane (R-152a) (see Note   79.......................................  DOT-3A150; DOT-3AA150; DOT-
 8).                                                                                3B150; DOT-4B150; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-
                                                                                    3E1800; DOT-3AL150.
1,1-Difluoroethylene (R-1132A)........  73.......................................  DOT-3A2200; DOT-3AA2200; DOT-
                                                                                    3AX2200; DOT-3AAX2200; DOT-
                                                                                    3T2200; DOT-39.
Dimethylamine, anhydrous..............  59.......................................  DOT-3A150; DOT-3AA150; DOT-
                                                                                    3B150; DOT-4B150; DOT-
                                                                                    4BA225; DOT-4BW225; ICC-
                                                                                    3E1800.
Ethane (see Notes 8 and 9)............  35.8.....................................  DOT-3A1800; DOT-3AX1800; DOT-
                                                                                    3AA1800; DOT-3AAX1800; DOT-
                                                                                    3; DOT-3E1800; DOT-3T1800;
                                                                                    DOT-39; DOT-3AL1800.
Ethane (see Notes 8 and 9)............  36.8.....................................  DOT-3A2000; DOT-3AX2000; DOT-
                                                                                    3AA2000; DOT-3AAX2000; DOT-
                                                                                    3T2000; DOT-39; DOT-3AL2000.
Ethylene (see Notes 8 and 9)..........  31.0.....................................  DOT-3A1800; DOT-3AX1800; DOT-
                                                                                    3AA1800; DOT-3AAX1800; DOT-
                                                                                    3; DOT-3E1800; DOT-3T1800;
                                                                                    DOT-39; DOT-3AL1800.
Ethylene (see Notes 8 and 9)..........  32.5.....................................  DOT-3A2000; DOT-3AX2000; DOT-
                                                                                    3AA2000; DOT-3AAX2000; DOT-
                                                                                    3T2000; DOT-39; DOT-3AL2000.
Ethylene (see Notes 8 and 9)..........  35.5.....................................  DOT-3A2400; DOT-3AX2400; DOT-
                                                                                    3AA2400; DOT-3AAX2400; DOT-
                                                                                    3T2400; DOT-39; DOT-3AL2400.
Hydrogen chloride, anhydrous..........  65.......................................  DOT-3A1800; DOT-3AA1800; DOT-
                                                                                    3AX1800; DOT-3AAX1800; DOT-
                                                                                    3; DOT-3T1800; DOT-3E1800.
Hydrogen sulfide (Note 10)............  62.5.....................................  DOT-3A; DOT-3AA; DOT-3B; DOT-
                                                                                    4B; DOT-4BA; DOT-4BW; DOT-
                                                                                    3E1800; DOT-3AL.

[[Page 85418]]

 
Insecticide, gases liquefied (see       Not liquid full at 131 [deg]F............  DOT-3A300; DOT-3AA300; DOT-
 Notes 8 and 12).                                                                   3B300; DOT-4B300; DOT-
                                                                                    4BA300; DOT-4BW300; DOT-
                                                                                    3E1800.
Liquefied nonflammable gases, other     Not liquid full at 131 [deg]F............  Specification packaging
 than classified flammable, corrosive,                                              authorized in paragraph
 toxic & mixtures or solution thereof                                               (a)(1) of this section and
 filled w/nitrogen, carbon dioxide, or                                              DOT-3HT; DOT-4D; DOT-4DA;
 air (see Notes 7 and 8)..                                                          DOT-4DS.
Methyl acetylene-propadiene, mixtures,  Not liquid at 131 [deg]F.................  DOT-4B240 without brazed
 stabilized; (see Note 5)..                                                         seams; DOT-4BA240 without
                                                                                    brazed seams; DOT-3A240; DOT-
                                                                                    3AA240; DOT-3B240; DOT-
                                                                                    3E1800; DOT-4BW240; DOT-
                                                                                    4E240; DOT-4B240ET; DOT-
                                                                                    3AL240.
Methyl chloride.......................  84.......................................  DOT-3A225; DOT-3AA225; DOT-
                                                                                    3B225; DOT-4B225; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-3;
                                                                                    DOT-3E1800; DOT-4B240ET.
                                                                                    Cylinders complying with DOT-
                                                                                    3A150; DOT-3B150; and DOT-
                                                                                    4B150 manufactured prior to
                                                                                    Dec. 7, 1936 are also
                                                                                    authorized.
Methyl mercaptan......................  80.......................................  DOT-3A240; DOT-3AA240; DOT-
                                                                                    3B240; OT-4B240; DOT-
                                                                                    4B240ET; DOT-3E1800; DOT-
                                                                                    4BA240; DOT-4BW240.
Nitrosyl chloride.....................  110......................................  DOT-3BN400 only.
Nitrous oxide (see Notes 7, 8, and 11)  68.......................................  DOT-3A1800; DOT-3AX1800; DOT-
                                                                                    3AA1800; DOT-3AAX1800; DOT-
                                                                                    3; DOT-3E1800; DOT-3T1800;
                                                                                    DOT-3HT2000; DOT-39; DOT-
                                                                                    3AL1800.
Nitrous oxide (see Notes 7, 8, and 11)  70.3.....................................  DOT-3A2000, DOT-3AA2000, DOT-
                                                                                    3AX2000, DOT-3AAX2000, DOT-
                                                                                    3T2000.
Nitrous oxide (see Notes 7, 8, and 11)  73.2.....................................  DOT-3A2265, DOT-3AA2265, DOT-
                                                                                    3AX2265, DOT-3AAX2265, DOT-
                                                                                    3T2265.
Nitrous oxide (see Notes 7, 8, and 11)  74.5.....................................  DOT-3A2400, DOT-3AA2400, DOT-
                                                                                    3AX2400, DOT-3AAX2400, DOT-
                                                                                    3T2400.
Nitrous oxide, refrigerated liquid      .........................................  DOT-4L.
 (see paragraph (e) of this section.).
Refrigerant gas, n.o.s. or Dispersant   Not liquid full at 130 [deg]F............  DOT-3A240; DOT-3AA240; DOT-
 gas, n.o.s. (see Notes 8 and 13).                                                  3B240; DOT-3E1800; DOT-
                                                                                    4B240; DOT-4BA240; DOT-
                                                                                    4BW240; DOT-4E240; DOT-39;
                                                                                    DOT-3AL240.
Sulfur dioxide (see note 8)...........  125......................................  DOT-3A225; DOT-3AA225; DOT-
                                                                                    3B225; DOT-4B225; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-
                                                                                    4B240ET; DOT-3; DOT-39; DOT-
                                                                                    3E1800; DOT-3AL225.
Sulfur hexafluoride...................  120......................................  DOT-3A1000; DOT-3AA1000; DOT-
                                                                                    AAX2400; DOT-3; DOT-3AL1000;
                                                                                    DOT-3E1800; DOT-3T1800.
Sulfuryl fluoride.....................  106......................................  DOT-3A480; DOT-3AA480; DOT-
                                                                                    3E1800; DOT-4B480; DOT-
                                                                                    4BA480; DOT-4BW480.
Tetrafluoroethylene, stabilized.......  90.......................................  DOT-3A1200; DOT-3AA1200; DOT-
                                                                                    3E1800.
Trifluorochloroethylene, stabilized...  115......................................  DOT-3A300; DOT-3AA300; DOT-
                                                                                    3B300; DOT-4B300; DOT-
                                                                                    4BA300; DOT-4BW300; DOT-
                                                                                    3E1800.
Trimethylamine, anhydrous.............  57.......................................  DOT-3A150; DOT-3AA150; DOT-
                                                                                    3B150; DOT-4B150; DOT-
                                                                                    4BA225; DOT-4BW225; DOT-
                                                                                    3E1800.
Vinyl chloride (see Note 5)...........  84.......................................  DOT-4B150 without brazed
                                                                                    seams; DOT-4BA225 without
                                                                                    brazed seams; DOT-4BW225;
                                                                                    DOT-3A150; DOT-3AA150; DOT-
                                                                                    3E1800; DOT-3AL150.
Vinyl fluoride, stabilized............  62.......................................  DOT-3A1800; DOT-3AA1800; DOT-
                                                                                    3E1800; DOT-3AL1800.
Vinyl methyl ether, stabilized (see     68.......................................  DOT-4B150, without brazed
 Note 5).                                                                           seams; DOT-4BA225 without
                                                                                    brazed seams; DOT-4BW225;
                                                                                    DOT-3A150; DOT-3AA150; DOT-
                                                                                    3B1800; DOT-3E1800.
----------------------------------------------------------------------------------------------------------------
Note 1 to paragraph (a)(2): ``Filling density'' means the percent ratio of the weight of gas in a packaging to
  the weight of water that the container will hold at 16 [deg]C (60 [deg]F). (1 lb of water = 27.737 in\3\ at 60
  [deg]F.).
Note 2 to paragraph (a)(2): Cylinders purchased after Oct. 1, 1944, for the transportation of chlorine must
  contain no aperture other than that provided in the neck of the cylinder for attachment of a valve equipped
  with an approved pressure relief device. Cylinders purchased after Nov. 1, 1935, and filled with chlorine may
  not contain over 68.04 kg (150 lb) of gas.
Note 4 to paragraph (a)(2): Special carbon dioxide mining devices containing a heating element and filled with
  not over 2.72 kg (6 lb) of carbon dioxide may be filled to a density of not over 85 percent, provided the
  cylinder is made of steel with a calculated bursting pressure in excess of 39000 psig, fitted with a frangible
  disc that will operate at not over 57 percent of that pressure, and is able to withstand a drop of 10 feet
  when striking crosswise on a steel rail while under a pressure of at least 3000 psig. Such devices must be
  shipped in strong boxes or must be wrapped in heavy burlap and bound by 12-gauge wire with the wire completely
  covered by friction tape. Wrapping must be applied so as not to interfere with the functioning of the
  frangible disc pressure relief device. Shipments must be described as ``liquefied carbon dioxide gas (mining
  device)'' and marked, labeled, and certified as prescribed for liquefied carbon dioxide.
Note 5 to paragraph (a)(2): All parts of valve and pressure relief devices in contact with contents of cylinders
  must be of a metal or other material, suitably treated if necessary, that will not cause formation of any
  acetylides.

[[Page 85419]]

 
Note 7 to paragraph (a)(2): Specification 3HT cylinders for aircraft use only, having a maximum service life of
  24 years. Authorized only for nonflammable gases. Cylinders must be equipped with pressure relief devices of
  the frangible disc type that meet the requirements of Sec.   173.301(f). Each frangible disc must have a rated
  bursting pressure that does not exceed 90 percent of the minimum required test pressure of the cylinder. Discs
  with fusible metal backing are not permitted. Cylinders may be offered for transportation only when packaged
  in accordance with Sec.   173.301(a)(9).
Note 8 to paragraph (a)(2): See Sec.   173.301(a)(9).
Note 9 to paragraph (a)(2): When used for shipment of flammable gases, the internal volume of a specification 39
  cylinder must not exceed 75 cubic inches.
Note 10 to paragraph (a)(2): Each valve outlet must be sealed by a threaded cap or a threaded solid plug.
Note 11 to paragraph (a)(2): Must meet the valve and cleaning requirements in Sec.   173.302(b).
Note 12 to paragraph (a)(2): For an insecticide gas that is nontoxic and nonflammable, see Sec.   173.305(c).
Note 13 to paragraph (a)(2): For a refrigerant or dispersant gas that is nontoxic and nonflammable, see Sec.
  173.304(d).

    (3) A DOT 39 cylinder shall be equipped with a pressure relief 
device as defined by the commodity in CGA S-1.1, excluding paragraph 
9.1.1 (IBR; see Sec.  171.7 of this subchapter). If the commodity is 
not listed in CGA S-1.1, a CG-7 pressure relief valve must be used.
* * * * *
    (d) * * *
    (3) * * *
    (i) DOT 3, 3A, 3AA, 3B, 3E, 3AL, 4B, 4BA, 4B240ET, 4BW, 4E, or 39 
cylinders. The internal volume of a Specification 39 cylinder must not 
exceed 75 cubic inches. Shipments of flammable gases in DOT 3AL 
cylinders are authorized only when transported by motor vehicle, rail 
car, or cargo-only aircraft.
* * * * *

0
14. In Sec.  173.306, revise paragraph (g) to read as follows:


Sec.  173.306   Limited quantities of compressed gases.

* * * * *
    (g) Water pump system tank. Water pump system tanks pre-charged at 
time of manufacture with compressed air or limited quantities of 
nitrogen or helium to not over 275.79 kPa gauge pressure (40 psig) for 
single-trip shipment to installation sites are excepted from labeling, 
and the specification packaging requirements of this subchapter when 
shipped under the following conditions. In addition, shipments of these 
tanks are not subject to the placarding requirements of subpart F of 
part 172 of this subchapter, and not subject to parts 174 (except Sec.  
174.24) and 177 (except Sec.  177.817) of this subchapter.
    (1) The tank must be of steel or composite construction, with heads 
concave to pressure, having a rated water capacity not exceeding 455 L 
(120 gallons) and with an outside diameter not exceeding 61 cm (24 
inches). These tanks may be operated in ambient air temperatures of up 
to 49 [deg]C (120 [deg]F) with a maximum working pressure not less than 
75 psig and not greater than 150 psig. Safety relief devices are not 
required.
    (2) Each tank must be pneumatically tested to the manufacturer's 
specified maximum working pressure. The test pressure must be 
permanently marked on the tank. In any case, the pneumatic test must 
not be conducted to a pressure exceeding 150 psig.
    (3) The stress at prescribed pressure for steel tanks must not 
exceed 20,000 psig (or 25,000 psig for deep-draw steel), using the 
formula:

S = Pd/2t

Where:
S = wall stress in psi;
P = prescribed pressure for the tank is at least the manufacturer's 
rated maximum working pressure or three (3) times the pre-charged 
pressure at 21.1 [deg]C (70 [deg]F), whichever is greater;
d = inside diameter in inches; and
t = minimum wall thickness, in inches.

