Document ID: PHMSA-2011-0140-0031
Agency: phmsa
Document Type: Proposed Rule
Title: Hazardous Materials: DOT-Specification Cylinders (RRR)
Posted Date: 2016-07-26T04:00Z

[Federal Register Volume 81, Number 143 (Tuesday, July 26, 2016)]
[Proposed Rules]
[Pages 48977-49022]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-16689]

[[Page 48977]]

Vol. 81

Tuesday,

No. 143

July 26, 2016

Part III

Department of Transportation

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 Pipeline and Hazardous Materials Safety Administration

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49 CFR Parts 107, 171, 172, et al.

Hazardous Materials: Miscellaneous Amendments Pertaining to DOT-
Specification Cylinders (RRR); Proposed Rule

  Federal Register / Vol. 81 , No. 143 / Tuesday, July 26, 2016 / 
Proposed Rules  

[[Page 48978]]

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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Parts 107, 171, 172, 173, 178 and 180

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

Hazardous Materials: Miscellaneous Amendments Pertaining to DOT-
Specification Cylinders (RRR)

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The Pipeline and Hazardous Materials Safety Administration 
(PHMSA) is proposing to amend the Hazardous Materials Regulations 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 to agency review of the compressed gas cylinders 
regulations. Specifically, PHMSA is proposing to incorporate by 
reference or update the references to several Compressed Gas 
Association publications, amend the filling requirements for compressed 
and liquefied gases, expand the use of salvage cylinders, and revise 
and clarify the manufacture and requalification requirements for 
cylinders.

DATES: Comments must be submitted by September 26, 2016. To the extent 
possible, PHMSA will consider late-filed comments as a final rule is 
developed.

ADDRESSES: You may submit comments identified by the docket number 
PHMSA-2011-0140 (HM-234) by any of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments.
     Fax: 1-202-493-2251.
     Mail: Docket Management System; U.S. Department of 
Transportation, West Building, Ground Floor, Room W12-140, Routing 
Symbol M-30, 1200 New Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: To the Docket Management System; Room W12-
140 on the ground floor of the West Building, 1200 New Jersey Avenue 
SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays.
    Instructions: All submissions must include the agency name and 
docket number for this NPRM at the beginning of the comment. To avoid 
duplication, please use only one of these four methods. All comments 
received will be posted without change to the Federal Docket Management 
System (FDMS), including any personal information.
    Docket: For access to the dockets to read background documents or 
comments received, go to http://www.regulations.gov or DOT's Docket 
Operations Office (see ADDRESSES). To access and review the ASME 
material proposed for incorporation by reference in this rulemaking, 
please refer to the following Web site: http://go.asme.org/PHMSA-ASME-PRM. To access and review the CGA materials proposed for incorporation 
by reference in this rulemaking, please refer to the following Web 
site: https://www.cganet.com/customer/dot.aspx.
    Privacy Act: Anyone is able to search the electronic form of any 
written communications and comments received into any of our dockets by 
the name of the individual submitting the document (or signing the 
document, if submitted on behalf of an association, business, labor 
union, etc.). You may review DOT's complete Privacy Act Statement in 
the Federal Register published on April 11, 2000 (65 FR 19477), or you 
may visit http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Eileen Edmonson, 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. Petitions for Rulemaking and Comments Received
IV. Special Permits
V. Agency Initiated Editorial Corrections
VI. Section-by-Section Review
VII. Regulatory Analyses and Notices
    A. Statutory/Legal Authority for This NPRM
    B. Executive Order 12866, Executive Order 13563, and DOT 
Regulatory Policies and Procedures
    C. Executive Order 13132
    D. Executive Order 13175
    E. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Procedures and Policies
    F. Paperwork Reduction Act
    G. Regulation Identifier Number (RIN)
    H. Unfunded Mandates Reform Act of 1995
    I. Environmental Assessment
    J. Privacy Act
    K. International Trade Analysis

I. Executive Summary

    Cylinders filled with a Class 2 hazardous material (gas) and 
offered for transportation must comply with various subparts 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 continued qualification, maintenance, and periodic 
requalification of cylinders. Additionally, cylinders must meet other 
requirements in the HMR, such as regulations that address the modal 
effects on cylinders in transportation including general handling, 
loading, unloading, and stowage.
    PHMSA (also ``we'' or ``us''), in response to petitions for 
rulemaking submitted by stakeholders and an agency initiated review of 
the regulations, is proposing 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; revising and clarifying the 
manufacture and requalification requirements for cylinders; and 
adopting a special permit (DOT-SP 14237). This NPRM is also presenting 
minor and miscellaneous regulatory editorial corrections. Further, 
PHMSA is addressing the comments received from a previous Advance 
Notice of Proposed Rulemaking (ANPRM; 77 FR 31551), and proposing 
additional revisions that have been requested in petitions received 
since the ANPRM's 2012 publication. These proposed revisions intend to 
reduce regulatory burdens while maintaining or enhancing the existing 
level of safety. In this NPRM, PHMSA is responding to 20 petitions for 
rulemaking submitted by stakeholders.

II. ANPRM Background

    On May 29, 2012 [77 FR 31551], PHMSA published an ANPRM to obtain 
public comment from those likely to be affected by the possible 
incorporation of 10 petitions for rulemaking and 3 special permits into 
the HMR. These include cylinder manufacturers (approximately 568 
companies); cylinder requalifiers; independent

[[Page 48979]]

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. Incorporating these 
petitions for rulemaking and special permits would 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 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 supporting for all but 
one--P-1515. PHMSA received four comments regarding 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:

      Table 1--ANPRM Commenters and Associated Comments Docket Nos.
------------------------------------------------------------------------
             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.......  PHMSA-2011-0140-0005
                                   PHMSA-2011-0140-0012
                                   PHMSA-2011-0140-0013
                                   PHMSA-2011-0140-0020
Council on Safe Transportation of  PHMSA-2011-0140-0026
 Hazardous Articles, Inc.
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
------------------------------------------------------------------------

III. Petitions for Rulemaking and Comments Received

    Table 2 lists the petitions included in the docket for this 
proceeding. This NPRM addresses 20 total petitions. Ten petitions are 
associated with the ANPRM, and 10 additional petitions have been 
included since its publication. This table provides the petition 
number, the petitioner's name, the docket number on 
www.regulations.gov, a brief summary of the petitioner's requests, the 
affected sections, and whether or not we are proposing to adopt the 
petition:

                                            Table 2--Petition Summary
----------------------------------------------------------------------------------------------------------------
                                                                                    Proposed
   Petition No.       Petitioner            Docket No.             Summary          affected       Proposing to
                                                                                    sections          adopt?
----------------------------------------------------------------------------------------------------------------
P-1499...........  Compressed Gas    PHMSA-2007-28485........  Replace the      Sec.  Sec.       Yes.
                    Association.                                incorporated     171.7; 172.102
                                                                by reference     (SP 338);
                                                                (IBR) Seventh    173.3(d)(9);
                                                                Edition of the   173.198(a);
                                                                CGA C-6          180.205(f)(1);
                                                                Standards for    180.209(c),
                                                                Visual           (b)(1)(iii),
                                                                Inspection of    (d), (f), (g),
                                                                Steel            (m);
                                                                Compressed Gas   180.211(d)(1)(
                                                                Cylinders with   ii);
                                                                the revised      180.411(b);
                                                                Tenth Edition    180.510(c).
                                                                and update the
                                                                appropriate
                                                                references
                                                                throughout the
                                                                HMR.
P-1501...........  Compressed Gas    PHMSA-2007-28759........  Revise the       Sec.  Sec.       Yes, in part.
                    Association.                                specification    178.50,
                                                                requirements     178.51,
                                                                for 4B, 4BA,     178.61, 178.68.
                                                                4BW, and 4E
                                                                cylinders to
                                                                provide
                                                                clarity.
P-1515...........  Certified         PHMSA-2008-0101.........  Adopt changes    Sec.  Sec.       Yes, except
                    Training                                    to the           180.203,         those changes
                    Company.                                    requalificatio   180.205,         not necessary
                                                                n process        180.207,         because of IBR
                                                                designed to      180.209,         of CGA C-1
                                                                clarify the      180.211,         under P-1626.
                                                                regulations in   180.212,
                                                                the event CGA    180.213,
                                                                Standard C-1,    180.215,
                                                                Methods of       appendix C to
                                                                Pressure         part 180,
                                                                Testing          appendix E to
                                                                Compressed Gas   part 180.
                                                                Cylinders, is
                                                                not
                                                                incorporated.

[[Page 48980]]

 
P-1521...........  Compressed Gas    PHMSA-2008-0152.........  Allow the use    Sec.             Yes.
                    Association.                                of labels        172.400a(a)(1)
                                                                described in     (i).
                                                                CGA C-7-2004
                                                                on a cylinder
                                                                contained in
                                                                an overpack.
P-1538...........  The Wicks Group,  PHMSA-2009-0138.........  Allow Sec.       Sec.  Sec.       No.
                    representing                                173.306(a)(1)    171.8,
                    Jetboil Inc.                                to permit        173.306(a)(1).
                                                                camping stove
                                                                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,    Sec.             No.
                                                                3AA, 3AL         180.209(a).
                                                                cylinders in
                                                                Division 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.             Yes.
                    Association.                                manufactured     178.35(f).
                                                                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  Sec.             Yes.
                    Services, Inc.                              used as a        173.309(a).
                                                                component of a
                                                                fixed fire
                                                                suppression
                                                                system to be
                                                                transported
                                                                under the
                                                                exceptions
                                                                applicable to
                                                                fire
                                                                extinguishers.
P-1560...........  Air Products and  PHMSA-2010-0176.........  Modify the       Sec.             No. Addressed
                    Chemicals, Inc.                             maximum          173.304a(a)(2).  by revisions
                                                                permitted                         made under
                                                                filling                           rulemaking HM-
                                                                densities for                     233F [81 FR
                                                                carbon dioxide                    3635].
                                                                and nitrous
                                                                oxide to
                                                                include 70.3%,
                                                                73.2%, and
                                                                74.5% in DOT
                                                                3A, 3AA, 3AX,
                                                                3AAX, and 3T
                                                                cylinders.
P-1563...........  Regulatory        PHMSA-2010-0208.........  Authorize an     Sec.   173.301   Uncertain. We
                    Affairs                                     ``overpack''     (a)(9).          are asking for
                    Management                                  as a strong                       further
                    Center--3M                                  outer package                     comment.
                    Package                                     for cylinders
                    Engineering,                                listed in the
                    Global                                      section,
                    Dangerous Goods.                            except
                                                                aerosols
                                                                ``2P'' and
                                                                ``2Q,'' marked
                                                                with the
                                                                phrase ``inner
                                                                packagings
                                                                conform to the
                                                                prescribed
                                                                specifications
                                                                ''.
P-1572...........  Barlen and        PHMSA-2011-0017.........  Revise the       Sec.  Sec.       Yes, in part.
                    Associates,                                 filling ratio    173.301(g)(1)(
                    Inc.                                        for liquefied    ii) and
                                                                compressed       173.312.
                                                                gases in 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      Sec.  Sec.       Yes.
                                                                burst pressure   173.301(f)(4),
                                                                of the rupture   173.302(f)(2),
                                                                disc on a        173.304(f)(2).
                                                                cylinder
                                                                ``shall not
                                                                exceed 80% of
                                                                the minimum
                                                                cylinder burst
                                                                pressure and
                                                                shall not be
                                                                less than 105%
                                                                of the
                                                                cylinder test
                                                                pressure''.
P-1582...........  Water Systems     PHMSA-2011-0135.........  Revise the       Sec.             Yes.
                    Council.                                    limited          173.306(g).
                                                                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
                                                                ).

[[Page 48981]]

 
P-1592...........  Compressed Gas    PHMSA-2012-0173.........  IBR CGA S-1.1,   Sec.  Sec.       Yes.
                    Association.                                2011 Pressure    173.301(c),
                                                                Relief Device    (f) and (g),
                                                                Standards,       173.304a(e),
                                                                Part 1,          178.75(f).
                                                                Cylinder for
                                                                Compressed
                                                                Gas,
                                                                Fourteenth
                                                                Edition.
P-1596...........  Chemically        PHMSA-2012-0200.........  Add Class 4 and  Sec.             Yes.
                    Speaking, LLC.                              Class 5          173.3(d)(2).
                                                                hazardous
                                                                materials to
                                                                the hazard
                                                                classes in an
                                                                authorized
                                                                salvage
                                                                cylinders.
P-1622...........  Worthington       PHMSA-2013-0210.........  Restrict the     Sec.  Sec.       Yes.
                    Cylinders                                   internal         173.304a and
                    Corporation.                                volume of        173.304a(a)(3).
                                                                hazardous
                                                                materials
                                                                shipped in a
                                                                DOT-
                                                                specification
                                                                39 cylinder to
                                                                not exceed 75
                                                                cubic inches.
P-1626...........  Compressed Gas    PHMSA-2013-0265.........  IBR CGA C-1-     Sec.  Sec.       Yes.
                    Association.                                2009, Methods    171.7, 178.36,
                                                                for Pressure     178.37,
                                                                Testing          178.38,
                                                                Compressed Gas   178.39,
                                                                Cylinders,       178.42,
                                                                Tenth Edition    178.44,
                                                                (C-1, 2009) as   178.45,
                                                                a reference in   178.46,
                                                                49 CFR, and      178.47,
                                                                provide for      178.50,
                                                                specific         178.51,
                                                                language for     178.53,
                                                                sections         178.55,
                                                                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-     Sec.  Sec.       Yes.
                    Association.                                2005,            171.7, 178.47,
                                                                Reaffirmed       178.50,
                                                                2011,            178.51,
                                                                Standards for    178.53,
                                                                Welding on       178.55,
                                                                Thin-Walled,     178.56,
                                                                Steel            178.57,
                                                                Cylinders,       178.58,
                                                                Seventh          178.59,
                                                                Edition.         178.60,
                                                                                 178.61,
                                                                                 178.65,
                                                                                 178.68,
                                                                                 180.211.
P-1629...........  Compressed Gas    PHMSA-2014-0012.........  IBR CGA C-14-    Sec.  Sec.       Yes.
                    Association.                                2005,            171.7,
                                                                Reaffirmed       173.301,
                                                                2010,            173.323.
                                                                Procedures for
                                                                Fire 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.       Yes.
                    Association.                                ``recondition'   180.203,
                                                                ' for DOT-4L     180.211(c),
                                                                welded           and 180.211(e).
                                                                insulated
                                                                cylinders 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 CGA submitted P-1499 requesting that PHMSA replace the 
currently incorporated by reference C-6 Standards for Visual Inspection 
of Steel Compressed Gas Cylinders, Seventh Edition with the revised 
Tenth Edition and update the appropriate references throughout the HMR. 
The Tenth Edition provides enhanced guidance for cylinder 
requalifiers--including guidance on the inspection of Multiple-Element 
Gas Containers (MEGCs) and the requirements for thread inspection for 
cylinders used in corrosive gas service--and clarifies maximum 
allowable depths and measuring techniques for various types of 
corrosion.
    PHMSA identified approximately 5,000 companies that would be 
subject to this standard, with the majority being classified as small 
businesses using the Small Business Administration (SBA) size standards 
(<500 employees). This revision would impose a one-time cost of between 
$78 and $142 per document depending on the document format (electronic 
or hard copy) and the purchaser's CGA membership.
    Air Products and Chemicals, City Carbonic, CGA, Hydro-Test 
Products, and Worthington Cylinders support the proposal as discussed 
in the May 29, 2012 ANPRM. No commenters objected to the proposal.
    PHMSA agrees that the Tenth Edition provides improved and updated 
guidance on inspecting MEGCs. While there were no comments opposed to 
the incorporation, subsequent to the submission of this petition, a 
more current updated version of CGA C-6 has been made available (i.e., 
an eleventh edition). Therefore, in this NPRM, PHMSA is proposing to 
update the IBR of CGA C-6 to the 2013 Eleventh Edition. We invite 
comment on this course of action.