    (4) For steel and composite tanks, the burst pressure must be at 
least six (6) times the pre-charge pressure at 21.1 [deg]C (70 [deg]F) 
or three (3) times the manufacturer's specified maximum working 
pressure, whichever is greater.
    (5) Each tank must be over-packed in a strong outer packaging in 
conformance with Sec.  173.301(h).
    (6) Transportation is limited to motor vehicle, railcar, and 
vessel. Transportation by aircraft is not authorized.
* * * * *

0
15. In Sec.  173.309, revise the introductory text to read as follows:


Sec.  173.309   Fire extinguishers.

    This section applies to portable fire extinguishers for manual 
handling and operation, fire extinguishers for installation in 
aircraft, fire extinguishers for installation as part of a fire 
suppression system, and large fire extinguishers. Fire extinguishers 
for installation as part of a fire suppression system include cylinders 
charged with either a compressed gas and an extinguishing agent or a 
gas which comprises the sole fire extinguishing agent in the system. A 
fire extinguisher does not include cylinders pressurized with a gas for 
purposes of expelling a separately stored extinguishing agent in the 
fire suppression system. Large fire extinguishers include fire 
extinguishers mounted on wheels for manual handling; fire extinguishing 
equipment or machinery mounted on wheels or wheeled platforms or units 
transported similar to (small) trailers; and fire extinguishers 
composed of a non-rollable pressure drum and equipment, and handled, 
for example, by fork lift or crane when loaded or unloaded. Cylinders 
filled with a compressed gas whose purpose is to expel a separately 
stored extinguishing agent may not be transported under this section 
when offered for transportation or transported apart from a suppression 
system.
* * * * *

0
16. In Sec.  173.312, revise paragraph (b)(1) to read as follows:


Sec.  173.312   Requirements for shipment of MEGCs.

* * * * *
    (b) * * *
    (1) A MEGC may not be filled above its marked maximum permissible 
gross mass. Additionally, MEGCs must be filled in accordance with the 
following:
    (i) A MEGC being filled with non-liquefied (permanent) compressed 
gas may not be filled to a pressure greater than the lowest marked 
working pressure of any cylinder (pressure receptacle).
    (ii) An MEGC being filled with a liquefied compressed gas must have 
each pressure receptacle filled separately by weight and must be filled 
by a means to ensure that only one pressure receptacle is filled at a 
time.
    (iii) The filling density for UN pressure receptacles may not 
exceed the values in accordance with Sec.  173.304b(b).
* * * * *


Sec.  173.323   [AMENDED]

0
17. In Sec.  173.323(b)(2), immediately following the words ``Pamphlet 
C-14'' in the last sentence, add the phrase ``(IBR, see Sec.  171.7 of 
this subchapter)''.

PART 178--SPECIFICATIONS FOR PACKAGINGS

0
18. The authority citation for part 178 continues to read as follows:

    Authority: 49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97.


[[Page 85420]]



0
19. In Sec.  178.35, add paragraph (f)(8) to read as follows:


Sec.  178.35   General requirements for specification cylinders.

* * * * *
    (f) * * *
    (8) Tare weight or mass weight, and water capacity marking. DOT-
specification 4B, 4BA, 4BW, and 4E cylinders used in liquefied 
compressed gas service manufactured after December 28, 2022, must be 
marked with the tare weight or mass weight. Additionally, the cylinder 
must be permanently marked with the water capacity. The owner of the 
cylinder must ensure it is marked with the following information, as 
applicable:
    (i) Tare weight. The tare weight for a cylinder 25 pounds or less 
at the time of manufacture, with a lower tolerance of 3 percent and an 
upper tolerance of 1 percent; or for a cylinder exceeding 25 pounds at 
the time of manufacture, with a lower tolerance of 2 percent and an 
upper tolerance of 1 percent. The tare weight marking must be the 
actual weight of the fully assembled cylinder, including the valve(s) 
and other permanently affixed appurtenances. Removable protective 
cap(s) or cover(s) must not be included in the cylinder tare weight. 
Tare weight shall be abbreviated ``TW''; or
    (ii) Mass weight. The mass weight for a cylinder 25 pounds or less 
at the time of manufacture, with a lower tolerance of 3 percent and an 
upper tolerance of 1 percent; or the mass weight marking for a cylinder 
exceeding 25 pounds at the time of manufacture, with a lower tolerance 
of 2 percent and an upper tolerance of 1 percent. The mass weight 
marking must be the actual weight of the fully assembled cylinder, 
excluding valve(s) and removable protective cap(s) or cover(s). Mass 
weight shall be abbreviated ``MW''; and
    (iii) Water capacity. The water capacity for a cylinder 25 pounds 
water capacity or less, with a tolerance of minus 1 percent and no 
upper tolerance; or for a cylinder exceeding 25 pounds water capacity, 
with a tolerance of minus 0.5 percent and no upper tolerance. The 
marked water capacity of the cylinder must be the capacity of the 
cylinder at the time of manufacture. Water capacity shall be 
abbreviated ``WC''.
* * * * *

0
20. In Sec.  178.36, revise paragraph (i) to read as follows:


Sec.  178.36   Specification 3A and 3AX seamless steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of \5/3\ times 
service pressure.
    (3) The minimum test pressure must be maintained for at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and previous to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent, volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
* * * * *

0
21. In Sec.  178.37, revise paragraph (i) to read as follows:


Sec.  178.37   Specification 3AA and 3AAX seamless steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of \5/3\ times 
service pressure.
    (3) The minimum test pressure must be maintained for at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and previous to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent, volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
* * * * *

0
22. In Sec.  178.38, revise paragraph (i) to read as follows:


Sec.  178.38   Specification 3B seamless steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
defined in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Cylinders must be tested as follows:
    (i) Each cylinder to at least two (2) times its service pressure; 
or
    (ii) One (1) cylinder out of each lot of 200 or fewer to at least 
three (3) times its service pressure. When one (1) cylinder out of each 
lot of 200 or less is tested to at least 3 times service pressure, the 
balance of the lot must be pressure tested by the proof pressure, 
water-jacket or direct expansion test method as prescribed in CGA C-1. 
The cylinders must be subjected to at least 2 times service pressure 
and show no defect. If, due to failure of the test apparatus or 
operator error, the test pressure cannot be maintained, the test may be 
repeated in accordance with CGA C-1 5.7.2 or 7.1.2, as appropriate. 
Determination of expansion properties is not required.
    (3) When each cylinder is tested to the minimum test pressure, the 
minimum test pressure must be maintained at least 30 seconds and 
sufficiently longer to ensure complete expansion. Any internal pressure 
applied after heat-treatment and previous to the official test may not 
exceed 90 percent of the test pressure. If, due to failure of the test 
apparatus or operator error, the test pressure cannot be maintained, 
the test may be repeated in accordance with CGA C-1, section 5.7.2.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *

0
23. In Sec.  178.39, revise paragraph (i) to read as follows:


Sec.  178.39   Specification 3BN seamless nickel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure

[[Page 85421]]

indicating devices must be accurate within the parameters defined in 
CGA C-1.
    (2) Each cylinder must be tested to a minimum of at least two (2) 
times its service pressure.
    (3) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and previous to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *

0
24. In Sec.  178.42, revise paragraph (f) to read as follows:


Sec.  178.42   Specification 3E seamless steel cylinders.

* * * * *
    (f) Pressure testing. Cylinders must be tested as follows:
    (1) One cylinder out of each lot of 500 or fewer must be subjected 
to a hydrostatic test pressure of 6,000 psig or higher.
    (2) The cylinder referred to in paragraph (f)(1) of this section 
must burst at a pressure higher than 6,000 psig without fragmenting or 
otherwise showing lack of ductility, or must hold a pressure of 12,000 
psig for 30 seconds without bursting. In which case, it must be 
subjected to a flattening test without cracking to six times wall 
thickness between knife edges, wedge shaped 60 degree angle, rounded 
out to a \1/2\ inch radius. The inspector's report must be suitably 
changed to show results of latter alternate and flattening test. The 
testing equipment must be calibrated as prescribed in CGA C-1 (IBR, see 
Sec.  171.7 of this subchapter). All testing equipment and pressure 
indicating devices must be accurate within the parameters defined in 
CGA C-1.
    (3) The remaining cylinders of the lot must be pressure tested by 
the proof pressure water-jacket or direct expansion test method as 
prescribed in CGA C-1. Cylinders must be examined under pressure of at 
least 3,000 psig and not to exceed 4,500 psig and show no defect. 
Cylinders tested at a pressure in excess of 3,600 psig must burst at a 
pressure higher than 7,500 psig when tested as specified in paragraph 
(f)(2) of this section. The pressure must be maintained for at least 30 
seconds and sufficiently longer to ensure complete examination. The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1. If, due to failure of the 
test apparatus or operator error, the test pressure cannot be 
maintained, the test may be repeated in accordance with CGA C-1 5.7.2 
or 7.1.2, as appropriate. Determination of expansion properties is not 
required.
* * * * *

0
25. In Sec.  178.44, revise paragraph (i) to read as follows:


Sec.  178.44   Specification 3HT seamless steel cylinders for aircraft 
use.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to minimum of \5/3\ times service 
pressure.
    (3) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and previous to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *

0
26. In Sec.  178.45, revise paragraph (g) to read as follows:


Sec.  178.45   Specification 3T seamless steel cylinder.

* * * * *
    (g) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to minimum of \5/3\ times service 
pressure.
    (3) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *

0
27. In Sec.  178.46, revise paragraph (g) to read as follows:


Sec.  178.46   Specification 3AL seamless aluminum cylinders.

* * * * *
    (g) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) The minimum test pressure must be the greater of the following:
    (i) 450 psig regardless of service pressure;
    (ii) Two (2) times the service pressure for cylinders having 
service pressure less than 500 psig; or
    (iii) \5/3\ times the service pressure for cylinders having a 
service pressure of 500 psig or greater.
    (3) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2, however, if a second failure to maintain the test 
pressure occurs the cylinder being tested must be rejected.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *

0
28. In Sec.  178.47, revise paragraph (j) to read as follows:


Sec.  178.47   Specification 4DS welded stainless steel cylinders for 
aircraft use.

* * * * *

[[Page 85422]]

    (j) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of at least two (2) 
times its service pressure.
    (3) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent volumetric expansion may not exceed 10 percent of the 
total volumetric expansion at test pressure.
    (5) The cylinder must then be inspected. Any wall thickness lower 
than that required by paragraph (f) of this section must be cause for 
rejection. Bulges and cracks must be cause for rejection. Welded joint 
defects exceeding requirements of paragraph (k) of this section are 
cause for rejection.
* * * * *

0
29. Revise Sec.  178.50 to read as follows:


Sec.  178.50  Specification 4B welded or brazed steel cylinders.

    (a) Type, size, pressure, and application. A DOT 4B is a welded or 
brazed steel cylinder with longitudinal seams that are forged lap-
welded or brazed and with water capacity (nominal) not over 1,000 
pounds and a service pressure of at least 150 but not over 500 psig. 
Cylinders closed in by spinning process are not authorized.
    (b) Steel. Open-hearth, electric or basic oxygen process steel of 
uniform quality must be used. Content percent may not exceed the 
following: Carbon, 0.25; phosphorus, 0.045; sulphur, 0.050. The 
cylinder manufacturer must maintain a record of intentionally added 
alloying elements.
    (c) Identification of material. Pressure-retaining materials must 
be identified by any suitable method that does not compromise the 
integrity of the cylinder. Plates and billets for hotdrawn cylinders 
must be marked with the heat number.
    (d) Manufacture. Cylinders must be manufactured using equipment and 
processes adequate to ensure that each cylinder produced conforms to 
the requirements of this subpart. No defect is permitted that is likely 
to weaken the finished cylinder appreciably. A reasonably smooth and 
uniform surface finish is required. Exposed bottom welds on cylinders 
over 18 inches long must be protected by footrings. Welding procedures 
and operators must be qualified in conformance with CGA C-3 (IBR, see 
Sec.  171.7 of this subchapter). Seams must be made as follows:
    (1) Brazing materials. Brazing materials must be by copper brazing, 
by copper alloy brazing, or by silver alloy brazing. Copper alloy 
composition must be: Copper, 95 percent minimum; Silicon, 1.5 percent 
to 3.85 percent; Manganese, 0.25 percent to 1.10 percent.
    (2) Brazed circumferential seams. Heads attached by brazing must 
have a driving fit with the shell, unless the shell is crimped, 
swedged, or curled over the skirt or flange of the head, and be 
thoroughly brazed until complete penetration by the brazing material of 
the brazed joint is secured. Depth of brazing of the joint must be at 
least four (4) times the minimum thickness of shell metal.
    (3) Welded circumferential seams. Circumferential seams are 
permitted by the welding process.
    (4) Longitudinal seams in shells. Longitudinal seams must be a 
forged lap joint design. When brazed, the plate edge must be lapped at 
least eight (8) times the thickness of the plate, laps being held in 
position, substantially metal to metal, by riveting or electric spot-
welding; brazing must be done by using a suitable flux and by placing 
brazing material on one side of seam and applying heat until this 
material shows uniformly along the seam of the other side.
    (e) Welding or brazing. Only the attachment of neckrings, 
footrings, handles, bosses, pads, and valve protection rings to the 
tops and bottoms of cylinders by welding or brazing is authorized. 
Attachments and the portion of the cylinder to which they are attached 
must be made of weldable steel, the carbon content of which may not 
exceed 0.25 percent except in the case of 4130X steel, which may be 
used with proper welding procedure.
    (f) Wall thickness. The wall thickness of the cylinder must comply 
with the following requirements:
    (1) For cylinders with outside diameters over 6 inches, the minimum 
wall thickness must be 0.090 inch. In any case, the minimum wall 
thickness must be such that calculated wall stress at minimum test 
pressure (paragraph (i)(4) of this section) may not exceed the 
following values:
    (i) 24,000 psig for cylinders without longitudinal seam.
    (ii) 22,800 psig for cylinders having copper brazed or silver alloy 
brazed longitudinal seam.
    (iii) 18,000 psig for cylinders having forged lapped welded 
longitudinal seam.
    (2) Calculation must be made by the formula:

S = [P(1.3D\2\ + 0.4d\2\)]/(D\2\ - d\2\)

Where:
S = wall stress in psig;
P = minimum test pressure prescribed for water jacket test or 450 
psig whichever is the greater;
D = outside diameter in inches; and
d = inside diameter in inches.