P-1501

    The CGA submitted P-1501 requesting that PHMSA revise the 
manufacturing requirements for DOT 4B, 4BA, 4BW, and 4E cylinders. 
According to the petition, the current DOT-4 series welded cylinder 
manufacturing requirements are unclear in some respects and result in 
varied interpretation by manufacturers and enforcement personnel. The 
CGA states that although the proposed changes do not present a 
significant economic impact to any single manufacturer or user, they 
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, which is referenced in the UN Model 
Regulations.

[[Page 48982]]

    Summary of the changes proposed by P-1501 and the comments received 
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.
    Norris Cylinder sought clarification on the requirement to report 
intentionally added alloying elements. Specifically, Norris Cylinder 
inquired if PHMSA would require the manufacturer to maintain documents 
other than the mill certificate and the DOT Test Report.
    PHMSA has decided that the proposed revisions to Sec. Sec.  
178.50(b), 178.51(b), 178.61(b), and 178.68(b) with respect to proposed 
measure (2) above is not necessary based on the required duties of 
inspectors in Sec.  178.35(c)(2) to verify 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 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. As pointed out by Norris cylinder, the 
regulatory text proposed by CGA does not specify who must maintain the 
document. In this NPRM, we specify that the cylinder manufacturer must 
maintain the record of intentionally added alloying elements. Further, 
we are not proposing to require a check analysis to confirm the ladle 
analysis for materials manufactured outside of the United States 
because we believe this is already addressed by requiring domestic 
performance of required check analyses under Sec.  178.35(b) of the 
HMR. We invite comment on this course of action.
    (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.
    Hydro-Test Products and Manchester Tank expressed concern that 
PHMSA would allow a pneumatic pressure test. Because the potential 
release of energy in the event of a cylinder rupture during a pneumatic 
test is much greater than that released if a cylinder ruptured during a 
hydrostatic test, the commenters state that the person conducting the 
test must take additional precautions to safeguard against injury, such 
as erecting a safety barrier to protect personnel. Worthington 
Cylinders noted that it had extensive experience conducting proof 
pressure tests with gas but further stated that each company's safety 
considerations of the testing equipment will be different.
    Given the added risk associated with pneumatic testing and the fact 
that there are suitable alternatives to determine the leakproofness of 
a cylinder at the time of manufacture, PHMSA is not proposing to permit 
the use of pneumatic proof pressure testing in this NPRM.
    (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.
    Manchester Tank requested that the specific proposed wording, or 
more detailed information, be made available for comment. Readers may 
review the specific changes to these sections at the end of this 
document.
    (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.
    Manchester Tank and Worthington Cylinders support the CGA proposal 
that would allow markings to be applied to the footring on cylinders up 
to 30-pounds water capacity, instead of the current capacity limit of 
25 pounds. The commenters state that this revision would not impose any 
cost and would expand upon existing options. In this NPRM, PHMSA is 
proposing this revision as stated in the petition.
    (5) Add requirements for the location of markings on DOT 4E 
cylinders in Sec.  178.68.
    Manchester Tank and Worthington Cylinders support the proposed 
modification to permit marking of the valve protection collar of DOT 4E 
cylinders. In this NPRM, PHMSA is proposing the revision as stated in 
the petition.

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. These requirements include 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. 
The CTC states that the current requirements create confusion for 
requalifiers and enforcement officials. In the ANPRM, PHMSA requested 
comments on two possible methods of responding to this petition. The 
first, as was suggested by CTC in P-1515, was to modify the specific 
HMR provisions in Sec. Sec.  180.203 through 180.215 for 
requalification of cylinders. The second was to IBR into Sec.  180.205 
CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders, Tenth 
Edition (2009), which contains most of the provisions and additions 
specified in P-1515, including revisions to definitions in Sec.  
180.203, appropriate procedures for conducting the hydraulic pressure 
tests, and marking and recordkeeping requirements.
    PHMSA identified 980 entities that conduct hydrostatic retesting. 
Incorporation of CGA C-1 would impose a one-time cost of between $102 
and $186 per document depending on the document format (electronic or 
hard copy) and the purchaser's CGA membership.
    We received eight comments on this petition. Air Products and 
Chemicals, CGA, Bancroft Hinchley, and Worthington Cylinders support 
adoption of the CGA C-1 standard. Conversely, Hydro-Test Products 
stated that the proposals in P-1515 and the CGA C-1 impose stricter 
requirements on accuracy, pressure drop, and verification, therefore 
imposing an unnecessary burden on the industry. SodaStream requested 
PHMSA modify the appropriate sections of 49 CFR part 180, subpart C, 
instead, as adoption of CGA C-1 would limit their ability to conduct 
volumetric expansion tests and would result in a need to obtain a 
special permit.
    As indicated by Worthington Cylinders, several commenters stated 
similar concerns to those shared regarding the option to IBR CGA C-1, 
with Worthington Cylinders further stating that CGA C-1 ``represents 
the best testing practices for the industry.'' Moreover, as indicated 
by CGA, the

[[Page 48983]]

changes proposed in P-1515 would not resolve the confusion of 
requalifiers and enforcement officials that the petition seeks to 
address. For these reasons, in this NPRM, PHMSA is proposing to IBR CGA 
C-1, Methods for Pressure Testing Compressed Gas Cylinders, at Sec.  
171.7 and into Sec.  180.205 and numerous other sections (see 
discussion of Petition P-1626). However, subsequent to the submission 
of this petition, an eleventh edition of CGA C-1 has been made 
available. Therefore, in this NPRM, PHMSA is proposing to update the 
IBR of CGA C-1 to the 2016 Eleventh Edition. We invite comment on this 
course of action.
    The CTC further requests that PHMSA correct and reissue two letters 
of interpretation (Reference Nos. 00-0309 and 05-0087), as well as 
provide formal interpretation on six additional issues identified in 
its petition. PHMSA invites public comment on the questions, 
recommendations, and proposed responses detailed below:
(1) Existing Clarification Letter Reference No. 00-0309
    On March 15, 2001, PHMSA responded to an inquiry from Vallen 
Technical Services (VTS) pertaining to the pressure retest of DOT-
specification cylinders (Reference No. 00-0309). Citing that former 
Sec.  173.34(e)(4)(v)--currently Sec.  180.205(g)(5)--states, ``In the 
case of a malfunction of the test equipment, the test may be repeated 
at a pressure increased by 10 percent or 100 [pounds per square inch] 
psi, whichever is less,'' VTS stated its understanding that only one 
repeat test is permitted. PHMSA responded with the following: ``Your 
understanding of this requirement is correct. Section 173.34(e)(4)(v) 
permits only one repeat test in the case of a malfunction of the test 
equipment. With regards to your reference to the Compressed Gas 
Association (CGA) pamphlet C-1, currently the HMR do not incorporate 
the pamphlet by reference. However, we proposed in a notice of proposed 
rulemaking to reference certain pressure test procedures contained in 
the CGA pamphlet. (Docket No. HM-98-3684 (HM-220); October 30, 1998).''
    The CTC states that Sec.  180.205(g)(5) ``permits only one repeated 
test'' and further posits that this letter's response directly 
contradicts language PHMSA previously issued in a final rule [Docket 
No. HM-220A (61 FR 26750); February 28, 1996)] that states: ``A 
commenter specifically asks how many repeated tests are allowed before 
condemning the cylinder, and the response is that the cylinder is to be 
condemned when it exceeds its permanent expansion limit. It even 
specifies, `. . . Thus when this limit [Perm. Expan.] is exceeded . . 
.' [i.e., no limit to the number of repeats is given, even when the 
specific question was asked.]''
    Although the CTC states it favors limiting the number of repeat 
tests of this type, it believes PHMSA's statement on this matter in 
Reference No. 00-0309 ``constitutes a rulechange, not an 
interpretation.'' The CTC believes requiring only one repeat test ``may 
be overly restrictive in some cases, such as small aircraft cylinders, 
and certain composite cylinders,'' and suggests allowing two repeated 
tests, as permitted in special permits DOT-SPs 10915, 10945, and 11194, 
would be ``more in line with current industry procedure.''
    On August 8, 2002, PHMSA's predecessor agency, the Research and 
Special Programs Administration, issued a final rule under Docket No. 
HM-220D that consolidated the requirements for qualification, use, and 
maintenance of cylinders in 49 CFR part 180, subpart C. As a result, 
the regulatory sections referred to in Reference No. 00-0309 are no 
longer correct. Further, not all the requirements previously codified 
in Sec.  173.34 have parallel requirements in 49 CFR [art 180, subpart 
C. See Sec.  180.205(g)(5) for additional information. However, PHMSA 
agrees with the CTC that the language in Reference No. 00-0309 may be 
misleading and believes the IBR of CGA C-1 into Sec.  180.205 will 
resolve any issue the CTC may have with this letter of interpretation. 
We invite comment on this conclusion. PHMSA also plans to retract 
Reference No. 00-0309.

(2) Existing Clarification Letter Reference No. 05-0087

    On May 10, 2005, PHMSA responded to an inquiry from G&C Kinney, 
Inc., concerning calibration verification of equipment used for 
volumetric expansion tests for DOT-specification cylinders (Reference 
No. 05-0087). The company asked whether the maximum pressure at which 
the verification test is being conducted (for example, 3,000 pounds) 
must be maintained at the final pressure for 30 seconds or whether the 
pressure may be allowed to drop between 2 psi and 10 psi. PHMSA 
responded by stating, ``Overall, for any pressure test (calibration or 
production retest), the 30-second hold time begins only when the 
cylinder has completed its expansion. If the cylinder pressure drops by 
any measurable amount (such as 2 psi) during the recorded 30-second 
hold time, the hold time must be restarted, or the test would be 
considered invalid.''
    The CTC requests that PHMSA retract its Reference No. 05-0087 
response because it contradicts regulatory text found in Sec.  
180.205(g)(2), (g)(3)(i), and (g)(5); DOT-SPs 10915 and 10945; 
standards in CGA C-1, Seventh Edition (1996); and some manuals of 
manufacturers of hydrostatic test equipment. Specifically, the CTC 
states the following:

    Paragraph 180.205(g)(5) states, ``Minimum test pressure must be 
maintained for at least 30 seconds, and as long as necessary for 
complete expansion of the cylinder.'' [Emphasis added.] This 
statement tells us that the cylinder may be expanding during the 30 
second hold time, and if the cylinder is still expanding at the end 
of the 30 seconds, we must hold even longer than the minimum 30 
seconds. As the cylinder expands, its volume increases, and pressure 
will drop. Therefore, the statement ``as long as necessary for 
complete expansion of the cylinder'' is equivalent to saying ``until 
the pressure ceases to drop''. The regulations state that this may 
occur during the 30 second hold time; the regulations do not specify 
the hold time begins after the cylinder has completed its expansion. 
Therefore, this ``interpretation'' directly contradicts Sec.  
180.205(g)(5), and constitutes a rule change.
    Paragraph 180.205(g)(2) states, ``[t]he pressure indicating 
device of the testing apparatus must permit reading of pressures to 
within 1% of the minimum prescribed test pressure of each cylinder 
tested.'' Paragraph 180.205(g)(3)(i) states, ``[t]he pressure-
indicating device, as part of the retest apparatus, is accurate 
within 1.0% of the prescribed test pressure of any 
cylinder tested that day.'' This interpretation attempts to declare 
a test invalid due to a 2 psi drop in pressure at 3000 psi. The 
pressure indicating device has already been defined as having a 1% 
resolution and 1% accuracy. According to the definition 
of the device, it can deviate by 30 psi at 3000 psi (30 
psi = 1% of 3000 psi). This interpretation violates the definition 
of the device as stated in these two paragraphs.
    Furthermore, many special permits, such as DOT-SP 10915 and 
10945, recognize that different materials (such as the carbon-fiber 
wrapped, aluminum lined cylinders referenced in these special 
permits) take even longer than 30 seconds to completely deform under 
the load of test pressure, and therefore require a hold time of 60 
seconds. According to this interpretation, these special permits 
would require a hold time of 60 seconds (or longer), until the 
cylinder completed its expansion, and then an additional 60 seconds 
of hold time, wherein the pressure could not drop by even 2 psi. 
This, obviously, is not the intention of these special permits when 
they state, ``. . . for a minimum test time of one minute.''
    Industry standard CGA C-1, Seventh Edition 1996, ``Methods for 
Hydrostatic Testing of Compressed Gas Cylinders,'' in paragraph 
4.4(g) states, ``[w]hen the desired

[[Page 48984]]

value is reached, stop the pressurization and hold for 30 seconds.'' 
And, ``[t]he expansion and pressure should remain stable during the 
entire 30 seconds. If either the pressure or expansion do not 
stabilize within 1%, see 4.5 [Troubleshooting].'' Thus, 
the 30-second hold begins when the pump stops, and deviation during 
the hold time is allowed up to the defined accuracy of the device, 
that is, 1% of the test pressure, and 1% of 
the total expansion.
    Manufacturers of hydrostatic test equipment specify in their 
manuals and the software controlling automated equipment that the 
30-second hold time begins when the test pressure is reached and the 
pump is turned off.

    The CTC further states: ``This interpretation declares virtually 
every test performed on cylinders in the past century to be invalid, 
since every cylinder tested (as well as the hoses on the machine) will 
continue to expand after the pump is stopped. Therefore the pressure 
will drop. The only issue is whether or not the device is capable of 
detecting such a minute drop in pressure.'' The CTC believes this 
interpretation is based on two misunderstandings:
    1. Closed loop hydraulics vs. open system. In a closed loop 
hydraulic system (such as the controls on an aircraft), any drop in 
pressure is unacceptable. This does not apply to an open system where 
the pressure will drop (e.g., a cylinder expanding during a test).
    2. Higher precision digital devices vs. analog devices. There has 
always been a slight drop in pressure during the hold time. On an 
analog device, it was not visible. It is now visible on a digital 
device, but that does not simply invalidate the test.
    PHMSA agrees with the CTC that the language in Reference No. 05-
0087 is misleading and believes the IBR of CGA C-1 into Sec.  180.205, 
in conjunction with additional changes to the regulations proposed 
consistent with petition P-1626, will resolve any issue the CTC may 
have with this letter of interpretation. We invite comment on this 
conclusion. PHMSA also plans to retract Reference No. 05-0087.