    (g) Heat treatment. Cylinder heads, bodies or the completed 
cylinder, formed by drawing or pressing, must be uniformly and properly 
heat treated by an applicable method shown in table 1 of appendix A of 
this part before tests.
    (h) Opening in cylinders. Openings in cylinders must comply with 
the following:
    (1) Any opening must be placed on other than a cylindrical surface.
    (2) Each opening in a spherical type of cylinder must be provided 
with a fitting, boss, or pad of weldable steel securely attached to the 
cylinder by fusion welding.
    (3) Each opening in a cylindrical type cylinder, except those for 
pressure relief devices, must be provided with a fitting, boss, or pad, 
securely attached to container by brazing or by welding.
    (4) If threads are used, they must comply with the following:
    (i) Threads must be clean cut, even without checks, and tapped to 
gauge.
    (ii) Taper threads must be of a length not less than as specified 
for American Standard taper pipe threads.
    (iii) Straight threads, must have at least four (4) engaged 
threads, must have tight fit and a calculated shear strength at least 
ten (10) times the test pressure of the cylinder; gaskets are required 
for straight threads and must be of sufficient quality to prevent 
leakage.
    (iv) A brass fitting may be brazed to the steel boss or flange on 
cylinders used as component parts of handheld fire extinguishers.
    (5) The closure of a fitting, boss, or pad must be adequate to 
prevent leakage.
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows: (1) Lot testing. (i) At least one (1) 
cylinder randomly selected out of each lot of 200 or fewer must be

[[Page 85423]]

tested by the water jacket or direct expansion method as prescribed in 
CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The testing 
equipment must be calibrated as prescribed in CGA C-1. All testing 
equipment and pressure indicating devices must be accurate within the 
parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of 2 times service 
pressure.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in the lot must 
be tested by the proof pressure, water-jacket, or direct expansion test 
method as prescribed in CGA C-1. The minimum test pressure must be 
maintained for the specific timeframe and the testing equipment must be 
calibrated as prescribed in CGA C-1. Further, all testing equipment and 
pressure indicating devices must be accurate within the parameters 
defined in CGA C-1. If, due to failure of the test apparatus or 
operator error, the test pressure cannot be maintained, the test may be 
repeated in accordance with CGA C-1, sections 5.7.2 or 7.1.2, as 
appropriate. Determination of expansion properties is not required.
    (ii) Each cylinder must be tested to a minimum of at least two (2) 
times service pressure and show no defect.
    (j) Mechanical test. A mechanical test must be conducted to 
determine yield strength, tensile strength, elongation as a percentage, 
and reduction of area of material as a percentage as follows:
    (1) Testing is required on two (2) specimens removed from one (1) 
cylinder, or part thereof, heat-treated as required, as illustrated in 
appendix A to this subpart. For lots of 30 or fewer, mechanical tests 
are authorized to be made on a ring at least 8 inches long removed from 
each cylinder and subjected to the same heat treatment as the finished 
cylinder.
    (2) Specimens must comply with the following:
    (i) When a cylinder wall is \3/16\ inch thick or less, one the 
following gauge lengths is authorized: A gauge length of 8 inches with 
a width not over 1\1/2\ inches, a gauge length of 2 inches with a width 
not over 1\1/2\ inches, or a gauge length at least twenty-four (24) 
times the thickness with a width not over six (6) times the thickness.
    (ii) The specimen, exclusive of grip ends, may not be flattened. 
Grip ends may be flattened to within one inch of each end of the 
reduced section.
    (iii) When the size of a cylinder does not permit securing straight 
specimens, the specimens may be taken in any location or direction and 
may be straightened or flattened cold, by pressure only, not by blows. 
When specimens are taken and prepared using this method, the 
inspector's report must show detailed information regarding such 
specimens in connection with the record of mechanical tests.
    (iv) Heating of a specimen for any purpose is not authorized.
    (3) The yield strength in tension must be the stress corresponding 
to a permanent strain of 0.2 percent of the gauge length. The following 
conditions apply:
    (i) The yield strength must be determined by either the ``offset'' 
method or the ``extension under load'' method as prescribed in ASTM E 8 
(IBR, see Sec.  171.7 of this subchapter).
    (ii) In using the ``extension under load'' method, the total strain 
(or ``extension under load'') corresponding to the stress at which the 
0.2 percent permanent strain occurs may be determined with sufficient 
accuracy by calculating the elastic extension of the gauge length under 
appropriate load and adding thereto 0.2 percent of the gauge length. 
Elastic extension calculations must be based on an elastic modulus of 
30,000,000. In the event of controversy, the entire stress-strain 
diagram must be plotted and the yield strength determined from the 0.2 
percent offset.
    (iii) For strain measurement, the initial strain reference must be 
set while the specimen is under a stress of 12,000 psig, and strain 
indicator reading must be set at the calculated corresponding strain.
    (iv) Cross-head speed of the testing machine may not exceed \1/8\ 
inch per minute during yield strength determination.
    (v) The yield strength must not exceed 73 percent of the tensile 
strength.
    (k) Elongation. Mechanical test specimens must show at least a 40 
percent elongation for a 2-inch gauge length or at least 20 percent in 
other cases. However, elongation percentages may be reduced numerically 
by 2 percent for 2-inch specimens, and by 1 percent in other cases, for 
each 7,500 psig increase of tensile strength above 50,000 psig. The 
tensile strength may be incrementally increased by four increments of 
7,500 psig for a maximum total of 30,000 psig.
    (l) Flattening test--(1) Cylinders. After pressure testing, a 
flattening test must be performed on one cylinder taken at random out 
of each lot of 200 or fewer by placing the cylinder between wedge-
shaped knife edges having a 60 degree included angle, rounded to a 
half-inch radius. The longitudinal axis of the cylinder must be at a 
90-degree angle to knife edges during the test. For lots of 30 or 
fewer, flattening tests are authorized to be performed on a ring of at 
least 8 inches long removed from each cylinder and subjected to the 
same heat treatment as the finished cylinder.
    (2) Pipes. When cylinders are constructed of lap welded pipe, an 
additional flattening test is required, without evidence of cracking, 
up to six (6) times the wall thickness. In such case, the rings (crop 
ends) removed from each end of the pipe, must be tested with the weld 
45 [deg]F or less from the point of greatest stress.
    (m) Acceptable results for flattening tests. There must be no 
evidence of cracking of the sample when it is flattened between flat 
plates to no more than six (6) times the wall thickness. If this test 
fails, one additional sample from the same lot may be taken. If this 
second sample fails, the entire lot must be rejected.
    (n) Rejected cylinders. Reheat treatment is authorized for a 
rejected cylinder in accordance with this paragraph (n). After reheat 
treatment, a cylinder must pass all prescribed tests in this section to 
be considered acceptable. Repair of brazed seams by brazing and welded 
seams by welding is authorized. For cylinders with an outside diameter 
of less than or equal to six (6) inches, welded seam repairs greater 
than one (1) inch in length shall require reheat treatment of the 
cylinder. For cylinders greater than an outside diameter of 6 inches, 
welded seam repairs greater than three (3) inches in length shall 
require reheat treatment.
    (o) Markings. (1) Markings must be as required as in Sec.  178.35 
and in addition must be stamped plainly and permanently in any of the 
following locations on the cylinder:
    (i) On shoulders and top heads whose wall thickness is not less 
than 0.087-inch thick;
    (ii) On side wall adjacent to top head for side walls which are not 
less than 0.090 inch thick;
    (iii) On a cylindrical portion of the shell that extends beyond the 
recessed bottom of the cylinder, constituting an integral and non-
pressure part of the cylinder;

[[Page 85424]]

    (iv) On a metal plate attached to the top of the cylinder or 
permanent part thereof; sufficient space must be left on the plate to 
provide for stamping at least six retest dates; the plate must be at 
least \1/16\-inch thick and must be attached by welding, or by brazing. 
The brazing rod must melt at a temperature of 1100 [deg]F. Welding or 
brazing must be along all the edges of the plate;
    (v) On the neck, neckring, valve boss, valve protection sleeve, or 
similar part permanently attached to the top of the cylinder; or
    (vi) On the footring permanently attached to the cylinder, provided 
the water capacity of the cylinder does not exceed 30 pounds.
    (2) Embossing the cylinder head or sidewall is not permitted.

0
30. Revise Sec.  178.51 to read as follows:


Sec.  178.51   Specification 4BA welded or brazed steel cylinders.

    (a) Type, size, pressure, and application. A DOT 4BA cylinder is a 
cylinder, either spherical or cylindrical design, with a water capacity 
of 1,000 pounds or less and a service pressure range of 225 to 500 
psig. Closures made by the spinning process are not authorized.
    (1) Spherical type cylinder designs are permitted to have only one 
circumferentially welded seam.
    (2) Cylindrical type cylinder designs must be of circumferentially 
welded or brazed construction; longitudinally brazed or silver-soldered 
seams are also permitted.
    (b) Steel. The steel used in the construction of the cylinder must 
be as specified in table 1 of appendix A to this part. The cylinder 
manufacturer must maintain a record of intentionally added alloying 
elements.
    (c) Identification of material. Pressure-retaining material must be 
identified by any suitable method that does not compromise the 
integrity of the cylinder. Plates and billets for hotdrawn cylinders 
must be marked with the heat number.
    (d) Manufacture. Cylinders must be manufactured using equipment and 
processes adequate to ensure that each cylinder produced conforms to 
the requirements of this subpart. No defect is permitted that is likely 
to weaken the finished cylinder appreciably. A reasonably smooth and 
uniform surface finish is required. Exposed bottom welds on cylinders 
over 18 inches long must be protected by footrings.
    (1) Seams must be made as follows:
    (i) Minimum thickness of heads and bottoms must be not less than 90 
percent of the required thickness of the side wall.
    (ii) Circumferential seams must be made by welding or by brazing. 
Heads attached by brazing must have a driving fit with the shell unless 
the shell is crimped, swedged, or curled over the skirt or flange of 
the head and must be thoroughly brazed until complete penetration by 
the brazing material of the brazed joint is secured. Depth of brazing 
from end of the shell must be at least four (4) times the thickness of 
shell metal.
    (iii) Longitudinal seams in shells must be made by copper brazing, 
copper alloy brazing, or by silver alloy brazing. Copper alloy 
composition must be: Copper 95 percent minimum, Silicon 1.5 percent to 
3.85 percent, Manganese 0.25 percent to 1.10 percent. The melting point 
of the silver alloy brazing material must be in excess of 1,000 [deg]F. 
The plate edge must be lapped at least eight times the thickness of 
plate, laps being held in position, substantially metal to metal, by 
riveting or by electric spot-welding. Brazing must be done by using a 
suitable flux and by placing brazing material on one side of seam and 
applying heat until this material shows uniformly along the seam of the 
other side. Strength of longitudinal seam: Copper brazed longitudinal 
seam must have strength at least \3/2\ times the strength of the steel 
wall.
    (2) Welding procedures and operators must be qualified in 
conformance with CGA C-3 (IBR, see Sec.  171.7 of this subchapter).
    (e) Welding or brazing. Welding or brazing of any attachment or 
opening to the heads of cylinders is permitted provided the carbon 
content of the steel does not exceed 0.25 percent except in the case of 
4130 x steel, which may be used with proper welding procedure.
    (f) Wall thickness. The minimum wall thickness of the cylinder must 
meet the following conditions:
    (1) For any cylinder with an outside diameter of greater than 6 
inches, the minimum wall thickness is 0.078 inch. In any case, the 
minimum wall thickness must be such that the calculated wall stress at 
the minimum test pressure may not exceed the lesser value of any of the 
following:
    (i) The value shown in table 1 of appendix A to this part, for the 
material under consideration;
    (ii) One-half of the minimum tensile strength of the material 
determined as required in paragraph (j) of this section;
    (iii) 35,000 psig; or
    (iv) Further provided that wall stress for cylinders having copper 
brazed longitudinal seams may not exceed 95 percent of any of the above 
values. Measured wall thickness may not include galvanizing or other 
protective coating.
    (2) Cylinders that are cylindrical in shape must have the wall 
stress calculated by the formula:

S = [P(1.3D\2\ + 0.4d\2\)]/(D\2\ - d\2\)

Where:
S = wall stress in psig;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches; and
d = inside diameter in inches.

    (3) Cylinders that are spherical in shape must have the wall stress 
calculated by the formula:

S = PD/4tE
Where:
S = wall stress in psig;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches;
t = minimum wall thickness in inches;
E = 0.85 (provides 85 percent weld efficiency factor which must be 
applied in the circumferential weld area and heat affected zones 
which zone must extend a distance of 6 times wall thickness from 
center line of weld); and
E = 1.0 (for all other areas).

    (4) For a cylinder with a wall thickness less than 0.100 inch, the 
ratio of tangential length to outside diameter may not exceed 4.1.
    (g) Heat treatment. Cylinders must be heat treated in accordance 
with the following requirements:
    (1) Each cylinder must be uniformly and properly heat treated prior 
to test by the applicable method shown in table 1 of appendix A to this 
part. Heat treatment must be accomplished after all forming and welding 
operations, except that when brazed joints are used, heat treatment 
must follow any forming and welding operations, but may be done before, 
during or after the brazing operations (see paragraph (m) of this 
section for weld repairs).
    (2) Heat treatment is not required after the welding or brazing of 
weldable low carbon parts to attachments of similar material which have 
been previously welded or brazed to the top or bottom of cylinders and 
properly heat treated, provided such subsequent welding or brazing does 
not produce a temperature in excess of 400 [deg]F in any part of the 
top or bottom material.
    (h) Openings in cylinders. Openings in cylinders must comply with 
the following requirements:
    (1) Any opening must be placed on other than a cylindrical surface.
    (2) Each opening in a spherical type cylinder must be provided with 
a fitting, boss, or pad of weldable steel securely attached to the 
container by fusion welding.
    (3) Each opening in a cylindrical type cylinder must be provided 
with a fitting,

[[Page 85425]]

boss, or pad, securely attached to container by brazing or by welding.
    (4) If threads are used, they must comply with the following:
    (i) Threads must be clean-cut, even, without checks and tapped to 
gauge.
    (ii) Taper threads must be of a length not less than that specified 
for American Standard taper pipe threads.
    (iii) Straight threads, having at least 4 engaged threads, must 
have a tight fit and a calculated shear strength of at least 10 times 
the test pressure of the cylinder. Gaskets, adequate to prevent 
leakage, are required.
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder randomly selected 
out of each lot of 200 or fewer must be tested by water jacket or 
direct expansion method as prescribed in CGA C-1 (IBR, see Sec.  171.7 
of this subchapter). The testing equipment must be calibrated as 
prescribed in CGA C-1. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
    (ii) The selected cylinder must be tested to a minimum of two (2) 
times service pressure.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in the lot must 
be tested by the proof pressure, water-jacket, or direct expansion test 
method as prescribed in CGA C-1. The minimum test pressure must be 
maintained for the specific timeframe and the testing equipment must be 
calibrated as prescribed in CGA C-1. Further, all testing equipment and 
pressure indicating devices must be accurate within the parameters 
defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure and show no defect. If, due to failure of the test 
apparatus or operator error, the test pressure cannot be maintained, 
the test may be repeated in accordance with CGA C-1 5.7.2 or 7.1.2, as 
appropriate. Determination of expansion properties is not required.
    (j) Mechanical test. (1) A mechanical test must be conducted to 
determine yield strength, tensile strength, elongation as a percentage, 
and reduction of area of material as a percentage, as follows:
    (i) Cylinders. Testing is required on two (2) specimens removed 
from one cylinder or part thereof taken at random out of each lot of 
200 or fewer. Samples must be removed after heat treatment as 
illustrated in appendix A to this subpart.
    (ii) Spheres. Testing is required on two (2) specimens removed from 
the sphere or flat representative sample plates of the same heat of 
material taken at random from the steel used to produce the spheres. 
Samples (including plates) must be taken from each lot of 200 or fewer. 
The flat steel from which two specimens are to be removed must receive 
the same heat treatment as the spheres themselves. Samples must be 
removed after heat treatment as illustrated in appendix A to this 
subpart.
    (2) Specimens must comply with the following:
    (i) When a cylinder wall is \3/16\ inch thick or less, one the 
following gauge lengths is authorized: A gauge length of 8 inches with 
a width not over 1\1/2\ inches, a gauge length of 2 inches with a width 
not over 1\1/2\ inches, or a gauge length at least twenty-four (24) 
times the thickness with a width not over six (6) times the thickness.
    (ii) The specimen, exclusive of grip ends, may not be flattened. 
Grip ends may be flattened to within one inch of each end of the 
reduced section.
    (iii) When size of the cylinder does not permit securing straight 
specimens, the specimens may be taken in any location or direction and 
may be straightened or flattened cold, by pressure only, not by blows. 
When specimens are so taken and prepared, the inspector's report must 
show with the record of physical tests detailed information in regard 
to such specimens.
    (iv) Heating of a specimen for any purpose is not authorized.
    (3) The yield strength in tension must be the stress corresponding 
to a permanent strain of 0.2 percent of the gauge length. The following 
conditions apply:
    (i) The yield strength must be determined by either the ``offset'' 
method or the ``extension under load'' method as prescribed in ASTM E 8 
(IBR, see Sec.  171.7 of this subchapter).
    (ii) In using the ``extension under load'' method, the total strain 
(or ``extension under load''), corresponding to the stress at which the 
0.2 percent permanent strain occurs may be determined with sufficient 
accuracy by calculating the elastic extension of the gauge length under 
appropriate load and adding thereto 0.2 percent of the gauge length. 
Elastic extension calculations must be based on an elastic modulus of 
30,000,000. In the event of controversy, the entire stress-strain 
diagram must be plotted and the yield strength determined from the 0.2 
percent offset.
    (iii) For strain measurement, the initial strain reference must be 
set while the specimen is under a stress of 12,000 psig, and the strain 
indicator reading must be set at the calculated corresponding strain.
    (k) Elongation. Mechanical test specimens must show at least a 40 
percent elongation for a 2-inch gauge length or at least 20 percent in 
other cases. However, elongation percentages may be reduced numerically 
by 2 percent for 2-inch specimens, and by 1 percent in other cases, for 
each 7,500 psig increase of tensile strength above 50,000 psig. The 
tensile strength may be incrementally increased by four increments of 
7,500 psig for a maximum total of 30,000 psig.
    (l) Tests of welds. Except for brazed seams, welds must be tested 
as follows:
    (1) Tensile test. A specimen must be removed from one cylinder of 
each lot of 200 or fewer, or welded test plate. The welded test plate 
must be of one of the heats in the lot of 200 or fewer which it 
represents, in the same condition and approximately the same thickness 
as the cylinder wall except that in no case must it be of a lesser 
thickness than that required for a quarter size Charpy impact specimen. 
The weld must be made by the same procedures and subjected to the same 
heat treatment as the major weld on the cylinder. The specimen must be 
taken from across the major seam and must be prepared and tested in 
conformance with and must meet the requirements of CGA C-3. Should this 
specimen fail to meet the requirements, one additional specimen must be 
taken from two additional cylinders or welded test plates from the same 
lot and tested. If either of these latter two specimens fail to meet 
the requirements, the entire lot represented must be rejected.
    (2) Guided bend test. A root bend test specimen must be removed 
from the cylinder or welded test plate that was used for the tensile 
test specified in paragraph (l)(1) of this section. The specimen must 
be taken from across the circumferential seam and must be prepared and 
tested in conformance with and must meet the requirements of CGA C-3. 
Should this specimen fail to meet the requirements, one additional

[[Page 85426]]

specimen must be taken from two additional cylinders or welded test 
plates from the same lot and tested. If either of these latter two 
specimens fail to meet the requirements, the entire lot represented 
must be rejected.
    (3) Alternate guided-bend test. This test may be used and must be 
as required by CGA C-3. The specimen must be bent until the elongation 
at the outer surface, adjacent to the root of the weld, between the 
lightly scribed gage lines a to b, must be at least 20 percent, except 
that this percentage may be reduced for steels having a tensile 
strength in excess of 50,000 psig, as provided in paragraph (k) of this 
section. Should the specimen fail to meet the requirements, one 
additional specimen must be taken from two additional cylinders or 
welded test plates from the same lot and tested. If any of these latter 
two specimens fail to meet the requirements, the entire lot represented 
must be rejected.
    (m) Rejected cylinders. Reheat treatment is authorized for a 
rejected cylinder in accordance with this paragraph (m). After reheat, 
a cylinder must pass all prescribed tests in this section to be 
acceptable. Repair of brazed seams by brazing and welded seams by 
welding is considered authorized. For cylinders with an outside 
diameter of less than or equal to six (6) inches, welded seam repairs 
greater than one (1) inch in length shall require reheat treatment of 
the cylinder. For cylinders greater than an outside diameter of six (6) 
inches, welded seam repairs greater than three (3) inches in length 
shall require reheat treatment.
    (n) Markings. (1) Markings must be as required in Sec.  178.35 and 
in addition must be stamped plainly and permanently in one of the 
following locations on the cylinder:
    (i) On shoulders and top heads whose wall thickness is not less 
than 0.087 inch thick;
    (ii) On side wall adjacent to top head for side walls not less than 
0.090 inch thick;
    (iii) On a cylindrical portion of the shell that extends beyond the 
recessed bottom of the cylinder constituting an integral and non-
pressure part of the cylinder;
    (iv) On a plate attached to the top of the cylinder or permanent 
part thereof; sufficient space must be left on the plate to provide for 
stamping at least six retest dates; the plate must be at least \1/16\ 
inch thick and must be attached by welding, or by brazing at a 
temperature of at least 1100 [deg]F., throughout all edges of the 
plate;
    (v) On the neck, neckring, valve boss, valve protection sleeve, or 
similar part permanently attached to the top of the cylinder; or
    (vi) On the footring permanently attached to the cylinder, provided 
the water capacity of the cylinder does not exceed 30 pounds.
    (2) [Reserved]

0
31. In Sec.  178.53, revise paragraph (h) to read as follows:


Sec.  178.53   Specification 4D welded steel cylinders for aircraft 
use.

* * * * *
    (h) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one cylinder selected at random out 
of each lot of 200 or fewer must be tested by water-jacket or direct 
expansion as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this 
subchapter). The testing equipment must be calibrated as prescribed in 
CGA C-1. All testing equipment and pressure indicating devices must be 
accurate within the parameters defined in CGA C-1.
    (ii) The selected cylinder must be tested to a minimum of three (3) 
times service pressure.
    (iii) The minimum test pressure must be maintained be maintained at 
least 30 seconds and sufficiently longer to ensure complete expansion. 
Any internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in each lot must 
be tested by the proof pressure water-jacket or direct expansion test 
method as prescribed in CGA C-1. The minimum test pressure must be 
maintained for the specific timeframe and the testing equipment must be 
calibrated as prescribed in CGA C-1. Further, all testing equipment and 
pressure indicating devices must be accurate within the parameters 
defined in CGA C-1. Determination of expansion properties is not 
required.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure and show no defect. If, due to failure of the test 
apparatus or operator error, the test pressure cannot be maintained, 
the test may be repeated in accordance with CGA C-1 5.7.2 or 7.1.2, as 
appropriate.
    (3) Alternative volumetric expansion testing. As an alternative to 
the testing prescribed in paragraphs (h)(1) and (2) of this section, 
every cylinder may be volumetrically expansion tested by the water 
jacket or direct expansion test method. The testing equipment must be 
calibrated as prescribed in CGA C-1. All testing equipment and pressure 
indicating devices must be accurate within the parameters defined in 
CGA C-1.
    (i) Each cylinder must be tested to a minimum of at least two (2) 
times its service pressure.
    (ii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and previous to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iii) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *

0
32. In Sec.  178.55, revise paragraph (i) to read as follows:


Sec.  178.55  Specification 4B240ET welded or brazed cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder selected at random 
out of each lot of 200 or fewer must be tested by water-jacket or 
direct expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7 
of this subchapter). The testing equipment must be calibrated as 
prescribed in CGA C-1. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in each lot must 
be tested by the proof pressure water-jacket or direct expansion test 
method as prescribed in

[[Page 85427]]

CGA C-1. The minimum test pressure must be maintained for the specific 
timeframe and the testing equipment must be calibrated as prescribed in 
CGA C-1. All testing equipment and pressure indicating devices must be 
accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure and show no defect. If, due to failure of the test 
apparatus or operator error, the test pressure cannot be maintained, 
the test may be repeated in accordance with CGA C-1 5.7.2 or 7.1.2. 
Determination of expansion properties is not required.
    (3) Burst testing. (i) For purposes of burst testing, each 1,000 
cylinders or fewer successively produced each day constitutes a lot. 
All cylinders of a lot must be of identical size, construction heat 
treatment, finish, and quality.
    (ii) One cylinder must be selected from each lot and be 
hydrostatically pressure tested to destruction. If this cylinder bursts 
below five (5) times the service pressure, then two additional 
cylinders from the same lot as the previously tested cylinder must be 
selected and subjected to this test. If either of these cylinders fails 
by bursting below five (5) times the service pressure then the entire 
lot must be rejected. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
* * * * *

0
33. In Sec.  178.56, revise paragraph (i) to read as follows:


Sec.  178.56  Specification 4AA480 welded steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder selected at random 
out of each lot of 200 or fewer must be tested by water-jacket or 
direct expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7 
of this subchapter). The testing equipment must be calibrated as 
prescribed in CGA C-1. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
    (ii) The selected cylinder must be tested to a minimum of two (2) 
times service pressure.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (v) If the selected cylinder fails, then two (2) additional 
specimens must be selected at random from the same lot and subjected to 
the prescribed testing. If either of these fails the test, then each 
cylinder in that lot must be tested as prescribed in paragraph (i)(l) 
of this section.
    (2) Pressure testing. (i) The remaining cylinders in each lot must 
be tested by the proof pressure, water-jacket, or direct expansion test 
method as prescribed in CGA C-1. The minimum test pressure must be 
maintained for the specific timeframe and the testing equipment must be 
calibrated as prescribed in CGA C-1. Further, all testing equipment and 
pressure indicating devices must be accurate within the parameters 
defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure and show no defect. A cylinder showing a defect must 
be rejected unless it may be requalified under paragraph (m) of this 
section. If, due to failure of the test apparatus or operator error, 
the test pressure cannot be maintained, the test may be repeated in 
accordance with CGA C-1 5.7.2 or 7.1.2, as appropriate. Determination 
of expansion properties is not required.
* * * * *

0
34. In Sec.  178.57, revise paragraph (i) to read as follows:


Sec.  178.57  Specification 4L welded insulated cylinders.