P-1521

    The CGA submitted P-1521 requesting that PHMSA modify the provision 
in Sec.  172.400a(a)(1)(i) 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.
    The HMR permit the use of a neckring marking, under certain 
conditions, in conformance with the CGA C-7, Guide to Preparation of 
Precautionary Labeling and Marking of Compressed Gas Containers, 
Appendix A, Eighth Edition (2004) under Sec.  172.400a. This neckring 
marking identifies the contents of a cylinder by displaying the proper 
shipping name, the UN identification number, and the hazard class or 
division label within a single marking. Section 172.400a(a)(1) permits 
the use of this marking in lieu of required labels on a Dewar flask 
meeting the requirements in Sec.  173.320 or a cylinder containing 
Division 2.1, 2.2, and 2.3 material that is not overpacked. This 
requirement should provide flexibility in hazard communication for 
cylinders, especially small cylinders.
    The marking prescribed in appendix A to CGA C-7 provides useful 
information in a clear and consistent manner, and its widespread use on 
cylinders has enhanced its recognition. CGA's proposed change would 
provide greater flexibility for shipments of overpacked cylinders while 
ensuring adequate hazard communication. If cylinders are contained in 
an overpack, the overpack must display the appropriate markings and 
labels.
    PHMSA identified approximately 86 entities engaged in Industrial 
Gas Manufacturing, of which 74 are classed as small entities (<500 
employees). Other potentially impacted entities include wholesalers of 
medical equipment, service establishment equipment and supplies, and 
other miscellaneous durable goods. In the ANPRM, PHMSA asked for 
comments on the potential implications of this change, specifically 
regarding its necessity and the potential safety and economic impacts. 
PHMSA also sought data concerning the breadth of shipments to be 
impacted by the proposal. PHMSA received no responses to these 
questions from commenters to the ANPRM.
    Both Air Products and Chemicals and Worthington Cylinders support 
CGA's petition to revise Sec.  172.400a(a)(1)(i). Therefore, in this 
NPRM, PHMSA is proposing 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. The 
petition would still require the overpack to display the required 
labels in conformance with 49 CFR part 172, subpart E.

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). Section 173.306 prescribes 
requirements for transporting compressed gases as a limited quantity 
and a consumer commodity. Paragraph (a)(1) of Sec.  173.306 requires a 
container of only compressed gas to be limited to a capacity of 4 fluid 
ounces or less except cigarette lighters, which are required to meet 
rigorous performance design standards and packaging requirements 
prescribed in Sec.  173.308. The Wicks Group states if more than 4 
fluid ounces of the liquefied portion of the gas were enclosed in the 
cylinder, ``there would be insufficient space remaining for the gaseous 
portion of the liquefied gas, as required by [Sec. Sec.  173.304(b) and 
173.304a(d)(1)]. In other words, [Sec. Sec.  173.304(b) and 
173.304a(d)(1)] together limit the percentage of space [emphasis added] 
that the liquefied portion of a liquefied gas may take up in a 
cylinder. Thus, since the canisters at issue here could not safely or 
legally hold more than four (4) fluid ounces of LPG while complying 
with the HMR filling limits and filling density requirements, they can 
reasonably be said to have a capacity of four (4) fluid ounces.'' The 
petitioner included a certificate from the manufacturer of the 
``Jetpower'' 100G canister of cooking fuel, Taeyang Ind., Co., LTD, of 
Seoul, Korea, certifying ``that the capacity of the 100G canister is 
less than 4 oz. because the capacity of the canister should be measured 
by the amount of liquefied gas contents in a fluid condition that it 
can hold, still leaving room for the portion in a gas condition. The 
100G canisters must have less than 4 oz. of liquefied gas to meet that 
requirement. The capacity of the 100G canisters `Jetpower' should be 
considered less than 4 ounces. These canisters are safe for 
transportation as ORM-D.\1\ We are unaware of any problems occurring 
with these canisters in transportation.'' PHMSA seeks public comment on 
the safety issues associated with this proposal, especially those 
regarding the safe performance of containers of this type in 
transportation.
---------------------------------------------------------------------------

    \1\ Note that the ORM-D class will be completely phased out for 
all modes of transportation by December 31, 2020.
---------------------------------------------------------------------------

    The Wicks Group further states on behalf of Jetboil, Inc., that ``. 
. . 49 CFR 173.306(a)(1) is ambiguous as currently drafted. In brief, 
the HMR do not define the term capacity, but do define the term 
`maximum capacity,' at 49 CFR 171.8, as meaning `the maximum inner 
volume of receptacles or packagings.' If PHMSA interprets `capacity' as 
meaning the total volume of the container, then

[[Page 48985]]

the word `maximum' would be rendered meaningless. This violates the 
long-established rule of statutory and regulatory interpretation that 
courts must give effect to every clause and word of a legal text 
whenever possible. Indeed, the omission of a word in one section of a 
text can be telling where that word issued in another section of the 
same act or regulation.'' In addition, the petitioner states providing 
industry an opportunity to comment on this issue in a rulemaking will 
give them the chance ``to explain why these containers present a 
reduced safety risk, and to demonstrate that there have been no 
transportation safety incidents involving these containers.''
    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 petitioner requested 
that PHMSA define the word ``capacity'' in the HMR to add meaning to 
the maximum capacity definition in Sec.  171.8. 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, we are not proposing 
to amend Sec.  173.306(a)(1) to accommodate this petition for 
rulemaking.

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 requests 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 requests 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% 
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 
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.
    Upon further consideration of this petition based on our concern of 
increasing the risk of cylinder failure by lengthening the timeframe 
between periodic qualifications, PHMSA is electing not to 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 invite comment on 
this decision and request detailed information in support or opposition 
to this decision.

P-1540

    The CGA submitted P-1540 requesting that PHMSA require newly 
manufactured DOT 4B, 4BA, 4BW, and 4E cylinders to be marked with the 
mass weight, tare weight, and 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 (i.e., the weight of the 
empty cylinder and appurtenances) or the mass weight (i.e., the weight 
of the empty cylinder), and the water capacity must be known by the 
filler to properly fill the cylinder. 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 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 IBRs the National Fire Protection Association's 
58-Liquefied Petroleum Gas Code (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 IBR of NFPA 58 is not 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

[[Page 48986]]

the ANPRM that these are not the only cylinder types used for liquefied 
compressed gas transport. For that reason, in the ANPRM, PHMSA asked 
for comment regarding the potential revision of 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 or water capacity. 
PHMSA understands that many in the compressed gas industry, especially 
the liquefied petroleum gas industry, already request manufacturers 
mark cylinders with this additional information 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 voluntarily applying these markings. In the ANPRM, 
we requested comment on this assertion.
    PHMSA identified six U.S. based manufacturers of the cylinders 
identified in the petition, of which five are classified as small 
businesses using SBA size standards (< 500 employees). 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:
     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)?
     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?
     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 supports the petition with no additional 
comments. The CGA supports 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 does 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 believes that 
the 49 CFR must further clarify that no cylinder must be filled with a 
liquefied gas unless a mass or tare weight is marked on the cylinder, 
providing the following justification:
     At the time of manufacture, the manufacturer would not 
know whether the DOT 3 series cylinders are or are not be used in a 
liquefied gas service;
     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 
be marked for tare weight and water capacity just because the cylinder 
could be used (at some time) for liquefiable gas;
     There would be instances on small 3-series cylinders where 
the additional marking would not fit onto the dome of the cylinder; and
     The economic impact estimated for marking all cylinders is 
significantly greater than the estimates submitted by PHMSA.
    Manchester Tank expresses concern that numerous variations in 
stamped weights could cause confusion in the field among fillers. They 
state 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 ask PHMSA for specific clarification of the language to 
assign the duty to mark tare weight to the valve installer and indicate 
that there are many cylinders that are not valved by the manufacturer, 
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 this NPRM, PHMSA is proposing to revise Sec.  178.35(f) to 
require that tare weight or mass weight, and water capacity be marked 
on certain DOT 4-series specification cylinders used for the transport 
of liquefied gases as petitioned by the CGA. 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. 
PHMSA seeks additional comment on expanding this marking requirement to 
other DOT-specification cylinders and the costs and benefits as well as 
the safety implications of doing so.

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.\3\ 
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).
---------------------------------------------------------------------------

    \3\ 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 clarification regarding the 
applicability of Sec.  173.309 to fire extinguishers. Notably on March 
9, 2005, PHMSA wrote a letter (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 
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 (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 since 
these cylinders were not equipped to function as fire extinguishers. 
This latter clarification effectively required

[[Page 48987]]

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 suggests 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 this NPRM, PHMSA is proposing to revise the Sec.  173.309 
introductory text to include cylinders used as part of a fire 
suppression system as a cylinder type authorized for transport in 
accordance with the HMT entry for fire extinguishers. The controls 
detailed in Sec.  173.309 provide an acceptable level of safety 
regardless of whether the cylinder is equipped for use as a handheld 
fire extinguisher or as a component of a fixed fire suppression system.

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 accordance with Sec.  173.301(a)(9), DOT-specification 2P, 2Q, 
3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed 
in strong non-bulk outer packagings. This configuration meets the 
definition of a combination package as indicated in paragraph (a)(9) 
and further, as defined in Sec.  171.8 of the HMR. Paragraph (a)(9) 
requires the outside of this combination packaging to be marked with an 
indication that the inner packagings conform to the prescribed 
specifications. The completed combination package is subject to marking 
and labeling, as appropriate; however, the inner packagings do not have 
to be marked or labeled. These combination packages cannot also then be 
considered ``overpacks.'' For each completed package bearing required 
marking(s) and label(s) that is placed in an overpack, for 
consolidation or ease of handling, the overpack must also display the 
appropriate marking(s) and label(s) unless visible through the overpack 
[see Sec.  173.25(a)(2)]. The ``OVERPACK'' mark must be applied when 
specification packagings are required by the HMR to communicate that 
the overpack contains specification packagings in conformance with the 
HMR.
    The marking ``inside (inner) packages comply with the prescribed 
specifications'' for overpacks in Sec.  173.25 was changed in 2004 to 
``OVERPACK'' in an effort to better align with global overpack 
requirements. The 3M Corporation accurately states that prior to 2004 
both the overpack requirements in Sec.  173.25 and the requirement in 
Sec.  173.301(a)(9) to package certain DOT-specification cylinders in 
strong, non-bulk outer packagings used very similar language intended 
to inform package handlers that although not visible, the inner 
packages contained specification packagings that conformed to 
appropriate DOT or UN standards.
    PHMSA recognizes 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 is proposing 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 agree 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, are not 
including 2P and 2Q in the allowance for the ``OVERPACK'' marking. The 
revision will also include instructional language that the combination 
package is not to be considered an ``overpack.'' PHMSA welcomes 
comments from affected entities regarding the following: potential 
consequences, safety and economic impacts, current level of difficulty 
and unnecessary confusion, need for change, quantity of shipments per 
year to be impacted, etc.

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).\4\
---------------------------------------------------------------------------

    \4\ Note that the petition specifically referenced the 17th ed. 
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 
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 this 
NPRM, we propose to specify the filling ratio requirements for pressure 
receptacles.
    PHMSA does not anticipate this provision will impose any new 
burden, as this proposal would only emphasize an important safety 
requirement already stated in Sec.  173.304a for DOT-specification 
cylinders and Sec.  173.304b for UN pressure receptacles. PHMSA invites 
comments from affected entities regarding the following: Safety and 
economic impacts, level of difficulty and unnecessary confusion, need 
for change, etc.

[[Page 48988]]

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 coincide with CGA S-1.1 for DOT 39 cylinders 
offered for transportation after October 1, 2008; other DOT-
specification cylinders with the first requalification due after 
October 1, 2008; and UN pressure receptacles prior to initial use. 
Specifically, as prescribed in 4.2.2 of CGA S-1.1, the required burst 
pressure of the rupture disc ``shall not exceed 80% of the minimum 
cylinder burst pressure and shall not be less than 105% 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 this NPRM, PHMSA proposes 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 liquified oxidizing gases by air. PHMSA 
notes that the revision made to Sec.  173.301(f) was based on option 2 
presented in HMT Associates comment to rulemaking HM-218F and submitted 
as petition P-1580. PHMSA requests comments from the compressed gas 
industry regarding this course of action.

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) and Water Systems Council (WSC) 
standard PST-2000-2005(2009) to be authorized for transport.
    ANSI and WSC standard PST-2000-2005 is an industry standard that 
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[emsp14][deg]F (49 
[deg]C), with 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. Incorporating the standard into the HMR 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.
    PHMSA identified 38 U.S. based manufacturers or distributors of 
water pump system tanks, most of which would be classified as a small 
business using SBA size standards (<500 employees). There are no costs 
associated with this proposal because it is already incorporated into 
the regulations. This proposal will authorize tanks to be tested to 
current standards in the HMR or the manufacturer's specified minimum 
working pressure. Further, it allows water pump system tanks to be 
charged with helium in addition to the currently authorized nitrogen. 
The revisions would provide greater flexibility to stakeholders without 
compromising safety. Therefore, in this NPRM, PHMSA is proposing these 
recommended changes.

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 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 their manufacture, testing, operational parameters, and 
maintenance.
    PHMSA identified approximately 5,000 companies that would be 
subject to this standard, with the majority being classified as small 
businesses using SBA size standards (<500 employees).
    This minor update to the regulations improves the timeliness and 
clarity of industry standards that are IBR. It supports the goal of 
facilitating voluntary compliance and reducing the burdens associated 
with references to outdated material. Therefore, in this NPRM, PHMSA is 
proposing these recommended changes.

P-1596

    Chemically Speaking, LLC submitted P-1596 requesting that PHMSA 
revise the HMR pertaining to salvage drums. Specifically, they propose 
amending Sec.  173.3(d) to allow Class 4 and Class 5 materials to be 
placed in salvage cylinders.
    For over 30 years the gas industry, public agencies, gas cylinder 
users, and gas disposal companies have used open head salvage cylinders 
fabricated to ASME specifications to quickly and safely contain and 
transport leaking cylinders to locations where they can be safely 
emptied or repaired. Salvage cylinders were originally permitted under 
special permits (exemptions) specific for each design,\5\ but these 
exemptions were adopted into the HMR in 2005. Class 4 or 5 materials 
were not

[[Page 48989]]

included in the adoption; however, there is no preamble language in the 
rules specifically indicating reasons for the exclusion. A salvage 
cylinder made to ASME specifications as a pressure vessel and packaged 
as prescribed in Sec.  173.3(d) is a more robust package than a salvage 
container, which is used for liquids or solids. The addition of a 
pyrophoric material will not add a new hazard in the use of salvage 
cylinders, as some of the compressed gases that are also authorized 
have pyrophoric properties, such as silane, 2.1 (UN2203) or phosphine, 
2.3 (UN2199). Moreover, these gases also have the added hazards of high 
pressure (1,500 psig), with the latter also being a toxic material.
---------------------------------------------------------------------------

    \5\ DOT-E 9507, 9781, 9991, 10022, 10110, 10151, 10323, 10372, 
10504, 10519, 10789, 10987, 11257, 11459, 12698, 12790, and 12898.
---------------------------------------------------------------------------

    Over a period of four years (2006-2010), the use of salvage 
pressure receptacles was debated at the UN Subcommittee on 
Transportation of Dangerous Goods. Numerous papers were submitted in 
support of this effort. In the December 2010 session, the use of 
salvage pressure receptacles was approved and published in ``Amendments 
to the sixteenth revised edition of the Recommendations on the 
Transport of Dangerous Goods, Model Regulations.'' The amendments 
include the authorization of salvage cylinders for Class 4 and 5 
materials.
    This change will have a positive economic impact on owners of 
salvage cylinders as this will increase the instances where a salvage 
cylinder can be used. Many metal alkyl users and gas suppliers already 
own a salvage cylinder. There will be a negligible burden for 
procedures to be updated to include these cylinders. Therefore, in this 
NPRM, PHMSA is proposing these recommended changes; however, we do not 
propose additional reporting requirements.