* * * * *
    (i) Pressure testing. Each cylinder, before insulating and 
jacketing, must successfully withstand a pressure test as follows:
    (1) The cylinder must be tested by the proof pressure, water-
jacket, or direct expansion test method as prescribed in CGA C-1 (IBR; 
see Sec.  171.7 of this subchapter). The testing equipment must be 
calibrated as prescribed in CGA C-1. All testing equipment and pressure 
indicating devices must be accurate within the parameters defined in 
CGA C-1.
    (2) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (3) The minimum test pressure must be maintained at least 30 
seconds. Any internal pressure applied after heat-treatment and prior 
to the official test may not exceed 90 percent of the test pressure. 
If, due to failure of the test apparatus or operator error, the test 
pressure cannot be maintained, the test may be repeated in accordance 
with CGA C-1 5.7.2 or 7.1.2. Determination of expansion properties is 
not required.
    (4) There must be no evidence of leakage, visible distortion or 
other defect.
* * * * *

0
35. In Sec.  178.58, revise paragraph (i) to read as follows:


Sec.  178.58  Specification 4DA welded steel cylinders for aircraft 
use.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as 
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (3) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (4) Permanent volumetric expansion may not exceed 10 percent of the 
total volumetric expansion at test pressure.
* * * * *

0
36. In Sec.  178.59, revise paragraph (h) to read as follows:


Sec.  178.59  Specification 8 steel cylinders with porous fillings for 
acetylene.

* * * * *
    (h) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder selected at random 
out of each lot of 200 or fewer must be tested by water-jacket or 
direct expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7 
of this subchapter). The testing equipment must be calibrated as 
prescribed in CGA C-1. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
    (ii) The selected cylinder must be tested to a minimum of 750 psig.

[[Page 85428]]

    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (v) If the selected cylinder passes the volumetric expansion test, 
each remaining cylinder in the lot must be pressure tested in 
accordance with paragraph (h)(2) of this section. If the selected 
cylinder fails, each cylinder in the lot must be tested by water-jacket 
or direct expansion method as prescribed in CGA C-1 at 750 psig. Each 
cylinder with a permanent expansion that does not exceed 10% is 
acceptable.
    (2) Pressure testing. (i) If the selected cylinder passes the 
water-jacket or direct expansion test, the remaining cylinders in each 
lot must be pressure tested by the proof pressure, water-jacket or 
direct expansion test method as prescribed in CGA C-1. The minimum test 
pressure must be maintained for the specific timeframe and the testing 
equipment must be calibrated as prescribed in CGA C-1. Further, all 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested between 500 and 600 psig and show 
no defect. If, due to failure of the test apparatus or operator error, 
the test pressure cannot be maintained, the test may be repeated in 
accordance with CGA C-1 section 5.7.2 or 7.1.2, as appropriate. 
Determination of expansion properties is not required.
* * * * *

0
37. In Sec.  178.60, revise paragraph (j) to read as follows:


Sec.  178.60  Specification 8AL steel cylinders with porous fillings 
for acetylene.

* * * * *
    (j) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder selected at random 
out of each lot of 200 or less must be tested by water-jacket or direct 
expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this 
subchapter). The testing equipment must be calibrated as prescribed in 
CGA C-1. All testing equipment and pressure indicating devices must be 
accurate within the parameters defined in CGA C-1.
    (ii) The selected cylinder must be tested to a minimum of 750 psig.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (v) If the selected cylinder passes the volumetric expansion test, 
each remaining cylinder in the lot must be pressure tested in 
accordance with paragraph (h)(2) of this section. If the selected 
cylinder fails, each cylinder in the lot must be tested by water-jacket 
or direct expansion method as prescribed in CGA C-1 at 750 psig. Each 
cylinder with a permanent expansion that does not exceed 10% is 
acceptable.
    (2) Pressure testing. (i) If the selected cylinder passes the 
water-jacket or direct expansion test, the remaining cylinders in each 
lot must be pressure tested by the proof pressure water-jacket or 
direct expansion test method as prescribed in CGA C-1. The minimum test 
pressure must be maintained for the specific timeframe and the testing 
equipment must be calibrated as prescribed in CGA C-1. Further, all 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested between 500 and 600 psig and show 
no defect. If, due to failure of the test apparatus or operator error, 
the test pressure cannot be maintained, the test may be repeated in 
accordance with CGA C-1 section 5.7.2 or 7.1.2, as appropriate. 
Determination of expansion properties is not required.
* * * * *

0
38. Revise Sec.  178.61 to read as follows:


Sec.  178.61  Specification 4BW welded steel cylinders with electric-
arc welded seam.

    (a) Type, size, pressure, and application. A DOT 4BW cylinder has a 
spherical or cylindrical design, a water capacity of 1,000 pounds or 
less, and a service pressure range of 225 to 500 psig. Closures made by 
the spinning process are not authorized.
    (1) Spherical designs are permitted to have only one 
circumferentially electric-arc welded seam.
    (2) Cylindrical designs must be of circumferentially welded 
electric-arc construction; longitudinally electric-arc welded seams are 
permitted.
    (b) Steel. (1) The steel used in the construction of the cylinder 
must be as specified in table 1 of appendix A to this part. The 
cylinder manufacturer must maintain a record of intentionally added 
alloying elements.
    (2) Material for heads must meet the requirements of paragraph 
(b)(1) of this section or be open hearth, electric or basic oxygen 
carbon steel of uniform quality. Content percent may not exceed the 
following: Carbon 0.25, Manganese 0.60, Phosphorus 0.045, Sulfur 0.050. 
Heads must be hemispherical or ellipsoidal in shape with a maximum 
ratio of 2:1. If low carbon steel is used, the thickness of such heads 
must be determined by using a maximum wall stress of 24,000 psi in the 
formula described in paragraph (f)(2) of this section.
    (c) Identification of material. Pressure-retaining materials must 
be identified by any suitable method that does not compromise the 
integrity of the cylinder. Plates and billets for hotdrawn cylinders 
must be marked with the heat number.
    (d) Manufacture. Cylinders must be manufactured using equipment and 
processes adequate to ensure that each cylinder produced conforms to 
the requirements of this subpart and the following:
    (1) No defect is permitted that is likely to weaken the finished 
cylinder appreciably. A reasonably smooth and uniform surface is 
required. Exposed bottom welds on cylinders over 18 inches long must be 
protected by footrings. Minimum thickness of heads may not be less than 
90 percent of the required thickness of the sidewall. Heads must be 
concave to pressure.
    (2) Circumferential seams must be by electric-arc welding. Joints 
must be butt with one member offset (joggle butt) or with a lap joint. 
Joints must have a minimum overlap of at least four (4) times nominal 
sheet thickness.
    (3) Longitudinal electric-arc welded seams (in shells) must be of 
the butt welded type. Welds must be made by a machine process including 
automatic feed and welding guidance mechanisms. Longitudinal seams must 
have complete joint penetration, and must be free from undercuts, 
overlaps or abrupt ridges or valleys. Misalignment of mating butt edges 
may not exceed \1/6\ inch of nominal sheet thickness or \1/32\ inch 
whichever is less. All joints with nominal sheet thickness up to and 
including \1/8\ inch must be tightly butted. When nominal sheet 
thickness is

[[Page 85429]]

greater than \1/8\ inch, the joint must be gapped with maximum distance 
equal to one-half the nominal sheet thickness or \1/32\ inch whichever 
is less. Joint design, preparation, and fit-up must be such that 
requirements of this paragraph (d) are satisfied.
    (4) Welding procedures and operators must be qualified in 
accordance with CGA C-3 (IBR, see Sec.  171.7 of this subchapter).
    (5)(i) Welds of the cylinders must be subjected to radioscopic or 
radiographic examination as follows:
    (ii) Radioscopy or radiography must be in conformance with CGA C-3 
(IBR; see Sec.  171.7 of this subchapter). Maximum joint efficiency 
will be 1.0 when each longitudinal seam is examined completely. Maximum 
joint efficiency will be 0.90 when one cylinder from each lot of 50 
consecutively welded cylinders is spot examined. In addition, one out 
of the first five cylinders welded following a shutdown of welding 
operations exceeding four hours must be spot examined. Spot 
radiographs, when required, must be made of a finished welded cylinder 
and must include the circumferential weld for 2 inches in both 
directions from the intersection of the longitudinal and 
circumferential welds and include at least 6 inches of the longitudinal 
weld. Maximum joint efficiency of 0.75 will be permissible without 
radiography or radioscopy. When fluoroscopic examination is used, 
permanent film records need not be retained. Circumferential welds need 
not be examined, except as part of spot examination.
    (e) Welding of attachments. The attachment to the tops and bottoms 
only of cylinders by welding of neckrings, footrings, handles, bosses, 
pads and valve protection rings is authorized provided that such 
attachments and the portion of the container to which they are attached 
are made of weldable steel, the carbon content of which may not exceed 
0.25 percent.
    (f) Wall thickness. (1) For outside diameters over 6 inches the 
minimum wall thickness must be 0.078 inch. In any case, the minimum 
wall thickness must be such that the wall stress calculated by the 
formula listed in paragraph (f)(2) of this section may not exceed the 
lesser value of any of the following:
    (i) The value referenced in paragraph (b) of this section for the 
particular material under consideration.
    (ii) One-half of the minimum tensile strength of the material 
determined as required in paragraph (j) of this section.
    (iii) 35,000 psig.
    (2) Stress must be calculated by the following formula:

S = [2P(1.3D\2\ + 0.4d\2\)]/[E(D\2\ - d\2\)]

Where:
S = wall stress, psig;
P = service pressure, psig;
D = outside diameter, inches;
d = inside diameter, inches; and
E = joint efficiency of the longitudinal seam (from paragraph (d) of 
this section).

    (3) For a cylinder with a wall thickness less than 0.100 inch, the 
ratio of tangential length to outside diameter may not exceed 4 to 1 
(4:1).
    (g) Heat treatment. Cylinders must be heat treated in accordance 
with the following requirements:
    (1) Each cylinder must be uniformly and properly heat treated prior 
to test by the applicable method referenced in table 1 of appendix A to 
this part. Heat treatment must be accomplished after all forming and 
welding operations, except that when brazed joints are used, heat 
treatment must follow any forming and welding operations, but may be 
done before, during or after the brazing operations (see paragraph (n) 
of this section for weld repairs).
    (2) Heat treatment is not required after welding of weldable low-
carbon parts to attachments of similar material which have been 
previously welded to the top or bottom of cylinders and properly heat 
treated, provided such subsequent welding does not produce a 
temperature in excess of 400 [deg]F in any part of the top or bottom 
material.
    (h) Openings in cylinders. Openings in cylinders must comply with 
the following requirements:
    (1) All openings must be in heads or bases.
    (2) Each opening in a spherical-type cylinder must be provided with 
a fitting, boss, or pad of weldable steel securely attached to the 
cylinder by fusion welding.
    (3) Each opening in a cylindrical-type cylinder must be provided 
with a fitting, boss, or pad securely attached to the cylinder by 
welding.
    (4) If threads are used, they must comply with the following:
    (i) Threads must be clean cut, even, without checks, and tapped to 
gauge.
    (ii) Taper threads must be of length not less than as specified for 
American Standard Taper Pipe Threads.
    (iii) Straight threads, having at least four (4) engaged threads, 
must have a tight fit and calculated shear strength at least ten (10) 
times the test pressure of the cylinder. Gaskets, adequate to prevent 
leakage, are required.
    (iv) A brass fitting may be brazed to the steel boss or flange on 
cylinders used as component parts of handheld fire extinguishers.
    (i) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder randomly selected 
out of each lot of 200 or fewer must be tested by the water-jacket or 
direct expansion method as prescribed in CGA C-1 (IBR, see Sec.  171.7 
of this subchapter). The testing equipment must be calibrated as 
prescribed in CGA C-1. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
    (ii) Each selected cylinder must be tested to a minimum of two (2) 
times service pressure.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in each lot must 
be pressure tested by the proof pressure, water-jacket or direct 
expansion test method as prescribed in CGA C-1. The minimum test 
pressure must be maintained for the specific timeframe and the testing 
equipment must be calibrated as prescribed in CGA C-1. Further, all 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure and show no defect. If, due to failure of the test 
apparatus or operator error, the test pressure cannot be maintained, 
the test may be repeated in accordance with CGA C-1 5.7.2 or 7.1.2, as 
appropriate. Determination of expansion properties is not required.
    (3) Burst testing. One finished cylinder selected at random out of 
each lot of 500 or less successively produced must be hydrostatically 
tested to four (4) times service pressure without bursting. All testing 
equipment and pressure indicating devices must be accurate within the 
parameters defined in CGA C-1.
    (j) Mechanical tests. Mechanical tests must be conducted to 
determine yield strength, tensile strength, elongation as a percentage, 
and reduction of area of material as a percentage, as follows:
    (1) Specimens must be taken from one cylinder after heat treatment 
as