P-1622

    Worthington Cylinders submitted P-1622 requesting that PHMSA allow 
the internal volume of DOT 39 cylinders not to exceed 75 cubic inches, 
which will be reflected in revisions to the entries for cyclopropane, 
ethane, and ethylene in the Sec.  173.304a(a)(2) table to include this 
limit in new footnote ``Note 9.'' This proposal would also clarify the 
75 cubic inch limit for DOT 39 cylinders by adding it in a new sentence 
to Sec.  173.304a(d)(3). Worthington Cylinders states its 
justifications for this petition are as follows:

    As discussed in my May 2011 letter, 49 CFR went through a 
rewrite in 2001. At this point in time, Paragraph 173.304 titled 
``Charging of cylinders with liquefied compressed gas'' was divided 
into two specific sections, 173.304 and 173.304a. Previous to the 
change in 2001, Note 9 was present in the Table of Paragraph 
173.304. This note stated ``When used for shipment of flammable 
gases, the internal volume of a Specification 39 cylinder must not 
exceed 75 cubic inches.'' This would apply specifically to cylinders 
containing liquefied compressed gases. At the same time, Paragraph 
173.302 titled ``Charging of cylinder with non-liquefied compressed 
gases'' stated in subsection 4 that for ``Specification 39 cylinders 
for flammable gases, the internal volume may not exceed 75 cubic 
inches.'' This paragraph would specifically pertain to cylinders 
charged with non-liquefied gases.
    The problem lies with each edition of 49 CFR published since 
2001. Paragraph 173.304a is not making any statement limiting the 
Specification 39 cylinder volume when charging the cylinder with 
liquefied flammable gases, yet paragraph 173.302a(3) limits the 
flammable compressed gas in a Specification 39 cylinder to a maximum 
of 75 cubic inches. Clearly, DOT would not want to authorize a 
liquefied flammable compressed gas for any volume Specification 39 
cylinder when the specifications limit the volume to 75 cubic inches 
for a flammable compressed gas. I will use propane as an example: 
Propane can be shipped as a compressed gas or a liquefied compressed 
gas. If it is shipped as a compressed gas the specifications limit 
the shipper to a container 75 cubic inches or smaller (49 CFR 
173.302). If the shipper was shipping propane as a liquefied 
compressed gas there are no limitations in the regulations on the 
Specification 39 cylinder volume (49 CFR 174.304a). This clearly 
makes no logical sense when propane expands 270 times its volume 
from a liquid to a vapor. Why would the stored energy for a 
Specification 39 cylinder with vapor be limited to 75 cubic inches 
and for a liquid have no limitations?
    Specification 39 cylinders have a proven track record. Millions 
of these cylinders have been manufactured and used for the safe and 
reliable storage and transportation of compressed gases and 
liquefied compressed gases. This proven safety and reliable track 
record includes 2.1 flammable liquefied compressed gases limited to 
75 cubic inch capacity. Worthington's concerns of using up to 1526 
cubic inch volume cylinders for 2.1 flammable liquefied compressed 
gases centers around the puncture resistance and corrosion 
resistance which are ``real life'' issues in the transportation of 
cylinders. Releasing basically four gallons of propane from a 
Specification 39 cylinder from a puncture or corrosion is not in the 
best interest of safety. Worthington strongly recommends that PHMSA 
review the following and consider it as immediate changes to 49 CFR 
173.304a and 173.304(d)(3).

    PHMSA agrees with the petitioner and will permit valves other than 
those listed in CGA S-1.1 to be used by adding the word ``may'' to this 
phrase in the regulatory text: ``a CG-7 pressure relief valve may be 
used.'' In this NPRM, PHMSA is proposing these recommended changes.
    Worthington Cylinders also asked PHMSA to explain what is meant by 
``chemical under pressure'' in Sec.  173.302a(a)(3) as it relates to 
this phrase: ``or 50L for chemical under pressure.'' Section 
173.302a(a) describes detailed filling requirements for the shipment of 
non-liquefied (permanent) compressed gases in specification cylinders. 
Specifically, Sec.  173.302a(a)(3) limits the capacity of a DOT 39 
cylinder to 1.23 L (75 in\3\) when the cylinder is filled with a 
Division 2.1 material or 50 L (3050 in\3\) when the cylinder is filled 
with a chemical under pressure. PHMSA revised Sec. Sec.  173.301b and 
173.302a in a final rule [Docket No. PHMSA-2012-0027 (HM-215L); 78 FR 
988] to increase the maximum allowable water capacity for non-
refillable cylinders containing chemicals under pressure to 50 liters 
(3050in\3\); therefore, this request has been addressed.
    The phrase in question was added to the HMR under a final rule 
published January 7, 2013 (HM-215L; 78 FR 988). Under that final rule 
we introduced new HMT entries for ``chemical under pressure,'' assigned 
authorized non-bulk and bulk packaging, and included other safety 
requirements such as quantity and filling limits. See Sec. Sec.  
172.102, Special Provision 362, and 173.335. In the HM-215L final rule 
(78 FR 989), PHMSA discussed a comment received from 3M in support of 
the proposal; however, 3M requested that PHMSA authorize the use of 
non-refillable cylinders (i.e., DOT 39s) larger than 1.25 liters 
containing flammable gas consistent with the UN Model Regulations. We 
noted our '' intent regarding the chemical under pressure entry was to 
comprehensively align the requirements of this entry with international 
standards.'' In the HM-215L final rule, we revised the packaging 
requirements for chemical under pressure to authorize the use of 
nonrefillable cylinders larger than 1.25 liters for chemical under 
pressure, hence, the inclusion of ``or 50L for chemical under 
pressure'' for DOT 39 cylinders in Sec.  173.302a(a)(3). This language 
applies to ``chemicals under pressure'' as described in Special 
Provision 362 and must not be applied to flammable gases. PHMSA is also 
looking to resolve the discrepancy created by this allowance for larger 
capacities for this cylinder type because it exceeds the size limits 
authorized under the design specifications for DOT 39 cylinders in 
Sec.  178.65. In this NPRM, PHMSA is proposing to revise Sec.  
173.302a(a)(3) to clarify any confusion on the applicable capacity 
limits.

P-1626

    The CGA submitted P-1626 requesting that PHMSA IBR CGA C-1,

[[Page 48990]]

Methods for Pressure Testing Compressed Gas Cylinders, Tenth Edition 
(2009) and revise the regulations regarding the 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. PHMSA is 
proposing to IBR this most current version and requests comment 
regarding this action.
    PHMSA identified approximately 980 entities that conduct 
hydrostatic testing, including cylinder requalifiers, retesters, and 
manufacturers.
    In this NPRM, PHMSA is proposing to adopt clarifying language and 
IBR the CGA C-1 standard, as proposed in P-1626, as it provides more 
detailed instructions and illustrations than what is possible in the 
HMR and addresses the deficiencies detailed in the petition. The CGA 
requests that this proposed IBR apply 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, 178.50, 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, 2016 supports the goal of increasing 
compliance and improving overall safety as its reference increases 
clarity, provides enhanced guidance, and reduces confusion between CGA 
current dates and IBR versions. 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. Revising the 
HMR to IBR CGA C-1 will provide the desired clarification without 
imposing requirements that are potentially costly or unnecessarily 
difficult.

P-1628

    The CGA submitted P-1628 requesting that PHMSA IBR CGA C-3-2005, 
Reaffirmed 2011, Standards for Welding on Thin-Walled, Steel Cylinders, 
Seventh Edition as material incorporated by reference in the HMR. 
Presently, the HMR reference CGA C-3-1994, Standards for Welding on 
Thin-Walled Steel Cylinders, Fourth Edition.
    This publication contains information on welding process 
qualification, welding operator qualifications, tensile testing, bend 
testing, and radiographic inspection. The changes between the C-3-1994, 
Fourth Edition and the C-3-2005, Reaffirmed 2011, Seventh Editions 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 this petition:
     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.
     Clarified the weld bend testing procedure, weld bend 
testing tooling, and proper clearances that are required in the 
tooling.
     Clarified definitions for the welding procedure 
qualification and the welding operator weld qualification.
     Added tolerance section to C-3-2005, Reaffirmed 2011 that 
indicates the plus and minus tolerances when a specific dimensional 
tolerance is indicated in the publication.
     Added drawings to the C-3-2005, Reaffirmed 2011 
illustrating different weld joint designs.
     Reviewed C-3-2005, Reaffirmed 2011 for conditional wording 
and revised it for enforceable wording.
    PHMSA identified approximately 5,000 companies that would be 
subject to this standard, with the majority being classified as small 
businesses using SBA size standards (<500 employees).
    This minor update to the regulations improves the timeliness and 
clarity of industry standards that are IBR. It supports the goal of 
facilitating voluntary compliance and reducing the burdens associated 
with references to outdated material. Therefore, in this NPRM, PHMSA is 
proposing these recommended changes.

P-1629

    The CGA submitted P-1629 requesting that PHMSA IBR CGA C-14-2005, 
Reaffirmed 2010, Procedures for Fire Testing of DOT Cylinder Pressure 
Relief Device Systems, Fourth Edition, as a material incorporated by 
reference in the HMR. Presently, the HMR reference CGA C-14-1979, 
Procedures for Fire Testing of DOT Cylinder Pressure Relief Device 
Systems, First Edition. 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). The procedures are applicable for 
cylinders that are less than 500 pounds water capacity and 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 this petition:
     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.
     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.
     Clarified what information is to be recorded before and 
during the actual test.
     Increased the water capacity of a cylinder that can be 
fire tested from 500 lb. water capacity to 1000 lbs. water capacity to 
permit a test method for all 4 series cylinders.
     Reviewed C-14-2005, Reaffirmed 2010 for conditional 
wording and modified it to replace conditional wording with enforceable 
wording, wherever appropriate.
    PHMSA identified approximately 5,000 companies that would be 
subject to this standard, with the majority being classified as small 
businesses using SBA size standards (<500 employees).
    This minor update to the regulations improves the timeliness and 
clarity of industry standards that are IBR. It supports the goal of 
facilitating voluntary compliance and reducing the burdens associated 
with references to outdated material. Therefore, in this NPRM, PHMSA is 
proposing these recommended changes.

P-1630

    The CGA submitted P-1630 requesting that PHMSA revise the HMR 
requirements for DOT 4L welded insulated cylinders. Specifically, the 
CGA requests PHMSA make two changes:
(1) Add a Definition for ``Recondition'' to Sec.  180.203
    The CGA states ``[t]he term `recondition' is distinct from work 
presently defined as repair or rebuild and describes work on a part or 
component of a DOT 4L welded insulated cylinder that does not involve 
repair or rebuilding of the inner containment vessel. For purposes of 
this

[[Page 48991]]

petition, the inner containment vessel refers to the term cylinder as 
defined in Sec.  171.8. In addition, DOT 4L welded insulated cylinder 
refers to that packaging defined in Sec.  178.57.'' The CGA did not 
propose language for the definition.
    The HMR prescribe the requirements for reconditioning DOT 4L 
cylinders in Sec.  180.211, further specifying additional requirements 
for rebuilding DOT 4L cylinders in paragraph (e). ``Recondition'' is a 
word that describes a process that applies to several cylinder 
packaging types under the HMR. PHMSA is concerned that adding a 
definition for ``recondition'' that applies only to DOT 4L 
specification cylinders would cause confusion that may reduce the safe 
application of these regulations. Therefore, PHMSA is not proposing in 
this NPRM to define a ``reconditioned cylinder'' in Sec.  180.203.
(2) 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 
as Interpreted in DOT Letters of Interpretation Reference Nos. 11-0237 
and 12-0065
    Reference No. 11-0237 states: ``[t]he term `rebuild' is defined in 
Sec.  180.203 as the replacement of a pressure part (e.g., a wall, 
head, or pressure fitting) by welding. While a `rebuild' would be 
required when the inner vessel of a DOT-4 series cylinder is 
compromised, it is not the only scenario that would constitute a 
`rebuild.' DOT-4 series cylinders requiring rebuild, as defined in 
Sec.  180.203, must do so in conformance with Sec.  180.211. In 
addition, DOT 4L cylinders must meet additional requirements for repair 
specified in Sec.  180.211(e) including proof pressure testing each 
inner containment vessel at two times its service pressure. DOT 4L 
cylinders which undergo procedures that are not defined as a rebuild in 
Sec.  180.203 are not subject to the requirements of Sec.  
180.203(e).''
    Reference No. 12-0065 states: ``[t]he term `repair' is defined in 
Sec.  180.203 as a procedure for correction of a condemned cylinder 
that may involve welding. A repair is not limited to the correction of 
a condemned cylinder that has had only its inner vessel compromised; 
therefore, DOT-4 series cylinders requiring repair, as defined in Sec.  
180.203, must be done in conformance with Sec.  180.211. In addition, 
DOT 4L cylinders must meet additional requirements for repair specified 
in Sec.  180.211(c) including being pressure-tested in conformance with 
the specifications under which the cylinder was originally 
manufactured. DOT 4L cylinders which undergo procedures that are not 
defined as a repair in Sec.  180.203 are not subject to the 
requirements of Sec.  180.211(c) including the requirement to be 
pressure-tested in conformance with the specifications under which the 
cylinder was originally manufactured.''
    The CGA notes its understanding that these DOT interpretations 
``state that testing the inner containment vessel after reconditioning, 
as defined below, are relatively new and prior to these interpretations 
no such testing had taken place.'' The CGA further notes that it 
``knows of no incidents related to the lack of such testing.''
    While the requirements the petitioner is referring to have existed 
since 2002 [67 FR 51626]--and prior to that to some extent in former 
Sec.  173.34--PHMSA agrees with the petitioner that adding language to 
clarify when a rebuilt DOT 4L cylinder and its components need to be 
pressure tested would make this requirement easier to understand; 
therefore, PHMSA is revising Sec.  180.211(c) to include the clarifying 
language about this requirement included in letter Reference No. 11-
0237.
    The CGA further states its ``purpose for requesting amendments to 
Sec. Sec.  180.211(c) and 180.211(e) is to clarify that certain work on 
parts and components of a DOT 4L welded insulated cylinder other than 
the inner containment vessel does not require hydrostatic testing of 
the inner containment vessel. The addition and definition of the term 
`recondition' with respect to these DOT 4L welded insulated cylinders 
identifies this work and enables verification of the integrity of such 
work using a pneumatic leak test at 90% of service pressure for which 
the DOT 4L welded insulated cylinder was designed and tested and by 
using a mass spectrometer detection system.''
    As previously stated, while this requirement has existed since 
2002, PHMSA agrees with the petitioner that revising the language in 
Sec.  180.211(e) to include the language in letter Reference No. 12-
0065 would improve the understanding of this requirement and, thereby, 
possibly improve safety.
    In this NPRM, PHMSA is proposing to amend Sec.  180.211(c) and (e) 
for clarification as petitioned.

IV. Special Permits

    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. We are no longer proposing 
changes in this NPRM 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).
    Since publication of the ANPRM, we have considered proposing 
revisions to the HMR based on adoption of DOT-SP 14237. For over ten 
years, PHMSA has authorized the use of certain non-bulk DOT-
specification cylinders to transport specific adsorbed gases under 
special permits. DOT-SP 14237, first issued on December 22, 2006, is 
general in its application in that it does not require the use of 
drawings and applications for DOT-specification cylinders that are 
specific to one company. Adopting this special permit would reduce 
costs associated with application and management, while also increasing 
safety and expanding the use of DOT-specification cylinders for 
adsorbed gases. PHMSA is not aware of any incident or investigation 
concerning the performance of packaging and transport under this 
special permit since its issuance; therefore, PHMSA is proposing in 
this NPRM to adopt the special permit into the HMR.
    Furthermore, PHMSA added provisions to the HMR for shipping 
adsorbed gases in a final rule issued on January 7, 2015 [Docket No. 
PHMSA-2013-0260 (HM-215M); 80 FR 1075] applicable to UN pressure 
receptacles. Specifically, these changes incorporated international 
standards designed to allow the transportation of certain gases when 
they are adsorbed onto a porous solid material in a non-bulk UN 
standard pressure receptacle. Two commenters to the HM-215M NPRM 
requested that PHMSA also permit adsorbed gases in DOT-specification 
cylinders. One commenter, Entegris, Inc., proposed regulatory text that 
includes DOT cylinder specifications and provisions not previously 
authorized under DOT special permit. PHMSA chose not to accept the 
comment and did not adopt the changes at that time; however, PHMSA 
invites the public to review Entegris, Inc.'s comments under Docket No. 
PHMSA-2013-0260 at www.regulations.gov and to comment on the safety and 
costs associated with its proposal and its possible inclusion under new 
Sec.  173.302d.

V. Agency Initiated Editorial Corrections

    In an ongoing attempt to improve safety, PHMSA regularly reviews 
and revises the HMR to correct errors and

[[Page 48992]]

clarify any regulations that are unclear or confusing. PHMSA is 
adopting the following issues of concern into this NPRM and seeks 
comment regarding the changes.

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 to 
verify inspections. However, at present, the application information 
requirements of Sec.  107.803(c)(3) only reference part 178. In this 
NPRM, PHMSA is proposing to revise Sec.  107.803(c)(3) to include part 
180, subpart C for consistency.

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 proposing to revise 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.

Section 178.70

    Section 178.70 provides approval for the manufacture of UN pressure 
receptacles (i.e., cylinders). Current 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 this NPRM, PHMSA 
is proposing to adopt language consistent with UN/ISO standards to 
reduce the need for approvals.

Section 180.203

    Section 180.203 specifies definitions that apply to cylinder use, 
qualification, and maintenance. PHMSA has encountered frequent problems 
regarding this section and is recommending the following revisions:
(1) Define and Incorporate ``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 operation 
is for a cylinder requalifier to be able to perform its requalifying 
function within a 100-mile radius of its primary place of business. To 
operate, a mobile cylinder requalifier must adhere to the requirements 
in a PHMSA-issued approval letter.
    Since companies may not be familiar with the option to offer mobile 
testing of cylinders to their customers through an approval by the 
Associate Administrator, PHMSA is proposing in this NPRM to add a 
definition of ``mobile unit'' to the HMR in Sec.  180.203 and a new 
paragraph in Sec.  107.805 identifying application requirements for 
mobile units. These proposed revisions would enhance requalifiers' 
ability to perform cylinder requalifications under the scope of the 
HMR.
(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. Not all retesters know that proof pressure 
testing allows the test to be performed with just air (no water), 
therefore taking approximately one-third the time of a modified hydro 
test without wasting water. The required test is only looking for leaks 
not determining a cylinder expansion percentage rate. We expect that 
use of a proof pressure will pass along cost savings to a requalifier.
    The HMR prescribes in Sec.  180.209(e) (for DOT 4-series cylinders) 
and (j) (for fire extinguishers) that a proof pressure test is 
authorized. In Sec.  180.203, proof pressure test is defined as ``a 
pressure test by interior pressurization without the determination of 
expansion of the cylinder'' (i.e., a leak test). In this NPRM, PHMSA is 
proposing to revise the definition of proof pressure test to specify 
that a liquid or a gas may be used to conduct the test. However, we 
note that the safety risk for conducting this test is substantially 
more using gas such as air versus a liquid such as water although this 
risk is lessened for low-pressure cylinders such as fire extinguishers. 
We seek comment on the impact of this revision and whether this 
clarification achieves the intent of enhancing compliance by specifying 
the air may be used for a proof pressure test. We also invite comment 
on a better method for communicating that a gas may be used for a proof 
pressure test, preferrable for low-pressure cylinders.

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). 
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. In addition, PHMSA Engineering staff is participating in an 
ISO/TC58/SC4 working group that is considering a revision to the ISO 
6406 standard to include pressure receptacles larger than 150 liters; 
therefore, PHMSA is proposing in this NPRM to add the phrase ``larger 
than 150 liters'' after ``including MEGC's pressure receptacles'' to 
clarify that the use of larger UN pressure receptacles is permitted 
under Sec.  180.207(d)(1).

Section 180.213

    Section 180.213 prescribes marking requirements for the visual 
inspection of cylinders (see Sec.  180.213 paragraphs (f)(5), (f)(8), 
and (f)(9)). In the past, PHMSA has allowed a visual (V) requalifier 
identification number (i.e., a V number) 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; 
however, PHMSA issues approval letters that permit a V number marking 
yet only provide three of the four available marking options and do not 
reference Sec.  180.213.
    Section 180.213 of the HMR should include the marking requirements 
for a V number consistent with those for an RIN. The V number could be 
placed in a square pattern as shown in Sec.  180.213. However, marking 
a V number, which is a single letter followed by six numbers, in a 
square pattern like an RIN, which is a single letter followed by three 
numbers, requires clarification, as the marks vary. Including the 
marking requirements for V numbers into Sec.  180.213 will make 
authorized options for these identifiers to be placed on a cylinder 
more widely understood.

[[Page 48993]]

PHMSA is proposing in this NPRM to include this V number marking in 
Sec.  180.213(g).

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 this NPRM, PHMSA is proposing 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.

VI. 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 
NPRM, we propose to revise Sec.  107.803(c)(3) to clarify that the 
applicant's description of his or her ability to perform and verify 
inspections must include those required under 49 CFR part 180, subpart 
C.

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 NPRM, we propose to add paragraph (c)(5) 
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 propose to make a conforming 
edit to paragraphs (c)(3) and (c)(4) by moving the ``and'' clause from 
paragraph (c)(3) to (c)(4).

Section 171.7

    Section 171.7 lists reference standards and regulations 
incorporated by reference into the HMR that are not specifically set 
forth in the HMR. Paragraph (g) incorporates into the HMR publications 
issued by the American Society of Mechanical Engineers, specifically, 
the ASME Boiler and Pressure Vessel Code. In this NPRM, we propose to 
revise the list of sections in paragraph (g)(1) to include Sec.  
173.302d based on the addition of this new section to the HMR and its 
reference to this standard in Sec.  173.302d(b)(11). Also, paragraph 
(n) specifically incorporates into the HMR publications issued by the 
Compressed Gas Association, an industrial and medical gas association 
that, among others, develops standards and practices for the safe 
transportation of gases and their containers. In this NPRM, we propose 
to add to Sec.  171.7(n) the latest CGA publication C-1, Methods for 
Pressure Testing Compressed Gas Cylinders. We also propose to 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. Also, note a weblink in the ADDRESSES 
section of the introduction to this rulemaking to review these 
publications during the comment period. The documents are summarized 
below.
    The ASME publication is 2015 ASME Boiler and Pressure Vessel Code 
(ASME Code) Section VIII--Rules for Construction of Pressure Vessels 
Division 1. The publication provides requirements applicable to the 
design, fabrication, inspection, testing, and certification of pressure 
vessels operation at either internal or external pressures exceeding 15 
psig. Division 1 also contains mandatory and nonmandatory appendices 
detailing supplementary design criteria, nondestructive examination and 
inspection acceptance standards. During the open comment period of this 
NPRM, this publication is freely available on the ASME Web site at: 
http://go.asme.org/PHMSA-ASME-PRM.
    The Compressed Gas Association publications include the following:
    (1) CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders 
(2016). During the open comment period of this NPRM, this publication 
is freely available on the CGA Web site at: https://www.cganet.com/customer/dot.aspx. 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). During the open comment period of this NPRM, 
this publication is freely available on the CGA Web site at: https://www.cganet.com/customer/dot.aspx. 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). During the open comment period of this NPRM, this 
publication is freely available on the CGA Web site at: https://www.cganet.com/customer/dot.aspx. 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). During the open comment 
period of this NPRM, this publication is freely available on the CGA 
Web site at: https://www.cganet.com/customer/dot.aspx. 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 are 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). During the open comment period of this 
NPRM, this publication is freely available on the CGA Web site at: 
https://www.cganet.com/customer/dot.aspx. 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.

[[Page 48994]]

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)(4) outlines requirements for filling of cylinders for 
export or use onboard a vessel. In this NPRM, we propose to revise the 
marking requirements consistent with changes made to Sec.  180.213.

Section 172.400a

    Section 172.400a(a)(1) prescribes exceptions from labeling for 
Dewar flasks or cylinders that comply with the provisions of this 
paragraph and are durably marked and labeled in conformance with CGA C-
7. In this NPRM, we propose to revise paragraph (a)(1) to clarify how 
this labeling exception applies to overpacks.

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 NPRM, we propose to permit cylinders that contain 
Class 4 or 5 materials to also use this exception. In addition, because 
of the proposal to include 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.

Section 173.301

    Section 173.301 provides the general requirements for shipment of 
compressed gases and other hazardous material in cylinders. In this 
NPRM, we propose to clarify the marking requirements of paragraph 
(a)(9), specifically use of the ``OVERPACK'' mark to indicate the 
combination packaging contains inner packagings that conform to 
specifications. Additionally, in paragraphs (c) and (f), we propose an 
editorial revision to the section citation of CGA S-1.1 to correctly 
read 9.1.1. Finally, we propose to revise paragraph (f) to clarify the 
minimum burst pressure requirements for DOT 39 cylinders used to 
transport compressed or liquefied oxidizing gases.

Section 173.302

    Section 173.302(a)(2) prescribes the requirements for adsorbed 
gases. In this NPRM, we propose to include references to new Sec.  
173.302d applicable to DOT-specification cylinders and to replace 
reference to ``UN cylinders'' with ``UN pressure receptacles'' for 
consistency with other parts of the HMR.

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 this NPRM, we propose to clarify the capacity (internal volume) 
requirements to make it clear that the 1.23 L limit applies to Division 
2.1 material and the 50 L limit applies to chemical under pressure 
classed as Division 2.1 (see Sec.  172.102, special provision 362). We 
also propose an editorial correction to the start of paragraph (a)(3) 
by removing the non-italicized ``DOT 39.''

Section 173.302d

    In this NPRM, we propose to add new Sec.  173.302d prescribing 
requirements for transportation of adsorbed gases in DOT-specification 
cylinders. The requirements of this new section are based on the 
adoption of special permit DOT-SP 14237 provisions.

Section 173.304a

    Section 173.304a prescribes the maximum permitted filling density 
and authorized cylinders for specific gases. In this NPRM, we propose 
to add new paragraph (a)(3) to Sec.  173.304a to clearly state that the 
maximum capacity (internal volume) of a DOT 39 cylinder containing 
liquefied flammable gas is 1.23 liters (75 in\3\). We also propose 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.

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 NPRM, we propose to 
revise Sec.  173.306(g) to authorize tanks to be tested to current 
standards in the HMR or the manufacturer's specified maximum working 
pressure, to allow water pump system tanks to be charged with helium, 
to clarify that transportation by aircraft is not an authorized mode of 
transport.

Section 173.309

    In this NPRM, we propose 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.

Section 173.312

    Section 173.312(b)(1) prescribes the filling requirements for 
multiple element gas containers (MEGCs). In this NPRM, we propose 
requirements for filling pressure receptacles containing liquefied 
compressed gas by weight.

Section 178.35

    Section 178.35(f) prescribes the marking requirements that apply to 
DOT-specification cylinders. In this NPRM, we propose to add new 
paragraph (f)(7) to Sec.  178.35 to require that cylinder tare weight 
or mass weight, and water capacity, be marked on certain DOT-
specification cylinders filled by weight.

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 NPRM, we propose to 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. 
We also propose to revise the format of the pressure testing paragraphs 
for greater consistency.

Sections 178.50, 178.51, 178.61, and 178.68

    These sections prescribe DOT 4-series specification requirements. 
These specifications are often unclear to manufacturers and enforcement 
personnel. In this NPRM, we propose to revise the specification 
requirements to promote consistent and uniform manufacturing practices 
for DOT 4-series cylinders.

Section 178.70

    Section 178.70(d) prescribes the requirements to obtain design 
approval of a UN pressure receptacle. In this NPRM, we propose to 
revise paragraph (d) to include language that an approval for a design 
modification is not required if the specific design modification is

[[Page 48995]]

covered under the UN/ISO standard for the design type already approved.

Section 180.203

    Section 180.203 prescribes definitions that apply to the 
qualification, maintenance, and use of cylinders under the HMR. In this 
NPRM, we propose to add new definitions for the terms or phrases 
``accuracy,'' ``accuracy grade,'' ``actual test pressure,'' 
``calibrated cylinder,'' ``error,'' ``master gauge,'' ``mobile unit,'' 
``overpressurized,'' ``percent permanent expansion,'' ``precision,'' 
``proof pressure test,'' ``reference gauge,'' and ``service pressure''; 
and revise the definitions for ``commercially free of corrosive 
components,'' ``defect,'' and ``test pressure.'' These proposed 
definitions will clarify the cylinder requirements prescribed in 49 CFR 
part 180, subpart C.

Section 180.205

    Section 180.205 prescribes the general requirements for 
requalifying DOT-specification cylinders. In this NPRM, we propose to 
revise and add new regulatory text for clarity. Specifically, we 
propose to clarify the conditions requiring test and inspection of 
cylinders under paragraph (d) by including a reference to evidence of 
grinding; revise the paragraph (f) visual inspection requirements to 
include reference to shot blasting and ``chasing'' of cylinders; 
clarify and revise the paragraph (g) retest equipment tolerances for 
consistency with ISO standards 6406 and 10461 (i.e., standards for 
periodic inspection and testing of gas cylinders) which are both 
incorporated by reference in the HMR in Sec.  180.207 to allow for 
broader use of retest equipment (we invite comment on this course of 
action relative to the tolerances provided for in CGA C-1); revise the 
paragraph (i) cylinder condemnation requirements to clarify the 
responsibilities of the requalifier and add conditions under which a 
cylinder must be condemned; and include a reference to training 
materials, under new paragraph (j), that are suitable for training 
persons who requalify cylinders using the volumetric expansion test 
method.

Section 180.207

    Section 180.207 prescribes requirements for requalifying UN 
pressure receptacles. In this NPRM, we propose to revise and add new 
regulatory text for clarity. Specifically, we propose to clarify the 
language prohibiting the use of a UN pressure receptacle beyond its 
service life by, for example, removing approval authorization language; 
to revise the requalification procedures for seamless steel cylinders 
to include MEGC pressure receptacles larger than 150 liters water 
capacity; and to revise the requalification schedule for dissolved 
acetylene UN cylinders to be requalified no sooner than five years and 
no later than ten years from the date of manufacture.

Section 180.209

    Section 180.209 prescribes requirements for requalifying 
specification cylinders. In this NPRM, we propose to revise and add new 
regulatory text for clarity; and to incorporate the current version of 
CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders. 
Specifically, we propose to revise the paragraph (a) table 1 to include 
reference to the paragraph (e) conditions for an alternate 
requalification period; the paragraph (b) conditions for star-marking 
of a DOT 3A or 3AA cylinder; and the paragraph (m) requalification 
conditions for DOT 3AL cylinders made of 6351-T6 aluminum alloy.

Section 180.211

    Section 180.211 prescribes requirements to repair, rebuild, and 
reheat treat DOT-4 series specification cylinders. In this NPRM, we 
propose to clarify that the requirements to repair DOT 4L cylinders in 
paragraph (c) of this section are for rebuilding the cylinders and to 
clarify paragraph (e) for when a hydrostatic test may be performed on 
the inner containment vessel of a DOT 4L welded insulated cylinder. We 
do not propose in this NPRM to add a definition for ``recondition'' to 
Sec.  180.203 because of our concern that adding this definition for 
only DOT 4L cylinders might cause further confusion and reduce safety.

Section 180.212

    Section 180.212(a) prescribes requirements to repair seamless DOT 
3-series specification cylinders and seamless UN pressure receptacles. 
In this NPRM, we propose to require an ultrasonic examination on DOT 3-
series cylinders and seamless UN pressure receptacles after any 
grinding is performed on these cylinders.