[[Page 85430]]

illustrated in appendix A to this subpart, chosen at random from each 
lot of 200 or fewer, as follows:
    (i) One specimen must be taken longitudinally from the body section 
at least 90 degrees away from the weld.
    (ii) One specimen must be taken from either head on a cylinder when 
both heads are made of the same material. However, if the two heads are 
made of differing materials, a specimen must be taken from each head.
    (iii) If due to welded attachments on the top head there is 
insufficient surface from which to take a specimen, it may be taken 
from a representative head of the same heat treatment as the test 
cylinder.
    (2) Specimens must conform to the following:
    (i) When a cylinder wall is \3/16\ inch thick or less, one the 
following gauge lengths is authorized: A gauge length of 8 inches with 
a width not over 1\1/2\ inches, a gauge length of 2 inches with a width 
not over 1\1/2\ inches, or a gauge length at least twenty-four (24) 
times the thickness with a width not over six (6) times the thickness.
    (ii) The specimen, exclusive of grip ends, may not be flattened. 
Grip ends may be flattened to within 1 inch of each end of the reduced 
section.
    (iii) When size of the cylinder does not permit securing straight 
specimens, the specimens may be taken in any location or direction and 
may be straightened or flattened cold, by pressure only, not by blows. 
When specimens are taken, and prepared in this manner, the inspector's 
report must show, in connection with the record of physical tests, 
detailed information in regard to such specimens.
    (iv) Heating of a specimen for any purpose is not authorized.
    (3) The yield strength in tension must be the stress corresponding 
to a permanent strain of 0.2 percent of the gauge length. The following 
conditions apply:
    (i) The yield strength must be determined by either the ``off-set'' 
method or the ``extension under load'' method as prescribed in ASTM E 8 
(IBR, see Sec.  171.7 of this subchapter).
    (ii) In using the ``extension under load'' method, the total strain 
(or ``extension under load''), corresponding to the stress at which the 
0.2-percent permanent strain occurs may be determined with sufficient 
accuracy by calculating the elastic extension of the gauge length under 
appropriate load and adding thereto 0.2 percent of the gauge length. 
Elastic extension calculations must be based on an elastic modulus of 
30,000,000. In the event of controversy, the entire stress-strain 
diagram must be plotted and the yield strength determined from the 0.2-
percent offset.
    (iii) For strain measurement, the initial strain reference must be 
set while the specimen is under a stress of 12,000 psig, and the strain 
indicator reading must be set at the calculated corresponding strain.
    (iv) Cross-head speed of the testing machine may not exceed \1/8\ 
inch per minute during yield strength determination.
    (k) Elongation. Mechanical test specimens must show at least a 40 
percent elongation for a 2-inch gauge length or at least 20 percent in 
other cases. However, elongation percentages may be reduced numerically 
by 2 percent for 2-inch specimens, and by 1 percent in other cases, for 
each 7,500 psi increase of tensile strength above 50,000 psig. The 
tensile strength may be incrementally increased by four increments of 
7,500 psig for a maximum total of 30,000 psig.
    (l) Tests of welds. Welds must be subjected to the following tests:
    (1) Tensile test. A specimen must be removed from one cylinder of 
each lot of 200 or fewer. The specimen must be taken from across the 
longitudinal seam and must be prepared and tested in conformance with 
the requirements of CGA C-3 (IBR, see Sec.  171.7 of this subchapter).
    (2) Guided bend test. A root bend test specimen must be removed 
from the cylinder or welded test plate used for the tensile test 
specified in paragraph (m)(1) of this section. Specimens must be taken 
from across the longitudinal seam and must be prepared and tested in 
conformance with the requirements of CGA C-3. If the specimen fails to 
meet the requirements, one specimen each must be taken from two 
additional cylinders or welded test plates from the same lot as the 
previously tested cylinder or added test plate and tested. If either of 
these latter two specimens fails to meet the requirements, the entire 
lot represented must be rejected.
    (3) Alternate guided bend test. This test may be used and must be 
as required by CGA C-3. The specimen must be bent until the elongation 
at the outer surface, adjacent to the root of the weld, between the 
lightly scribed gauge lines a to b, must be at least 20 percent, except 
that this percentage may be reduced for steels having a tensile 
strength in excess of 50,000 psig, as provided in paragraph (k) of this 
section. Should this specimen fail to meet the requirements, one 
additional specimen must be taken from two additional cylinders or 
welded test plates from the same lot and tested as the previously 
tested cylinder or added test plate. If either of these latter two 
specimens fails to meet the requirements, the entire lot represented 
must be rejected.
    (m) Rejected cylinders. (1) Unless otherwise stated, if a sample 
cylinder or specimen taken from a lot of cylinders fails the prescribed 
test, then two additional specimens must be selected from the same lot 
and subjected to the prescribed test. If either of these fails the 
test, then the entire lot must be rejected.
    (2) Reheat treatment of rejected cylinders. Reheat treatment is 
authorized for a rejected cylinder in accordance with this paragraph 
(m)(2). After reheat treatment, a cylinder must pass all prescribed 
tests in this section to be considered acceptable. Repair of welded 
seams by welding is authorized. For cylinders less than or equal to an 
outside diameter of 6 inches, welded seam repairs greater than 1 inch 
in length shall require reheat treatment of the cylinder. For cylinders 
greater than an outside diameter of 6 inches, welded seam repairs 
greater than 3 inches in length shall require reheat treatment.
    (n) Markings. (1) Markings must be as required in Sec.  178.35 and 
in addition must be stamped plainly and permanently in one of the 
following locations on the cylinder:
    (i) On shoulders and top heads whose wall thickness is not less 
than 0.087 inch thick.
    (ii) On side wall adjacent to top head for side walls not less than 
0.090 inch thick.
    (iii) On a cylindrical portion of the shell that extends beyond the 
recessed bottom of the cylinder constituting an integral and non-
pressure part of the cylinder.
    (iv) On a plate attached to the top of the cylinder or permanent 
part thereof; sufficient space must be left on the plate to provide for 
stamping at least six retest dates; the plate must be at least \1/16\-
inch thick and must be attached by welding at a temperature of 1,100 
[deg]F, throughout all edges of the plate.
    (v) On the neck, neckring, valve boss, valve protection sleeve, or 
similar part permanently attached to the top of the cylinder.
    (vi) On the footring permanently attached to the cylinder, provided 
the water capacity of the cylinder does not exceed 30 pounds.
    (2) Embossing the cylinder head or side wall is not permitted.
    (o) Inspector's report. In addition to the information required by 
Sec.  178.35, the inspector's report must indicate the type and amount 
of radiography.


0
39. In Sec.  178.65, revise paragraph (f) to read as follows:

[[Page 85431]]

Sec.  178.65   Specification 39 non-reusable (non-refillable) 
cylinders.

* * * * *
    (f) Pressure testing. (1) Each cylinder must be proof pressure 
tested as prescribed in CGA C-1 (IBR, see Sec.  171.7 of this 
subchapter). The minimum test pressure must be maintained for the 
specific timeframe and the testing equipment must be calibrated as 
prescribed in CGA C-1. All testing equipment and pressure indicating 
devices must be accurate within the parameters defined in CGA C-1.
    (i) The leakage test must be conducted by submersion under water or 
by some other method that will be equally sensitive.
    (ii) If the cylinder leaks, evidences visible distortion or 
evidences any other defect while under test, it must be rejected (see 
paragraph (h) of this section).
    (iii) If, due to failure of the test apparatus or operator error, 
the test pressure cannot be maintained, the test may be repeated in 
accordance with CGA, C-1 section 7.1.2.
    (2) One cylinder taken from the beginning of each lot, and one from 
each 1,000 or less successively produced within the lot thereafter, 
must be hydrostatically tested to destruction. The testing equipment 
must be calibrated as prescribed in CGA C-1. All testing equipment and 
pressure indicating devices must be accurate within the parameters 
defined in CGA C-1. The entire lot must be rejected (see paragraph (h) 
of this section) if:
    (i) A failure occurs at a gage pressure less than 2.0 times the 
test pressure;
    (ii) A failure initiates in a braze or a weld or the heat affected 
zone thereof;
    (iii) A failure is other than in the sidewall of a cylinder 
longitudinal with its long axis; or
    (iv) In a sphere, a failure occurs in any opening, reinforcement, 
or at a point of attachment.
    (3) A ``lot'' is defined as the quantity of cylinders successively 
produced per production shift (not exceeding 10 hours) having identical 
size, design, construction, material, heat treatment, finish, and 
quality.
* * * * *


0
40. In Sec.  178.68:
0
a. Revise paragraphs (b), (e), (h), (j) introductory text, (j)(1), and 
(k) through (m);
0
b. Redesignate paragraph (n) as paragraph (o); and
0
c. Add new paragraph (n).
    The revisions and addition read as follows:


Sec.  178.68   Specification 4E welded aluminum cylinders.

* * * * *
    (b) Authorized material. (1) The cylinder must be constructed of 
aluminum of uniform quality. The following chemical analyses are 
authorized:

            Table 1 to Paragraph (b)(1)--Authorized Materials
------------------------------------------------------------------------
                                          Chemical  analysis--limits in
              Designation                         percent 5154
------------------------------------------------------------------------
Iron plus silicon.....................  0.45 maximum.
Copper................................  0.10 maximum.
Manganese.............................  0.10 maximum.
Magnesium.............................  3.10/3.90.
Chromium..............................  0.15/0.35.
Zinc..................................  0.20 maximum.
Titanium..............................  0.20 maximum.
Others, each..........................  0.05 maximum.
Others, total.........................  0.15 maximum.
Aluminum..............................  remainder.
------------------------------------------------------------------------

    (2) The aluminum used in the construction of the cylinder must be 
as specified in Table 1 to paragraph (b)(1) of this section. Analyses 
must regularly be made only for the elements specifically mentioned in 
the table. If, however, the presence of other elements is indicated in 
the course of routine analysis, further analysis should be made to 
determine conformance with the limits specified for other elements. The 
cylinder manufacturer must maintain a record of intentionally added 
alloying elements.
* * * * *
    (e) Welding. The attachment to the tops and bottoms only of 
cylinders by welding of neckrings, flanges, footrings, handles, bosses, 
pads, and valve protection rings is authorized. However, such 
attachments and the portion of the cylinder to which it is attached 
must be made of weldable aluminum alloys.
* * * * *
    (h) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Pressure test. All cylinders with a wall stress greater than 
18,000 psig must be tested by water-jacket or direct expansion method 
as prescribed in CGA C-1 (IBR, see Sec.  171.7 of this subchapter). The 
testing equipment must be calibrated as prescribed in CGA C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA C-1.
    (i) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (ii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure. If, due 
to failure of the test apparatus or operator error, the test pressure 
cannot be maintained, the test may be repeated in accordance with CGA 
C-1, section 5.7.2.
    (iii) Permanent volumetric expansion may not exceed 12 percent of 
the total volumetric expansion at test pressure.
    (2) Lot testing. (i) Cylinders with a wall stress of 18,000 psig or 
less may be lot tested. At least one (1) cylinder randomly selected out 
of each lot of 200 or less must be tested by the water-jacket or direct 
expansion method as prescribed in CGA C-1. The testing equipment must 
be calibrated as prescribed in CGA C-1. All testing equipment and 
pressure indicating devices must be accurate within the parameters 
defined in CGA C-1. If, due to failure of the test apparatus or 
operator error, the test pressure cannot be maintained, the test may be 
repeated in accordance with CGA C-1, section 5.7.2.
    (ii) Each selected cylinder must be tested to a minimum of two (2) 
times service pressure.
    (iii) The minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied after heat-treatment and prior to the 
official test may not exceed 90 percent of the test pressure.
    (iv) Permanent volumetric expansion may not exceed 12 percent of 
the total volumetric expansion at test pressure.
    (3) Pressure testing. (i) For cylinders with a wall stress of 
18,000 psig or less, the remaining cylinders of the lot must be 
pressure tested by the proof pressure, water-jacket, or direct 
expansion test method as defined in CGA C-1. The minimum test pressure 
must be maintained for the specific timeframe and the testing equipment 
must be calibrated as prescribed in CGA C-1. Further, all testing 
equipment and pressure indicating devices must be accurate within the 
parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times 
service pressure and show no defect. If, due to failure of the test 
apparatus or operator error, the test pressure cannot be maintained, 
the test may be repeated in accordance with CGA C-1 5.7.2 or 7.1.2, as 
appropriate. Determination of expansion properties is not required.
    (4) Burst testing. One (1) finished cylinder selected at random out 
of each lot of 1000 or less must be hydrostatically tested to four (4) 
times

[[Page 85432]]

service pressure without bursting. Inability to meet this requirement 
must result in rejection of the lot. All testing equipment and pressure 
indicating devices must be accurate within the parameters defined in 
CGA C-1.
* * * * *
    (j) Mechanical test. A mechanical test must be conducted to 
determine yield strength, tensile strength, elongation as a percentage, 
and reduction of area of material as a percentage as follows:
    (1) The test is required on two (2) specimens removed from one 
cylinder or part thereof as illustrated in appendix A to this subpart 
taken at random out of each lot of 200 or fewer.
* * * * *
    (k) Acceptable results for mechanical tests. An acceptable result 
of the mechanical test requires at least 7 percent and yield strength 
not over 80 percent of tensile strength.
    (l) Weld tests. Welds of the cylinder are required to pass the 
following tests successfully:
    (1) Reduced section tensile test. A specimen must be removed from 
the cylinder used for the mechanical tests specified in paragraph (j) 
of this section. The specimen must be taken from across the seam; edges 
must be parallel for a distance of approximately 2 inches on either 
side of the weld. The specimen must be fractured in tension. The actual 
breaking stress must be a minimum of 30,000 psi. The apparent breaking 
stress calculated on the minimum design wall thickness must be a 
minimum of two (2) times the stress calculated under paragraph (f)(2) 
of this section. If the specimen fails to meet the requirements, the 
lot must be rejected except that specimens may be taken from two (2) 
additional cylinders from the same lot as the previously tested 
specimens. If either of the latter specimens fails to meet 
requirements, the entire lot represented must be rejected.
    (2) Guided bend test. A bend test specimen must be removed from the 
cylinder used for the mechanical test specified in paragraph (j) of 
this section. The specimen must be taken across the circumferential 
seam, must be a minimum of 1\1/2\ inches wide, edges must be parallel 
and rounded with a file, and back-up strip, if used, must be removed by 
machining. The specimen must be tested as follows:
    (i) Standard guided bend test. The specimen must be bent to refusal 
in the guided bend test jig as illustrated in CGA C-3 (IBR, see Sec.  
171.7 of this subchapter). The root of the weld (inside surface of the 
cylinder) must be located away from the ram of the jig. The specimen 
must not show a crack or other open defect exceeding \1/8\ inch in any 
direction upon completion of the test. Should this specimen fail to 
meet the requirements, one additional specimen must be taken from two 
additional cylinders from the same lot and tested. If either of the 
latter specimens fails to meet requirements, the entire lot represented 
must be rejected.
    (ii) Alternate guided bend test. This test may be used as an 
alternate to the guided bend test. The test specimen must be in 
conformance with The Aluminum Association's ``Welding Aluminum: Theory 
and Practice, Fourth Edition, 2002'' (IBR, see Sec.  171.7 of this 
subchapter). If the specimen fails to meet the requirements, one 
additional specimen must be taken from two additional cylinders or 
welded test plates from the same lot and tested. If any of these latter 
two specimens fails to meet the requirements, the entire lot must be 
rejected.
    (m) Rejected cylinders. Repair of welded seams is authorized. 
Acceptable cylinders must pass all prescribed tests.
    (n) Markings. (1) Markings must be as required in Sec.  178.35 and 
in addition must be stamped plainly and permanently in one of the 
following locations on the cylinder:
    (i) On the neck, neckring, valve boss, valve protection sleeve, or 
similar part permanently attached to the top of the cylinder.
    (ii) On the footring permanently attached to the cylinder, provided 
the water capacity of the cylinder does not exceed 30 pounds.
    (2) Embossing the cylinder head or side wall is not permitted.
* * * * *

0
41. In Sec.  178.70, revise paragraph (d) to read as follows:


Sec.  178.70   Approval of UN pressure receptacles.