Section 180.213

    Section 180.213 prescribes requirements for marking DOT-
specification cylinders and UN pressure receptacles that are 
successfully requalified. In this NPRM, we propose to revise the 
requalification marking method to clarify the steps involved and that 
stamping the sidewall of the cylinder is prohibited. Additionally, we 
propose to clarify the marking requirements for foreign cylinders 
filled for export under paragraph (d) and to include two new marking 
requirements under paragraph (f) for designation of grinding with 
ultrasonic wall thickness examination and for designation of 
requalification of a foreign cylinder requalified in conformance with 
Sec. Sec.  171.23(a)(4) and 180.209(l) of this subchapter. Finally, we 
propose to add visual inspection identifier number marking requirements 
under a new paragraph (g).

Section 180.215

    Section 180.215 prescribes reporting and retention requirements for 
a person who requalifies, repairs, or rebuilds cylinders. In this NPRM, 
we propose to clarify what information these documents must contain.

49 CFR Part 180, Appendix C

    Part 180, appendix C prescribes the requirements eddy current 
examination equipment must meet to inspect DOT 3AL, 6351-T6 aluminum 
alloy cylinders. In this NPRM, we propose to retitle the appendix and 
revise paragraph 1 for clarity regarding equipment calibration 
procedures when conducting eddy current examination.

VII. Regulatory Analyses and Notices

A. Statutory/Legal Authority for This NPRM

    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.'' 
Section 5117(a) authorizes the Secretary to issue a special permit 
exempting compliance with a regulation prescribed in Sec. Sec.  
5103(b), 5104, 5110, or 5112 ``to a person transporting, or causing to 
be transported, hazardous material in a way that achieves a safety 
level at least equal to the safety level required under [the Federal 
hazmat law], or consistent with the public interest . . . if a required 
safety level does not exist.'' The issues described in this NPRM 
respond to 20 outstanding petitions for rulemaking.

B. Executive Order 12866, Executive Order 13563, and DOT Regulatory 
Policies and Procedures

    This NPRM is not considered a significant regulatory action under 
section 3(f) of Executive Order 12866 (``Regulatory Planning and 
Review'') and was not reviewed by the Office of Management and Budget 
(OMB).

[[Page 48996]]

Neither was it considered a significant rule under the Regulatory 
Policies and Procedures order issued by the Department of 
Transportation [44 FR 11034].
    Executive Order 13563 (``Improving Regulation and Regulatory 
Review'') is ``supplemental to and reaffirms the principles, 
structures, and definitions governing regulatory review that were 
established in Executive Order 12866 of September 30, 1993.'' In 
addition, Executive Order 13563 specifically requires agencies to: (1) 
Involve the public in the regulatory process; (2) promote 
simplification and harmonization through interagency coordination; (3) 
``identify and consider regulatory approaches that reduce burdens and 
maintain flexibility''; (4) ensure the objectivity of any scientific or 
technological information used to support regulatory action; and (5) 
consider how to best promote retrospective analysis to modify, 
streamline, expand, or repeal existing rules that are outmoded, 
ineffective, insufficient, or excessively burdensome.
    PHMSA has involved the public in the regulatory process by (1) 
addressing issues identified for possible future rulemaking in letters 
of interpretation and other correspondence, and (2) responding to 20 
petitions for rulemaking submitted by stakeholders in the compressed 
gas industry in conformance with 49 CFR 106.95. Overall, the issues 
discussed in this NPRM promote the continued safe transportation of 
hazardous materials while producing a net benefit.
    These petitions clarify the existing regulatory text in the HMR, 
incorporate widely used industry publications, and address specific 
safety concerns, thus enhancing the safe transportation of compressed 
gases while limiting the impact on the regulated community. 
Incorporating the provisions of special permits into regulations with 
general applicability will provide shippers and carriers with 
additional flexibility to comply with established safety requirements, 
thereby reducing burdens and costs and increasing productivity.
    Further, PHMSA on its own initiative is clarifying existing 
regulatory language to reduce misunderstandings that will thereby 
improve safety. Some of the proposed changes are summarized below, by 
topic.
Incorporating Updated CGA C-6, Visual Inspection of Steel Cylinders
    PHMSA proposes to replace the currently incorporated Seventh 
Edition of the CGA 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.
    Under the HMR, compressed gas cylinders must be visually inspected 
as part of the requalification process once every five years. CGA C-6 
serves as a guide to cylinder requalifiers and users for establishing 
cylinder inspection procedures and standards. The Tenth Edition 
provides updated and enhanced guidance on the inspection of multi-
element gas containers, cylinder thread inspection for cylinders used 
in corrosive gas service, and clarified maximum allowable depths and 
measuring techniques for various types of corrosion.
    PHMSA identified approximately 5,000 companies that would be 
subject to this standard. The majority of these companies are 
classified as small businesses using SBA size standards. This revision 
would impose a one-time individual cost for purchase of the updated 
standard. We assume that the majority of companies subject to this 
standard are non-CGA members or non-CGA subscribers. Assuming 
approximately 5,000 companies purchase the Eleventh Edition of CGA-6, 
we estimate the upper bound of the total cost across all affected 
entities for this proposal would be approximately $710,000.
    The benefit of this change is that it would improve the clarity of 
industry standards that are currently incorporated by reference. It 
facilitates voluntary compliance and reduces the burdens associated 
with references to outdated material. PHMSA believes that these changes 
may yield an incremental improvement to the overall safety of hazmat 
cylinder transportation. In comments made to the ANPRM, five 
stakeholders support the proposal to update the IBR of CGA C-6 to the 
Tenth Edition. No commenters objected to the proposal or provided 
benefit data.
Incorporating CGA C-1 Methods of Pressure Testing Compressed Gas 
Cylinders Into the HMR
    PHMSA proposes to revise the HMR regarding the retesting of 
cylinders using pressure testing. The HMR is often perceived as unclear 
on procedures and requirements for pressure testing of cylinders. 
Incorporating by reference CGA C-1, Methods for Pressure Testing 
Compressed Gas Cylinders clarifies ambiguities in the HMR.
    It is estimated that this would affect approximately 980 entities 
that conduct pressure testing, including cylinder requalifiers, 
retesters, and manufacturers. PHMSA estimates a one-time compliance 
cost of $186 for each entity purchasing the Eleventh Edition of CGA C-
1. The upper bound of the total cost across all affected entities for 
this proposal would be approximately $182,280. Actual costs are 
expected to be lower, as some of the 980 entities may be members, 
subscribers, or already own the revised edition. Revising the HMR to 
incorporate CGA C-1 would increase clarity, reduce confusion, provide 
enhanced guidance, and provide marginal safety benefits without 
imposing requirements that are potentially costly or difficult.
Weight Marking Requirements for Filling of DOT 4-Series Specification 
Cylinders
    PHMSA proposes to require newly manufactured DOT 4B, 4BA, 4BW, and 
4E cylinders to be marked with the tare weight or the mass weight and 
the water capacity. Accurate cylinder tare weight, or mass weight, and 
water capacity are crucial for safe filling and transportation of 
cylinders containing liquefied compressed gas. Overfilled cylinders 
have the potential for leakage and possible failure during transport.
    PHMSA identified six U.S. based manufacturers of the cylinders. 
Five of these companies are classed as small businesses using SBA size 
standards. The HMR already incorporate by reference NFPA 58, LP Gas 
Code, which requires cylinders used for liquefied petroleum gases to be 
marked with the tare weight and water capacity. The NFPA 58 does not 
specify how the cylinders must be marked, nor does it specify by whom. 
Further, NFPA 58 only addresses liquefied petroleum gas, not all 
liquefied compressed gases. We do not anticipate significant additional 
costs to DOT 4-series-specification cylinders, manufacturers, or 
owners, because many in the liquefied compressed gas industry already 
request that manufacturers mark cylinders with this additional 
information as an added safety measure.
Clarify Filling Limits on Multiple Element Gas Containers
    PHMSA proposes to clarify filling limits for a liquefied compressed 
gas in a manifold comprised of DOT-specification cylinders or a 
multiple element gas container (MEGC). Specifically, liquefied 
compressed gases contained in manifold cylinders cannot exceed the 
filling densities specified in Sec.  173.304a(a)(2) and liquefied gases 
in MEGCs comprised of UN pressure receptacles must not exceed the 
values contained in P200 as specified in Sec.  173.304b.
    This proposed change will remove the discrepancy between the set 
pressure

[[Page 48997]]

specified in CGA S-1.1 and the differing set pressures prescribed in 
Sec. Sec.  173.302(f)(2) and 173.304(f)(2). This revision would not 
impose any new costs on affected industries, and although the proposed 
revision restates a requirement from another section in the HMR, we 
believe it would provide additional protection against overfilling of a 
cylinder. This change would promote regulatory compliance and foster 
safe filling practices.

C. Executive Order 13132

    This proposed rule has been analyzed in accordance with the 
principles and criteria contained in Executive Order 13132 
(``Federalism'') and the President's memorandum (``Preemption'') that 
was published in the Federal Register on May 22, 2009 [74 FR 24693]. 
This proposed rule will preempt State, local, and Native America 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, 49 U.S.C. 5101-
5128, contains an express preemption provision [49 U.S.C. 5125 (b)] 
that preempts State, local, and Native American tribal requirements on 
the following subjects:
    (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;
    (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.
    PHMSA invites those with an interest in the issues presented in 
this NPRM to comment on the effect the adoption of specific proposals 
may have on State or local governments.

D. Executive Order 13175

    This NPRM was analyzed in accordance with the principles and 
criteria contained in Executive Order 13175 (``Consultation and 
Coordination with Indian Tribal Governments''). Because this NPRM does 
not have tribal implications and does not impose substantial direct 
compliance costs on Native American tribal governments, the funding and 
consultation requirements of Executive Order 13175 do not apply, and a 
tribal summary impact statement is not required. We invite Native 
American tribal governments to provide comments on the effect the 
adoption of specific proposals may have on Indian communities.

E. 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. The term 
``small entities'' 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. (See 5 U.S.C. 601.) This notice has 
been developed in accordance with Executive Order 13272 (``Proper 
Consideration of Small Entities in Agency Rulemaking'') and DOT's 
Policies and Procedures to promote compliance with the Regulatory 
Flexibility Act to ensure that potential impacts of draft rules on 
small entities are properly considered. Section 603(b) of the 
Regulatory Flexibility Act requires an analysis of the possible impact 
of the proposed 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 NPRM is as follows:
1. Need for the NPRM
    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 NPRM is part of a 
retrospective analysis to modify and streamline existing requirements 
that are outmoded, ineffective, insufficient, or excessively 
burdensome. This rulemaking also introduces new provisions suggested or 
developed by industry representatives, industry groups that develop 
standards, or international regulatory bodies.
2. Description of Action
    This NPRM considers incorporating the provisions of one special 
permit, responds to 20 petitions for rulemaking, considers clarifying 
other requirements in the HMR, and addresses areas of concern that are 
currently left out of the HMR. The amendments discussed in this NPRM 
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 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, 541380). Nearly all of these companies, particularly cylinder 
requalification facilities of which there are approximately 5,000, are 
small entities based on the criteria developed by the Small Business 
Administration.
4. Reporting and Recordkeeping Requirements
    This NPRM does not include any new reporting or 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 
NPRM 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 29 CFR. 
With respect to the transportation of compressed gases in cylinders, 
there are not related rules or regulations issued by other

[[Page 48998]]

departments or agencies of the Federal government.
6. Alternative Proposals for Small Business
    Certain regulatory actions may affect the competitive situation of 
an individual company or group of companies by imposing relatively 
greater burdens on small, rather than large, enterprises. PHMSA 
requests comments from small entities on the impacts of these 
additional requirements.
7. Conclusion
    This NPRM requests information that will be used to develop a 
proposal to amend provisions of the HMR addressing the manufacture, 
maintenance, and use of cylinders. PHMSA anticipates that the proposals 
in this NPRM will reduce burdens for most persons and any costs 
resulting from adoption of new requirements will be offset by the 
benefits derived from eliminating the need to apply for special 
permits, increasing regulatory flexibility, and improving safety 
through enhanced compliance. If your business or organization is a 
small entity and the adoption of the proposals contained in this NPRM 
could have a significant economic impact on your operations, please 
submit a comment explaining how and to what extent your business or 
organization could be affected.

F. Paperwork Reduction Act

    This NPRM does not impose new information collection requirements. 
Depending on the results of our request for comments to this NPRM, 
there may be a decrease in the annual burden and costs under OMB-
proposed changes to incorporate provisions contained in certain widely 
used or longstanding special permits with an established safety record.
    PHMSA specifically requests comments on the information collection 
and recordkeeping burdens associated with developing, implementing, and 
maintaining these requirements for approval under this NPRM.
    Address written comments to the Dockets Unit as identified in the 
ADDRESSES section of this NPRM. We must receive comments regarding 
information collection burdens prior to the close of the comment period 
identified in the DATES section of this NPRM.

G. 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.

H. Unfunded Mandates Reform Act of 1995

    This NPRM does not impose unfunded mandates under the Unfunded 
Mandates Reform Act of 1995. It does not result in costs of $141.3 
million or more to either State, local, or tribal governments, in the 
aggregate, or to the private sector and is the least burdensome 
alternative that achieves the objective of the rule. Further, in 
compliance with the Unfunded Mandates Reform Act of 1995, PHMSA will 
evaluate any regulatory action that might be proposed in subsequent 
stages of the proceeding to assess the effects on State, local, and 
tribal governments and the private sector.

I. 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 NPRM responds to 20 petitions for rulemaking submitted by the 
regulated community and seeks comment on incorporating the provisions 
of one special permit. The issues discussed in this NPRM would, if 
eventually adopted, 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 and 
condemnation requirements for cylinders.
    This NPRM discusses the following amendments to the HMR:
     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 Tenth Edition and update the 
appropriate references throughout the HMR.
     Revise the manufacturing requirements for certain DOT-4 
series cylinders.
     Revise the requirements for the requalification of DOT-
specification cylinders by pressure testing found in 49 CFR part 180, 
subpart C.
     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 
(currently IBR in the HMR) appendix A on cylinders contained in 
overpacks.
     Require manufacturers to mark newly manufactured cylinders 
suitable for the transport of liquefied compressed gas with the mass 
weight or tare weight, and water capacity.
     Allow non-specification cylinders used in a fixed fire 
suppression system to be transported under the same exceptions as those 
provided for fire extinguishers.
     Permit use of the OVERPACK marking for cylinders packed in 
conformance with Sec.  173.301(a)(9).
     Clarify filling limits for a liquefied compressed gas in a 
manifold or a multiple element gas container (MEGC).
     Clarify the requirements for filling non-specification 
cylinders for export or use on board a vessel.
     Add requirements for DOT-specification cylinders used to 
transport adsorbed gases.
2. Alternatives Considered
    Alternative (1): Do nothing. Our goal is to 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 
do-nothing alternative.
    Alternative (2): Preferred choice. With this alternative, PHMSA 
will publish an NPRM seeking public comment on the issues raised in 20 
petitions for rulemaking and the incorporation of one special permit; 
review the comments received on the amendments described in the ANPRM 
and their potential economic and safety implications; and use these 
comments to craft more specific proposals that are published in this 
NPRM. This is the selected alternative.