* * * * *
    (d) Modification of approved pressure receptacle design type. 
Modification of an approved UN (ISO) pressure receptacle design type is 
not authorized without the approval of the Associate Administrator. 
However, modification of an approved UN (ISO) pressure receptacle 
design type is authorized without an additional approval of the 
Associate Administrator provided the design modification is covered 
under the UN (ISO) standard for the design type. A manufacturer seeking 
modification of an approved UN (ISO) pressure receptacle design type 
may be required to submit design qualification test data to the 
Associate Administrator before production. An audit may be required as 
part of the process to modify an approval.
* * * * *

0
42. In Sec.  178.75, revise paragraphs (e)(3)(i) and (ii) and (f)(1) to 
read as follows:


Sec.  178.75   Specifications for MEGCs.

* * * * *
    (e) * * *
    (3) * * *
    (i) Two valves in series must be placed in an accessible position 
on each discharge and filling pipe. One of the valves may be a backflow 
prevention valve.
    (ii) The filling and discharge devices may be equipped to a 
manifold.
* * * * *
    (f) * * *
    (1) The size of the pressure relief devices: CGA S-1.1, excluding 
paragraph 9.1.1, (IBR, see Sec.  171.7 of this subchapter) must be used 
to determine the relief capacity of individual pressure receptacles.
* * * * *

PART 180--CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS

0
43. The authority citation for part 180 continues to read as follows:

    Authority: 49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97.


0
44. In Sec.  180.203:
0
a. Revise the definition for ``Commercially free of corrosive 
components;''
0
b. Remove the definitions ``Defect'' and ``Elastic expansion;''
0
c. Add definitions for ``Mobile unit'' and ``Over-pressurized'' in 
alphabetical order;
0
d. Remove the definition of ``Permanent expansion;''
0
e. Revise the definition for ``Proof pressure test;'' and
0
f. Remove the definitions of ``Rejected cylinder,'' ``Test pressure,'' 
``Total expansion,'' ``Visual inspection,'' and ``Volumetric expansion 
test.''
    The additions and revisions read as follows:


Sec.  180.203  Definitions.

* * * * *
    Commercially free of corrosive components means a hazardous 
material having a moisture content less than 55 ppm and free of 
components that will adversely react with the cylinder (e.g., chemical 
stress corrosion).
* * * * *
    Mobile unit means a vehicle specifically authorized under a RIN to 
carry out requalification operations

[[Page 85433]]

identified under the RIN within specified geographic areas away from 
the principle place of business. Mobile units must comply with the 
requirements outlined in the approval issuance letter from the 
Associate Administrator for Hazardous Materials Safety (see Sec.  
107.805 of subchapter A of this chapter).
* * * * *
    Over-pressurized means a condition in which the internal pressure 
applied to a cylinder has reached or exceeded the yield point of the 
cylinder.
* * * * *
    Proof pressure test means a liquid-based pressure test by interior 
pressurization without the determination of a cylinder's expansion.
* * * * *

0
45. In Sec.  180.205:
0
a. Revise paragraphs (c) introductory text and (d);
0
b. Add paragraphs (f)(5) and (6);
0
c. Revise paragraphs (g), (h)(3), and (i)(1)(viii);
0
d. Add paragraphs (i)(1)(ix) through (xi);
0
e. Revise paragraphs (i)(2) and (3); and
0
f. Add paragraph (j).
    The revisions and additions read as follows:


Sec.  180.205   General requirements for requalification of 
specification cylinders.

* * * * *
    (c) Periodic requalification of cylinders. Each cylinder bearing a 
DOT, CRC, BTC, or CTC specification marking must be requalified and 
marked as specified in the requalification table in Sec.  180.209(a) or 
requalified and marked by a facility registered by Transport Canada in 
accordance with the Transport Canada TDG Regulations (IBR, see Sec.  
171.7 of this subchapter). Each cylinder bearing both a TC 
specification marking and also marked with a corresponding DOT 
specification marking must be requalified and marked as specified in 
the requalification table in Sec.  180.209(a) or requalified and marked 
by a facility registered by Transport Canada in accordance with the 
Transport Canada TDG Regulations. Each cylinder bearing a DOT special 
permit (or exemption) number must be requalified and marked in 
conformance with this section and the terms of the applicable special 
permit (or exemption). Each cylinder bearing only a TC mark must be 
requalified and marked as specified in the Transport Canada TDG 
Regulations, except that registration with Transport Canada is not 
required and cylinders must be marked with the requalifier's DOT issued 
requalifier identification number. No cylinder may be filled with a 
hazardous material and offered for transportation in commerce unless 
that cylinder has been successfully requalified and marked in 
accordance with this subpart. A cylinder may be requalified at any time 
during or before the month and year that the requalification is due. 
However, a cylinder filled before the requalification becomes due may 
remain in service until it is emptied. A cylinder with a specified 
service life may not be refilled and offered for transportation after 
its authorized service life has expired.
* * * * *
    (d) Conditions requiring test and inspection of cylinders. Without 
regard to any other periodic requalification requirements, a cylinder 
must be tested and inspected in accordance with this section prior to 
further use if--
    (1) The cylinder shows evidence of dents, corrosion, cracked or 
abraded areas, leakage, or any other condition that might render it 
unsafe for use in transportation;
    (2) The cylinder has been in an accident and has been damaged to an 
extent that may adversely affect its lading retention capability;
    (3) The cylinder shows evidence of or is known to have thermal 
damage, or have been over-heated;
    (4) Except in association with an authorized repair, evidence of 
removal of wall thickness via grinding, sanding or other means; or
    (5) The Associate Administrator determines that the cylinder may be 
in an unsafe condition.
* * * * *
    (f) * * *
    (5) Except in association with an authorized repair, removal of 
wall thickness via grinding, sanding or other means is not permitted. 
Removal of paint or loose material to prepare the cylinder for 
inspection is permitted (e.g., shot blasting).
    (6) Chasing of cylinder threads to clean them is permitted, but 
removal of metal must not occur. Re-tapping of cylinder threads is not 
permitted, except by the original manufacturer, as provided in Sec.  
180.212.
* * * * *
    (g) Pressure test. (1) Unless otherwise provided, each cylinder 
required to be retested under this subpart must be retested by means 
suitable for measuring the expansion of the cylinder under pressure. 
Testing must be performed in accordance with CGA C-1 (except for 
paragraph 5.3.2.2, if the required accuracy of the pressure indicating 
device can be demonstrated by other recognized means such as 
calibration certificates) (IBR, see Sec.  171.7 of this subchapter).
    (2) The pressure indicating device and expansion indicating device 
must meet the resolution requirements of CGA C-1. Midpoint visual 
interpolation is allowed.
    (3) Each day before retesting, the retester shall confirm, by using 
a calibrated cylinder or other method authorized in writing by the 
Associate Administrator, that:
    (i) The pressure-indicating device, as part of the retest 
apparatus, is accurate within <plus-minus>1.0% of the prescribed test 
pressure of any cylinder tested that day. The pressure indicating 
device, itself, must be certified as having an accuracy of <plus-
minus>0.5%, or better, of its full range, and must permit readings of 
pressure from 90%-110% of the minimum prescribed test pressure of the 
cylinder to be tested. The accuracy of the pressure indicating device 
within the test system can be demonstrated at any point within 500 psig 
of the actual test pressure for test pressures at or above 3000 psig, 
or 10% of the actual test pressure for test pressures below 3000 psig.
    (ii) The expansion-indicating device, as part of the retest 
apparatus, meets the accuracy requirements of CGA C-1.
    (4) Test equipment must be verified each day before retesting as 
required in CGA C-1.
    (i) The retester must demonstrate calibration in conformance with 
this paragraph (g) to an authorized inspector on any day that it 
retests cylinders.
    (ii) A retester must maintain calibrated cylinder certificates in 
conformance with Sec.  180.215(b)(4).
    (5) A system check may be performed at or below 90% of test 
pressure prior to the retest. In the case of a malfunction of the test 
equipment or operator error, the test may be repeated in accordance 
with CGA C-1, section 5.7.1. This paragraph (g) does not authorize 
retest of a cylinder otherwise required to be condemned under paragraph 
(i) of this section.
    (h) * * *
    (3) Unless the cylinder is repaired or rebuilt in conformance with 
requirements in Sec.  180.211, it may not be filled with a hazardous 
material and offered for transportation where use of a specification 
packaging is required.
* * * * *
    (i) * * *
    (1) * * *
    (viii) For an aluminum or an aluminum-lined composite special 
permit cylinder, the cylinder is known to have been or shows evidence 
of having been overheated. Arc burns must be considered evidence of 
overheating.

[[Page 85434]]

    (ix) The cylinder is known to have been or shows evidence of having 
been over-pressurized.
    (x) For a cylinder with a specified service life, its authorized 
service life has expired.
    (xi) The cylinder has been stamped on the sidewall, except as 
provided in part 178 of this subchapter.
    (2) When a cylinder must be condemned, the requalifier must--
    (i) Communicate condemnation of the cylinder as follows:
    (A) Stamp a series of Xs over the DOT-specification number and the 
marked pressure or stamp ``CONDEMNED'' on the shoulder, top head, or 
neck using a steel stamp;
    (B) For composite cylinders, securely affix to the cylinder a label 
with the word ``CONDEMNED'' overcoated with epoxy near, but not 
obscuring, the original cylinder manufacturer's label; or
    (C) As an alternative to the stamping or labeling as described in 
this paragraph (i)(2), at the direction of the owner, the requalifier 
may render the cylinder incapable of holding pressure; and
    (ii) Notify the cylinder owner, in writing, that the cylinder is 
condemned and may not be filled with hazardous material and offered for 
transportation in commerce where use of a specification packaging is 
required.
    (3) No person may remove, obliterate, or alter the required 
condemnation communication of paragraph (i)(2) of this section.
    (j) Training materials. Training materials may be used for training 
persons who requalify cylinders using the volumetric expansion test 
method.

0
46. In Sec.  180.207, revise paragraphs (a)(3), (b)(2), (c) 
introductory text, (d) introductory text, and (d)(1) to read as 
follows:


Sec.  180.207   Requirements for requalification of UN pressure 
receptacles.

    (a) * * *
    (3) A pressure receptacle with a specified service life may not be 
requalified after its authorized service life has expired. A pressure 
receptacle with a specified service life may not be refilled and 
offered for transportation after its authorized service life has 
expired unless approval has been obtained in writing from the Associate 
Administrator.
    (b) * * *
    (2) Each pressure receptacle that fails requalification must be 
rejected or condemned in accordance with the applicable ISO 
requalification standard.
* * * * *
    (c) Requalification interval. Each UN pressure receptacle that 
becomes due for periodic requalification must be requalified at the 
interval specified in the following table before it is filled:
* * * * *
    (d) Requalification procedures. Each UN pressure receptacle must be 
requalified in conformance with the procedures contained in the 
following standards, as applicable. Furthermore, when a pressure test 
is performed on a UN pressure receptacle, the test must be a water 
jacket volumetric expansion test suitable for the determination of the 
cylinder expansion or a hydraulic proof pressure test. The test 
equipment must conform to the accuracy requirements in Sec.  
180.205(g). Alternative methods (e.g., acoustic emission) or 
requalification procedures may be performed if prior approval has been 
obtained in writing from the Associate Administrator.
    (1) Seamless steel: Each seamless steel UN pressure receptacle, 
including pressure receptacles exceeding 150 L capacity installed in 
MEGCs or in other service, must be requalified in accordance with ISO 
6406:2005(E) (IBR, see Sec.  171.7 of this subchapter). However, UN 
cylinders with a tensile strength greater than or equal to 950 MPa must 
be requalified by ultrasonic examination in accordance with ISO 
6406:2005(E). For seamless steel cylinders and tubes, the internal 
inspection and hydraulic pressure test may be replaced by a procedure 
conforming to ISO 16148:2016(E) (IBR, see Sec.  171.1).
* * * * *

0
47. In Sec.  180.209:
0
a. Remove and reserve paragraph (b)(1)(iii); and
0
b. Revise paragraphs (c), (e), (g), (j), and (l)(1).
    The revisions read as follows:


Sec.  180.209   Requirements for requalification of specification 
cylinders.