[[Page 48999]]

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. 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. Hazardous 
materials are categorized by hazard analysis and experience into hazard 
classes and packing groups. The regulations require each shipper to 
classify a material in accordance with these hazard classes and packing 
groups. The process of classifying a hazardous material is itself a 
form of hazard analysis. Further, the regulations require the shipper 
to communicate a material's hazards through the use of hazard class, 
packing group, and proper shipping name on the shipping paper and the 
use of labels on packages and placards on transport vehicles. Thus, the 
shipping paper, labels, and placards communicate the most significant 
findings of the shipper's hazard analysis. A hazardous material is 
assigned to one of three packing groups based upon its degree of 
hazard, from a high hazard material (Packing Group I) to a low hazard 
material (Packing Group III). The quality, damage resistance, and 
performance standards of the packaging in each packing group are 
appropriate for the hazards of the material transported.
    Under the HMR, hazardous materials are transported by aircraft, 
vessel, rail, and highway. 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.
    It is anticipated that the petitions and special permits discussed 
in this NPRM if adopted in a future rulemaking, 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 NPRM and determined that the amendments considered would 
provide protection against the release of hazardous materials based on 
sound scientific methods and would not result in unusual stresses on 
the cylinder or adversely impact human health or the environment. PHMSA 
welcomes any data or information related to environmental impacts, both 
positive and negative, that may result from a future rulemaking 
addressing the issues discussed in this NPRM.

J. 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.

K. International Trade Analysis

    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 NPRM to ensure that it does not 
exclude imports that meet this objective. As a result, this NPRM is not 
considered as creating an unnecessary obstacle to foreign commerce.

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 172

    Education, Hazardous materials transportation, Hazardous waste, 
Incorporation by reference, Labeling, Markings, Packaging and 
containers, 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, Motor vehicle 
safety, Packaging and containers, Railroad safety, Reporting and 
recordkeeping requirements.

    In consideration of the foregoing, PHMSA is proposing to amend 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 (28 U.S.C. 2461 note); Pub. L. 104-121, sections 212-213; Pub. L. 
104-134, section 31001; Pub. L. 112-141 section 33006; 49 CFR 1.81 
and 1.97.

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 part 178 and part 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 (c)(4), and add 
paragraph (c)(5) to read as follows:

[[Page 49000]]

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 (28 U.S.C. 2461 note); Pub. L. 104-121, sections 212-213; Pub. L. 
104-134, section 31001; 49 CFR 1.81 and 1.97.

0
5. In Sec.  171.7, revise paragraphs (g)(1) and (n) to read as follows:

Sec.  171.7  Reference material.

* * * * *
    (g) * * *
    (1) 2015 ASME Boiler and Pressure Vessel Code (ASME Code), 2015 
Edition, July 1, 2015 (as follows), into Sec. Sec.  172.102; 173.3; 
173.5b; 173.24b; 173.302d; 173.306; 173.315; 173.318; 173.420; 178.255-
1; 178.255-2; 178.255-14; 178.255-15; 178.273; 178.274; 178.276; 
178.277; 178.320; 178.337-1; 178.337-2; 178.337-3; 178.337-4; 178.337-
6; 178.337-16; 178.337-18; 178.338-1; 178.338-2; 178.338-3; 178.338-4; 
178.338-5; 178.338-6; 178.338-13; 178.338-16; 178.338-18; 178.338-19; 
178.345-1; 178.345-2; 178.345-3; 178.345-4; 178.345-7; 178.345-14; 
178.345-15; 178.346-1; 178.347-1; 178.348-1; 179.400-3; 180.407.
* * * * *
    (n) Compressed Gas Association (CGA), 1235 Jefferson Davis Highway, 
Arlington, VA 22202.
    (1) CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders, 
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, Standards for Welding on Thin-Walled Steel Cylinders, 
2005 (Reaffirmed 2011), 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.
    (3) CGA C-5, Cylinder Service Life--Seamless Steel High Pressure 
Cylinders, 1991 (Reaffirmed 1995), into Sec.  173.302a and 180.209.
    (4) CGA C-6, Standards for Visual Inspection of Steel Compressed 
Gas Cylinders, 2013, into Sec. Sec.  172.102, 173.3, 173.198, 173.302d, 
180.205, 180.209, 180.211, 180.411, 180.519.
    (5) CGA C-6.1, Standards for Visual Inspection of High Pressure 
Aluminum Compressed Gas Cylinders, 2002, into Sec. Sec.  180.205; 
180.209.
    (6) CGA C-6.2, Guidelines for Visual Inspection and Requalification 
of Fiber Reinforced High Pressure Cylinders, 1996, into Sec.  180.205.
    (7) CGA C-6.3, Guidelines for Visual Inspection and Requalification 
of Low Pressure Aluminum Compressed Gas Cylinders, 1991, into 
Sec. Sec.  180.205; 180.209.
    (8) CGA C-7, Guide to Preparation of Precautionary Labeling and 
Marking of Compressed Gas Containers, Appendix A, issued 2004, into 
Sec.  172.400a.
    (9) CGA C-8, Standard for Requalification of DOT-3HT Cylinder 
Design, 1985, into Sec. Sec.  180.205; 180.209.
    (10) CGA C-11, Recommended Practices for Inspection of Compressed 
Gas Cylinders at Time of Manufacture, 2001, into Sec.  178.35.
    (11) CGA C-12, Qualification Procedure for Acetylene Cylinder 
Design, 1994, into Sec. Sec.  173.301; 173.303; 178.59; 178.60.
    (12) CGA C-13, Guidelines for Periodic Visual Inspection and 
Requalification of Acetylene Cylinders, 2000, into Sec. Sec.  173.303; 
180.205; 180.209.
    (13) CGA C-14, Procedures for Fire Testing of DOT Cylinder Pressure 
Relief Device Systems, 2005 (Reaffirmed 2010), into Sec. Sec.  173.301; 
173.323.
    (14) CGA G-1.6, Standard for Mobile Acetylene Trailer Systems, 
2011, in Sec.  173.301(g).
    (15) CGA G-2.2, Guideline Method for Determining Minimum of 0.2% 
Water in Anhydrous Ammonia, 1985, Reaffirmed 1997, into Sec.  173.315.
    (16) CGA G-4.1, Cleaning Equipment for Oxygen Service, 1985, into 
Sec.  178.338-15.
    (17) CGA P-20, Standard for the Classification of Toxic Gas 
Mixtures, 2003, Third Edition, into Sec.  173.115.
    (18) CGA S-1.1, Pressure Relief Device Standards--Part 1--Cylinders 
for Compressed Gases, (except paragraph 9.1.1), 2011, into Sec. Sec.  
173.301; 173.304a; 178.75.
    (19) CGA S-1.2, Safety Relief Device Standards Part 2--Cargo and 
Portable Tanks for Compressed Gases, 1980, into Sec. Sec.  173.315; 
173.318; 178.276; 178.277.
    (20) CGA S-7, Method for Selecting Pressure Relief Devices for 
Compressed Gas Mixtures in Cylinders, 2005, into Sec.  173.301.
    (21) CGA TB-2, Guidelines for Inspection and Repair of MC-330 and 
MC-331 Cargo Tanks, 1980, into Sec. Sec.  180.407; 180.413.
    (22) CGA TB-25, Design Considerations for Tube Trailers, 2008, into 
Sec.  173.301.
* * * * *
0
6. In Sec.  171.23, revise paragraph (a)(4)(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) * * *
    (4) * * *
    (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 172--HAZARDOUS MATERIALS TABLE, SPECIAL PROVISIONS, HAZARDOUS 
MATERIALS COMMUNICATIONS, EMERGENCY RESPONSE INFORMATION, TRAINING 
REQUIREMENTS, AND SECURITY PLANS

0
7. The authority citation for part 172 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.  172.400a, revise paragraph (a)(1) to read as follows:

Sec.  172.400a  Exceptions from labeling.

* * * * *
    (a) * * *
    (1) A Dewar flask meeting the requirements in Sec.  173.320 of this 
subchapter, or a cylinder containing a Division 2.1, 2.2, or 2.3 
material, that is durably and legibly marked in conformance with CGA C-
7, appendix A (IBR; see Sec.  171.7 of this subchapter). However, if 
overpacked, marking (or appropriate labels) must be communicated on the 
exterior of the overpack unless visible from the outside in accordance 
with Sec.  173.25 of this subchapter.
* * * * *

[[Page 49001]]

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

0
9. 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
10. In Sec.  173.3, revise paragraph (d)(1) to read as follows:

Sec.  173.3  Packaging and exceptions.

* * * * *
    (d) * * *
    (1) Except for Class 1, Class 7, or acetylene material, a cylinder 
containing a hazardous material may be overpacked in a salvage 
cylinder.
* * * * *
0
11. In Sec.  173.301:
0
a. Revise paragraphs (a)(9) and (f)(4); and
0
b. In paragraphs (c) and (f), replace ``9.1.1.1'' with ``9.1.1'' in 
each place it appears.
    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.

    (a) * * *
    (9) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 
39 cylinders must be packed in strong non-bulk outer packagings. The 
outside of the combination package must be marked with an indication 
that the inner packagings conform to the prescribed specifications. 
Except for Specification 2P and 2Q containers, the ``OVERPACK'' marking 
in accordance with Sec.  173.25(a)(3) of this part may be used to 
satisfy the marking requirement of this paragraph. Display of the 
``OVERPACK'' marking is not an indication that this combination package 
is an overpack.
* * * * *
    (f) * * *
    (4) DOT 39 cylinders. (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) Notwithstanding the requirements of paragraph (f)(1) of this 
section with respect to the minimum burst pressure of pressure relief 
devices, a pressure relief device on a DOT 39 cylinder used to 
transport compressed or liquefied oxidizing gases may have a minimum 
burst pressure within the range prescribed in Sec. Sec.  173.302(f)(2) 
or 173.304(f)(2), as appropriate.''
* * * * *
0
12. In Sec.  173.302, revise paragraph (a)(2) to read as follows:

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

    (a) * * *
    (2) Adsorbed gas. A cylinder filled with an adsorbed gas must be 
offered for transportation in conformance with the requirements of 
paragraph (d) of this section and Sec.  173.301 of this subpart. In 
addition, UN pressure receptacles must meet the requirements in 
Sec. Sec.  173.301b, 173.302b, and 173.302c of this subpart, as 
applicable, and DOT-specification cylinders must meet the requirements 
of Sec. Sec.  173.301a, 173.302a and 173.302d, as applicable, of this 
subpart. Where more than one section applies to a cylinder, the most 
restrictive requirements must be followed.
* * * * *
0
13. In Sec.  173.302a, revise paragraph (a)(3) 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 
1.25 L (75 in\3\). For chemical under pressure (see Sec.  172.102, 
special provision 362 of this subchapter), the internal volume may not 
exceed 50 L (3050 in\3\).
* * * * *
0
14. Add Sec.  173.302d to read as follows:

Sec.  173.302d  Additional requirements for the shipment of adsorbed 
gases in DOT-specification cylinders.

    (a) General. A cylinder filled with an adsorbed gas must be offered 
for transportation in DOT-specification cylinders subject to the 
requirements in this section, and Sec. Sec.  173.301 and 173.302 of 
this subpart.
    (b) Packaging. (1) DOT-3E1800, DOT-3AA2015, and DOT-3AA2265 
cylinders must be used with a capacity between 0.4 and 7.3 liters.
    (2) Each cylinder authorized by this section must remain in 
dedicated product service for its entire life.
    (3) The maximum pressure inside each cylinder must be 0 psig at 
70[emsp14][deg]F and 30 psig at 140[emsp14][deg]F.
    (4) The contents of the cylinders must be limited in pressure and 
volume so that if totally discharged into the overpack cylinder, the 
pressure in the overpack cylinder will not exceed \5/4\ of the MAWP at 
55 [deg]C (131[emsp14][deg]F).
    (5) The valve wheel of each cylinder must be secured by a strap 
that provides tension in the tightening direction. A plug must be 
placed in each valve and the cylinder and valve area must be shrink-
wrapped before being placed in the overpack cylinder. A protective 
valve cap must be used on all pressure vessels except the DOT-3E1800 
cylinder. Valves on the DOT-3E1800 cylinders must be protected in 
conformance with Sec.  173.40(d) of this part.
    (6) Prior to each shipment, the leak integrity of the overpack 
cylinder must be verified and have a leak rate no greater than 1 x 
10-4 standard atmospheric cubic centimeters per second.
    (7) All closures of the overpack cylinder shall have a method to 
determine if they have been tampered with during transportation. The 
pressure indicating device on the overpack cylinder may be used to 
indicate tampering.
    (8) The shipper must instruct the carriers to reject or remove the 
overpack cylinder from transportation in the event that the pressure 
gauge drops below a pressure designated by the shipper.
    (9) Each overpack cylinder must be labeled for the hazardous 
material it contains.
    (10) Adsorbent material. Each cylinder is filled with a monolith 
solid microporous sorbent and/or bead-type sorbent onto which the gas 
is adsorbed. The gas remains adsorbed during transportation in 
essentially a solid state. The system is filled, operated, and 
transported at sub-atmospheric pressures and is described as a sub-
atmospheric gas delivery system (SDS). The gas must be removed from the 
SDS using the input of external energy, such as a steady vacuum.
    (11) Overpack. (i) Cylinders authorized under this section must be 
transported in a non-DOT-specification full-opening, hinged-head or 
fully removable head, steel overpack cylinder. The overpack cylinder 
must be constructed to Section VIII, Division 1 of the ASME Code (IBR; 
see Sec.  171.7 of this subchapter) with a minimum design margin of 4 
to 1. The minimum MAWP must be 75 psig. The maximum water capacity must 
be 450 L (119 gallons). The overpack cylinder must not be equipped with 
a pressure relief device. The cylinders must be securely positioned 
within the overpack to prevent excessive movement. The overpack 
cylinder must have gaskets, valves and fittings that are compatible

[[Page 49002]]

with the hazardous materials they contain. The overpack cylinder must 
have a pressure gauge clearly visible from the outside. The pressure 
gauge must be recessed into the overpack cylinder or otherwise 
protected from damage during transportation. The overpack cylinder must 
be pressurized to 3-5 psig with inert gas.
    (ii) Overpack testing. Each overpack cylinder must be visually 
inspected in conformance with CGA C-6 (IBR; see Sec.  171.7 of this 
subchapter) at least once every five years. In addition, each overpack 
must be pressure tested to a minimum test pressure of at least 1.5 
times MAWP. The pressure must be maintained for at least 30 seconds. 
The cylinder must be examined under test pressure and removed from 
service if a leak or defect is found. The retest and inspection must be 
performed by a person trained and experienced in the use of the 
inspection and testing equipment.
    (iii) Overpack marking. Each overpack cylinder that is successfully 
requalified must be durably and legibly marked with the word ``Tested'' 
followed by the requalification date (month/year). The marking must be 
in letters and numbers at least 12 mm (0.5 inches) high. Stamping on 
the overpack sidewall is not permitted. The requalification marking may 
be placed on any portion of the upper end of the cylinder near the 
marking required by the following method, or on a metal plate 
permanently secured to the cylinder. The outside of each overpack 
cylinder must be plainly and durably marked on any portion of the upper 
end with ``OVERPACK CYLINDER'' (in lieu of the ``OVERPACK'' marking 
requirement of Sec.  173.25(a)(4) of this part), the proper shipping 
name of the hazardous material contained inside the overpack, the name 
and address of the consignee or consignor, and the name and address or 
registered symbol of the overpack manufacturer.
    (iv) Recordkeeping. The person who tested the overpack or that 
person's agent must retain a record of the most recent visual 
inspection and pressure test of the overpack until the cylinder is 
requalified. The records must be made available to a DOT representative 
upon request.
    (12) Sub-atmospheric gas delivery system (SDS) testing. Each 
cylinder, except DOT-3E cylinders, must be retested by persons trained 
to perform this procedure. DOT-3AA cylinders must be retested and 
marked in conformance with the requirements for DOT-3AA cylinders in 49 
CFR part 180 or the requirements of a current DOT special permit for 
ultrasonic examination.
    (c) Gases. The gases permitted to be transported as adsorbed in 
DOT-specification cylinders in conformance with this section are:

----------------------------------------------------------------------------------------------------------------
   Proper shipping name/hazardous     Hazard  class/
        materials description            division          Identification No.                Hazard zone
----------------------------------------------------------------------------------------------------------------
Arsine..............................             2.3  UN 2188.....................  Zone A.
Boron Trifluoride...................             2.3  UN 1008.....................  Zone B.
Hydrogen Selenide, Anhydrous........             2.3  UN 2202.....................  Zone A.
Liquefied Gas, Toxic, Corrosive,                 2.3  UN 3308.....................
 n.o.s. (Arsenic Pentafluoride).
Liquefied Gas, Toxic, Corrosive,                 2.3  UN 3308.....................  Zone B.
 n.o.s. (Germanium Tetrafluoride).
Liquefied Gas, Toxic, Corrosive,                 2.3  UN 3308.....................
 n.o.s. (Phosphorus Trifluoride).
Phosphine...........................             2.3  UN 2199.....................  Zone A.
Silicon Tetrafluoride...............             2.3  UN 1859.....................  Zone B.
----------------------------------------------------------------------------------------------------------------

0
15. In Sec.  173.304a, add paragraph (a)(3) to read as follows:

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

    (a) * * *
    (3) The internal volume of a DOT 39 cylinder may not exceed 1.23 
liters (nominal 75 in\3\) for a liquefied flammable gas. This cylinder 
shall be equipped with a pressure relief device as defined by the 
commodity in CGA S-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.
* * * * *
0
16. In Sec.  173.306, revise paragraph (g) to read as follows:

Sec.  173.306  Limited quantities of compressed gases.