* * * * *
    (c) DOT 4-series cylinders. A DOT 4-series cylinder, except a 4L 
cylinder, that at any time shows evidence of a leak, internal or 
external corrosion, denting, bulging or rough usage to the extent that 
it is likely to be weakened appreciably, or that has lost 5 percent or 
more of its official tare weight must be requalified before being 
refilled and offered for transportation. (Refer to CGA C-6 or C-6.3 
(IBR, see Sec.  171.7 of this subchapter), as applicable, regarding 
cylinder weakening.) After testing, the actual tare weight must be 
recorded as the new tare weight on the test report and marked on the 
cylinder. The previous tare weight must be strike-lined through, but 
not obliterated.
* * * * *
    (e) Cylinders in non-corrosive gas service. A cylinder made in 
conformance with DOT Specifications 4B, 4BA, 4BW, or 4E protected 
externally by a suitable corrosion-resistant coating and used 
exclusively for non-corrosive gas that is commercially free from 
corroding components may be requalified by volumetric expansion testing 
every 12 years instead of every 5 years. As an alternative, the 
cylinder may be subjected to a proof pressure test at least two times 
the marked service pressure, but this latter type of test must be 
repeated every 10 years after expiration of the initial 12-year period. 
When subjected to a proof pressure test, as prescribed in CGA C-1 (IBR, 
see Sec.  171.7 of this subchapter), the cylinder must be carefully 
examined under test pressure and removed from service if a leak or 
defect is found.
* * * * *
    (g) Visual inspections. A cylinder conforming to a specification 
listed in the table in this paragraph (g) and used exclusively in the 
service indicated may, instead of a periodic hydrostatic test, be given 
a complete external visual inspection at the time periodic 
requalification becomes due. External visual inspection must be in 
conformance with CGA C-6 or C-6.3, as applicable. When this inspection 
is used instead of hydrostatic testing, subsequent inspections are 
required at five-year intervals after the first inspection. Inspections 
must be made only by persons holding a current RIN and the results 
recorded and maintained in conformance with Sec.  180.215. Records must 
include: Date of inspection (month and year); DOT-specification number; 
cylinder identification (registered symbol and serial number, date of 
manufacture, and owner); type of cylinder protective coating (including 
statement as to need of refinishing or recoating); conditions checked 
(e.g., leakage, corrosion, gouges, dents or digs in shell or heads, 
broken or damaged footring or protective ring or fire damage); and 
disposition of cylinder (returned to service, returned to cylinder 
manufacturer for repairs or condemned). A cylinder passing 
requalification by the external visual inspection must be marked in 
conformance with Sec.  180.213. Specification cylinders must be in 
exclusive service as shown in table 2 to this paragraph (g):

[[Page 85435]]



                                            Table 2 to Paragraph (g)
----------------------------------------------------------------------------------------------------------------
               Cylinders conforming to--                                  Used exclusively for--
----------------------------------------------------------------------------------------------------------------
DOT 3A, DOT 3AA, DOT 3A480X, DOT 4AA480................  Anhydrous ammonia of at least 99.95% purity.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA,    Butadiene, inhibited, that is commercially free from
 DOT 4BW.                                                 corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B. DOT 4AA480, DOT     Cyclopropane that is commercially free from corroding
 4B, DOT 4BA, DOT 4BW.                                    components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW,   Chlorinated hydrocarbons and mixtures thereof that are
 DOT 4E.                                                  commercially free from corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B, DOT 4BA, DOT 4BW,   Fluorinated hydrocarbons and mixtures thereof that are
 DOT 4E.                                                  commercially free from corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA,    Liquefied hydrocarbon gas that is commercially free of
 DOT 4BW, DOT 4E.                                         corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B, DOT 4B, DOT 4BA,    Liquefied petroleum gas that meets the detail
 DOT 4BW, DOT 4E.                                         requirements limits in Table 1 of ASTM 1835, Standard
                                                          Specification for Liquefied Petroleum (LP) Gases
                                                          (incorporated by reference; see Sec.   171.7 of this
                                                          subchapter) or an equivalent standard containing the
                                                          same limits.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT   Methylacetylene-propadiene, stabilized, that is
 4E.                                                      commercially free from corroding components.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW, DOT   Propylene that is commercially free from corroding
 4E.                                                      components.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT 4BA, DOT 4BW......  Anhydrous mono, di, trimethylamines that are
                                                          commercially free from corroding components.
DOT 4B240, DOT 4BW240..................................  Ethyleneimine, stabilized.
DOT 4BW................................................  Alkali metal alloys, liquid, n.o.s., Alkali metal
                                                          dispersions or Alkaline earth metal dispersions,
                                                          Potassium, Potassium Sodium alloys and Sodium that are
                                                          commercially free of corroding components.
----------------------------------------------------------------------------------------------------------------

* * * * *
    (j) Cylinder used as a fire extinguisher. Only a DOT-specification 
cylinder used as a fire extinguisher in conformance with Sec.  
173.309(a) of this subchapter may be requalified in conformance with 
this paragraph (j). The testing procedures, calibration of the testing 
equipment, accuracy of the pressure indicating device, accuracy of the 
testing equipment must be as prescribed in CGA C-1.
    (1) A DOT 4B, 4BA, 4B240ET or 4BW cylinder used as a fire 
extinguisher may be tested as follows:
    (i) For a cylinder with a water capacity of 5.44 kg (12 pounds) or 
less, by the water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. A requalification must be performed 
by the end of 12 years after the original test date and at 12-year 
intervals thereafter.
    (A) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (B) When testing using the water-jacket or direct expansion test 
method, the permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
    (C) When testing using the proof pressure test method, the cylinder 
must be carefully examined under test pressure and removed from service 
if a leak or defect is found.
    (ii) For a cylinder having a water capacity over 5.44 kg (12 
pounds), by the water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. For the water-jacket or direct 
expansion test, the requalification must be performed by the end of 12 
years after the original test date and at 12-year intervals theafter. 
For the proof-pressure test, a requalification must be performed by the 
end of 12 years after the original test date and at seven (7) year 
intervals.
    (A) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (B) When testing using the water-jacket or direct expansion test 
method, the permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
    (C) When testing using the proof pressure test method, the cylinder 
must be carefully examined under test pressure and removed from service 
if a leak or defect is found.
    (2) A DOT 3A, 3AA, or 3AL cylinder must be requalified by:
    (i) The water-jacket or direct expansion method. A requalification 
must be performed 12 years after the original test date and at 12-year 
intervals thereafter.
    (ii) Each cylinder must be tested to a minimum of \5/3\ times 
service pressure.
    (iii) When testing using the water-jacket or direct expansion test 
method, the permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *
    (l) * * *
    (1) It has been inspected, tested and marked in conformance with 
the procedures and requirements of this subpart or the Associate 
Administrator has authorized the filling company to fill foreign 
cylinders under an alternative method of qualification; and
* * * * *

0
48. In Sec.  180.212, add paragraph (a)(3) to read as follows:


Sec.  180.212   Repair of seamless DOT 3-series specification cylinders 
and seamless UN pressure receptacles.

    (a) * * *
    (3) If grinding is performed on a DOT 3-series cylinder or a 
seamless UN pressure receptacle, the following conditions apply after 
grinding has been completed. Grinding must not be used to remove arc 
burns from a cylinder, as such a cylinder must be condemned:
    (i) Ultrasonic examination must be conducted to ensure that the 
wall thickness is not less than the minimum design requirement. The 
wall thickness must be measured in at least 3 different areas for every 
10 square inches of grinding area.
    (ii) The cylinder must be requalified in conformance with Sec.  
180.205.
    (iii) The cylinder must be marked in accordance with Sec.  
180.213(f)(10) to indicate compliance with this paragraph (a)(3).
* * * * *


0
49. In Sec.  180.213, revise paragraphs (c) and (d)(2) and add 
paragraphs (f)(10) and (11) and (g) to read as follows:


Sec.  180.213   Requalification markings.

* * * * *
    (c) Requalification marking method. The depth of requalification 
markings may not be greater than specified in the

[[Page 85436]]

applicable specification. The markings must be made by stamping, 
engraving, scribing or applying a label embedded in epoxy that will 
remain legible and durable throughout the life of the cylinder, or by 
other methods that produce a legible, durable mark.
    (1) A cylinder used as a fire extinguisher (see Sec.  180.209(j)) 
may be marked by using a pressure sensitive label.
    (2) For a DOT 3HT cylinder, when stamped, the test date and RIN 
must be applied by low-stress steel stamps to a depth no greater than 
that prescribed at the time of manufacture. Stamping on the sidewall is 
not authorized.
    (3) For a composite cylinder, the requalification markings must be 
applied on a pressure sensitive label, securely affixed and overcoated 
with epoxy in a manner prescribed by the cylinder manufacturer, near 
the original manufacturer's label. Stamping of the composite surface is 
not authorized.
    (d) * * *
    (2) A cylinder subject to the requirements of Sec.  171.23(a)(5) of 
this subchapter must be marked with the date and RIN in accordance with 
this paragraph (d) and paragraph (f)(11) of this section, or marked in 
accordance with the requalification authorized by the Associate 
Administrator in accordance with Sec.  171.23(a)(5)(i) of this 
subchapter.
* * * * *
    (f) * * *
    (10) For designation of grinding with ultrasonic wall thickness 
examination, the marking is as illustrated in paragraph (d) of this 
section, except the ``X'' is replaced with the letter ``R''.
    (11) For designation of requalification of a foreign cylinder 
requalified in conformance with Sec. Sec.  171.23(a)(5) of this 
subchapter and 180.209(l), the marking is as illustrated in paragraph 
(d) of this section, except that the ``X'' is replaced with the letters 
``EX'' to indicate that the cylinder is for export only.
    (g) Visual inspection requalification markings. (1) Alternative to 
the marking requirements of paragraphs (d) and (f)(5) of this section, 
each cylinder successfully passing a visual inspection only, in 
accordance with Sec.  180.209(g), may be marked with the visual 
inspection number (e.g., V123456) issued to a person performing visual 
inspections. Examples of the way the markings may be applied are as 
follows:
[GRAPHIC] [TIFF OMITTED] TR28DE20.498

(2) Where:

(i) ``03'' is the month of requalification (the additional numeral 
``0'' is optional'');
(ii) ``V123456'' is the RIN;
(iii) ``14'' is the year of requalification; and
(iv) ``E'' to indicate visual inspection.


0
50. In Sec.  180.215, revise paragraphs (a)(6), (b), and (c)(2)(vii) 
and add paragraph (c)(3) to read as follows:


Sec.  180.215   Reporting and record retention requirements.

    (a) * * *
    (6) The information contained in each applicable CGA or ASTM 
standard incorporated by reference in Sec.  171.7 of this subchapter 
applicable to the requalifier's activities.
    (b) Requalification records. Daily records of visual inspection, 
pressure test, eddy current examination if required, and ultrasonic 
examination if permitted under a special permit, as applicable, must be 
maintained by the person who performs the requalification until either 
the expiration of the requalification period or until the cylinder is 
again requalified, whichever occurs first. A single date may be used 
for each test sheet, provided each test on the sheet was conducted on 
that date. Ditto marks or a solid vertical line may be used to indicate 
repetition of the preceding entry for the following entries only: Date; 
actual dimensions; manufacturer's name or symbol, if present; owner's 
name or symbol, if present; and test operator. Blank spaces may not be 
used to indicate repetition of a prior entry. A symbol may be used for 
the actual dimensions if there is a reference chart available at the 
facility that lists the actual dimensions of every symbol used. The 
records must include the following information:
    (1) Calibration test records. For each test to demonstrate 
calibration, the date; serial number of the calibrated cylinder; 
calibration test pressure; total, elastic and permanent expansions; and 
legible identification of test operator. The test operator must be able 
to demonstrate that the results of the daily calibration verification 
correspond to the hydrostatic tests performed on that day. The daily 
verification of calibration(s) may be recorded on the same sheets as, 
and with, test records for that date, or may be recorded on a separate 
sheet.
    (2) Pressure test and visual inspection records. The date of 
requalification; serial number; DOT-specification or special permit 
number; marked pressure; actual dimensions; manufacturer's name or 
symbol, if present; year of manufacture; owner's name or symbol, if 
present; gas service; result of visual inspection; actual test 
pressure; total, elastic and permanent expansions; percent permanent 
expansion; disposition, with reason for any repeated test, rejection or 
condemnation; and legible identification of test operator. For each 
cylinder marked pursuant to Sec.  173.302a(b)(5) of this subchapter, 
the test sheet must indicate the method by which any average or maximum 
wall stress was computed. Records must be kept for all completed, as 
well as unsuccessful tests. The entry for a repeated test must indicate 
the date of the earlier test, if conducted on a different day.
    (3) Wall stress. Calculations of average and maximum wall stress 
pursuant to Sec.  173.302a(b)(3) of this subchapter, if performed.
    (4) Calibration certificates. The most recent certificate of 
calibration must be maintained for each calibrated cylinder, pressure 
indicating device, and expansion indicating device.
    (c) * * *

[[Page 85437]]

    (2) * * *
    (vii) Results of a test on a cylinder, including test method, test 
pressure, total expansion, permanent expansion, elastic expansion, 
percent permanent expansion (permanent expansion may not exceed ten 
percent (10 percent) of total expansion), and volumetric capacity 
(volumetric capacity of a rebuilt cylinder must be within <plus-minus>3 
percent of the calculated capacity);
* * * * *
    (3) A record of grinding and ultrasonic examination in conformance 
with Sec.  180.212(a)(3) must be completed for each cylinder on which 
grinding is performed. The record must be clear, legible, and contain 
the following information:
    (i) Name and address of the test facility, date of test report, and 
name or original manufacturer;
    (ii) Marks stamped on cylinder to include specification number, 
service pressure, serial number, symbol of manufacturer, and date of 
manufacture;
    (iii) Cylinder outside diameter and length in inches;
    (iv) Detailed map of where the grinding was performed on the 
cylinder; and
    (v) Wall thickness measurements in grind area in conformance with 
Sec.  180.212(a)(3)(i).

    Issued in Washington, DC, on November 23, 2020, under authority 
delegated in 49 CFR part 1.97.
Drue Pearce,
Deputy Administrator, Pipeline and Hazardous Materials Safety 
Administration.
[FR Doc. 2020-26264 Filed 12-23-20; 8:45 am]
BILLING CODE 4910-60-P


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