* * * * *
    (g) Water pump system tank. A water pump system tank charged with 
compressed air or limited quantities of nitrogen or helium to not over 
40 psig for single trip shipment to an installation site is 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 subpart F (placarding) 
requirements 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, with heads concave to 
pressure, having a rated water capacity not exceeding 120 gallons and 
with an outside diameter not exceeding 24 inches. Safety relief devices 
are not required.
    (2) The tank must be pneumatically tested to the manufacturer's 
specified maximum working pressure. The test pressure must be 
permanently marked on the tank.
    (3) The stress at prescribed pressure for steel tanks must not 
exceed 20,000 psi (or 25,000 psi for deep-draw steel), concave dome 
tanks using the formula:

S = Pd/2t

Where:

S = wall stress in psi:
P = prescribed pressure for the tank of at least three (3) times 
charged pressure at 70[emsp14][deg]F or 100 psig, whichever is 
greater;
d = inside diameter in inches;
t = minimum wall thickness, in inches.

    (4) For composite tanks, the minimum value of a hydrostatic leak 
test, per design, must be at least six (6) times the charge pressure at 
70 [deg]F or three (3) times the manufacturer's specified maximum 
working pressure, whichever is greater.
    (5) For steel and composite tanks, the burst pressure must be at 
least six (6) times the charge pressure at 70 [deg]F or three (3) times 
the manufacturer's specified maximum working pressure, whichever is 
greater.
    (6) Each tank must be over-packed in a strong outer packaging in 
conformance with Sec.  173.301(h) of this part.
    (7) Transportation is limited to motor vehicle, railcar, and 
vessel. Transportation by aircraft is not authorized.
* * * * *
0
17. In Sec.  173.309, revise the introductory text to read as follows:

[[Page 49003]]

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. 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 forklift or crane when loaded 
or unloaded.
* * * * *
0
18. In Sec.  173.312, revise paragraph (b)(1) to read as follows:

Sec.  173.312  Requirements for shipment of MEGCs.

* * * * *
    (b) * * *
    (1) An MEGC being filled with a liquefied compressed gas must have 
each cylinder filled separately by weight. Manifolding during filling 
is not authorized. The filling density for DOT-specification cylinders 
may not exceed the values contained in Sec.  173.304a(a)(2) of this 
subpart and for UN pressure receptacles may not exceed the values in 
accordance with Sec.  173.304b(b) of this subpart.
* * * * *

PART 178--SPECIFICATIONS FOR PACKAGINGS

0
19. 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.

0
20. In Sec.  178.35, add paragraph (f)(7) to read as follows:

Sec.  178.35  General requirements for specification cylinders.

* * * * *
    (f) * * *
    (7) Tare weight or mass weight, and water capacity marking. DOT-
specification 4B, 4BA, 4BW, and 4E cylinders manufactured after January 
1, 2017, 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 at the time of manufacture must 
ensure it is marked with the following information, as applicable:
    (i) Tare weight. The tare weight for a cylinder 25 pounds (11.34 
kg) 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 (11.34 kg) 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, or
    (ii) Mass weight. The mass weight for a cylinder 25 pounds (11.34 
kg) 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 (11.34 kg) 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); and
    (iii) Water capacity. The water capacity for a cylinder 25 pounds 
(11.34 kg) water capacity or less, with a tolerance of minus 1 percent 
and no upper tolerance; or for a cylinder exceeding 25 pounds (11.34 
kg) water capacity, with a tolerance of minus 0.5 percent and upper 
tolerance. The marked water capacity of the cylinder must be the 
capacity of the cylinder at the time of manufacture.
* * * * *
0
21. 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent, volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
* * * * *
0
22. 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent, volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
* * * * *
0
23. 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 Pamphlet C-1. 
All testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA Pamphlet 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.
    (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

[[Page 49004]]

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 
at a pressure increased by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
    (5) 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 water-jacket, direct expansion or proof pressure 
test methods as defined 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. The cylinders must be subjected to at least 2 times service 
pressure and show no defect. Determination of expansion properties is 
not required.
* * * * *
0
24. 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 CGAC-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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *
0
25. In Sec.  178.42, revise paragraph (f) to read as follows:

Sec.  178.42  Specification 3E seamless steel cylinders.

* * * * *
    (f) Pressure testing. Cylinders must withstand a pressure test as 
follows:
    (1) Lot Testing. One cylinder out of each lot of 500 or fewer must 
be subjected to a test pressure of 6,000 psig or higher. The testing 
equipment must be calibrated as prescribed in CGA Pamphlet C-1. All 
testing equipment and pressure indicating devices must be accurate 
within the parameters defined in CGA Pamphlet C-1
    (2) Pressure Testing. The remaining cylinders of the lot must be 
pressure tested by water jacket, direct expansion or proof pressure 
method as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this 
subchapter). The cylinders must be examined under pressure of at least 
3,000 psig and not to exceed 4,500 psig and show no defect. The test 
pressure must be maintained for at least 30 seconds and sufficiently 
longer to ensure complete examination.
    (3) Burst Testing. (i) The cylinder 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 (6) 
times wall thickness between knife edges, wedge shaped 60-degree angle, 
rounded out to a half-inch radius. The inspector's report must be 
suitably changed to show results of latter alternate and flattening 
test.
    (ii) The cylinders in paragraph (f)(2) tested at a pressure in 
excess of 3,600 psig must burst at a pressure higher than 7,500 psig.
* * * * *
0
26. 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 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *
0
27. 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *
0
28. 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:

[[Page 49005]]

    (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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower. If the test apparatus 
again fails to maintain the test pressure, the cylinder being tested 
must be condemned. Any internal pressure applied to the cylinder before 
any official test may not exceed 90 percent of the test pressure.
    (4) Permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
* * * * *
0
29. In Sec.  178.47, revise paragraph (j) to read as follows:

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

* * * * *
    (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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of the 
total volumetric expansion at test pressure.
    (5) Cause for condemnation. Following the pressure test, the 
cylinder must be inspected. A cylinder with wall thickness less than 
that required by paragraph (f) of this section must be condemned. 
Bulges and cracks are cause for condemnation. Welded joint defects 
exceeding requirements of paragraph (k) of this section are cause for 
condemnation.
* * * * *
0
30. 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 psi for cylinders without longitudinal seam.
    (ii) 22,800 psig for cylinders having copper brazed or silver alloy 
brazed longitudinal seam.
    (iii) 18,000 psi 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 psi;
P = minimum test pressure prescribed for water jacket test or 450 
psig whichever is the greater;
D = outside diameter in inches;
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:

[[Page 49006]]

    (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 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (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 water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. The minimum test pressure must be 
maintained for a specific timeframe as prescribed 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 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 subpart C of this part. 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 of 
material taken 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 the purpose of strain measurement, the initial strain 
reference must be set while the specimen is under a stress of 12,000 
psi, and strain indicator reading must be set at the calculated 
corresponding strain.
    (iv) Cross-head speed of the testing machine may not exceed 18 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 20 
percent elongation. However, elongation percentages may be reduced 
numerically by one (1) percentage for each 7,500 psi increase of 
tensile strength above 50,000 psi. The tensile strength may be 
incrementally increased by a maximum total of 30,000 psi.
    (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-deqree 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 same 
heat of material taken 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[emsp14][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 condemned.
    (n) Condemned cylinders. (1) Unless otherwise stated in this 
section, if a

[[Page 49007]]

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 condemned.
    (2) Reheat treatment of a condemned cylinder. Reheat treatment is 
authorized for a condemned cylinder in accordance with this paragraph. 
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 
of this subpart 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;
    (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[emsp14][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
31. 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 appreciably weaken the finished cylinder. 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[emsp14][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 
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 psi; 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 psi;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches;
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 psi;
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 girth weld area and heat affected zones which zone 
must extend a distance of 6 times wall thickness from center line of 
weld);
E = 1.0 (for all other areas).

[[Page 49008]]

    (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 Sec.  178.51(m) 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[emsp14][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, 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) 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (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 water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. The minimum test pressure must be 
maintained for a 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.
    (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 as illustrated in appendix A to 
subpart C of this part.
    (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 of material taken as the as the spheres themselves. 
Samples must be removed as illustrated in appendix A to subpart C of 
this part.
    (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 in connection with 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 the purpose of strain measurement, the initial strain 
reference must be set while the specimen is under a stress of 12,000 
psi, 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 psi increase of tensile strength above 50,000 psi. The 
tensile strength may be incrementally increased by a maximum total of 
30,000 psi.
    (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

[[Page 49009]]

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 of material 
taken 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 (IBR, see 
Sec.  171.7 of this subchapter). 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 any of 
these latter two specimens fail to meet the requirements, the entire 
lot represented must be condemned.
    (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 (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 
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 condemned.
    (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 condemned.
    (m) Condemned cylinders.
    (1) Unless otherwise stated in this section, 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 additional 
specimens fails the test, then the entire lot must be condemned.
    (2) Reheat treatment of a condemned cylinder. Reheat treatment is 
authorized for a condemned cylinder in accordance with this paragraph. 
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 of 
this subpart 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) Embossing the cylinder head or side is not permitted.
0
32. 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) Each 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (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 water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. The minimum test pressure must be 
maintained for a 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.
* * * * *
0
33. 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

[[Page 49010]]

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 at a pressure increased by 10 percent or 100 
psig, whichever is lower.
    (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 water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. The minimum test pressure must be 
maintained for a 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. 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.
    (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 condemned.
* * * * *
0
34. 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) 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (v) If a 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 water-jacket, direct expansion or proof pressure test 
methods as prescribed in CGA C-1. The minimum test pressure must be 
maintained for a 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. A cylinder showing a defect must 
be condemned unless it may be requalified under paragraph (m) of this 
section.
* * * * *
0
35. 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 water-jacket, direct expansion, 
or proof pressure test methods 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) There must be no evidence of leakage, visible distortion or 
other defect.
* * * * *
0
36. 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of the 
total volumetric expansion at test pressure.
* * * * *
0
37. 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

[[Page 49011]]

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 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (v) If the tested cylinder fails, each cylinder remaining in the 
lot may be tested in lieu of paragraph (h)(2) of this section by the 
water-jacket or direct expansion method as prescribed in CGA C-1. Those 
passing are acceptable.
    (2) Pressure testing. (i) The remaining cylinders in each lot must 
be pressure tested by the water-jacket, direct expansion or proof 
pressure test methods as prescribed in CGA C-1. The minimum test 
pressure must be maintained for a 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 between 500 and 600 psig and show 
no defect.
* * * * *
0
38. 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) Each 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of 
the total volumetric expansion at test pressure.
    (v) If the tested cylinder fails, each remaining cylinder in the 
lot may be tested in lieu of paragraph (j)(2) of this section by the 
water-jacket or direct expansion method as prescribed in CGA C-1. Those 
passing are acceptable.
    (2) Pressure testing. (i) The remaining cylinders in each lot must 
be pressure tested by the water-jacket, direct expansion or proof 
pressure test methods as prescribed in CGA C-1. The minimum test 
pressure must be maintained for a 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 between 500 and 600 psig and show 
no defect.
* * * * *
0
39. 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 (g)(4) 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. 
Lap 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 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).
    (e) Welding of attachments. The attachment to the tops and bottoms 
only of cylinders by welding of neckrings,

[[Page 49012]]

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) Non-destructive examination. (1) Welds of the cylinders must be 
subjected to radioscopic or radiographic examination as follows:
    (2) 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 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 girth weld for 2 inches in both directions from 
the intersection of the longitudinal and girth welds and include at 
least 6 inches of the longitudinal weld. Maximum joint efficiency of 
0.75 will be permissible without radiography. When fluoroscopic 
examination is used, permanent film records need not be retained.
    (g) 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 (g)(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 (k) of this section.
    (iii) 35,000 psi.
    (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, psi;
P = service pressure, psig;
D = outside diameter, inches;
d = inside diameter, inches;
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).
    (h) 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 Sec.  
178.51(m) of this subpart 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[emsp14][deg]F in any part of the top or 
bottom material.
    (i) 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.
    (j) Pressure testing. Each cylinder must successfully withstand a 
pressure test as follows:
    (1) Lot testing. (i) At least one 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 (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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (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 water-jacket, direct expansion or proof 
pressure test methods as prescribed in CGA C-1. The minimum test 
pressure must be maintained for a 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.
    (3) Burst testing. (i) One finished cylinder selected at random out 
of each lot of 500 or less must be hydrostatically tested to four (4) 
times service pressure without bursting.
    (k) 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 illustrated in appendix A to subpart C of this part, chosen at 
random from each lot of 200 or fewer, as follows:
    (i) Body specimen. One specimen must be taken longitudinally from 
the body section at least 90 degrees away from the weld.
    (ii) Head specimen. 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\

[[Page 49013]]

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 the purpose of strain measurement, the initial strain 
reference must be set while the specimen is under a stress of 12,000 
psi, 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.
    (l) Elongation. Mechanical test specimens must show at least a 20 
percent elongation. However, elongation percentages may be reduced 
numerically by one (1) for each 7,500 psi of tensile strength above 
50,000 psi to a maximum of four (4) increments (i.e., 30,000 psi).
    (m) 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 condemned.
    (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 psi, as provided in paragraph (l) of this 
section. Should this specimen fail to meet the requirements, one 
additional specimen such 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 condemned.
    (n) 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 condemned cylinders. Reheat treatment is 
authorized for a condemned cylinder in accordance with this paragraph. 
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.
    (o) Markings. (1) Markings must be as required in Sec.  178.35 of 
this subpart 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 at least \1\/
16-inch thick and must be attached by welding at a 
temperature of 1,100[emsp14][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.
    (p) Inspector's report. In addition to the information required by 
Sec.  178.35 of this subpart, the inspector's report must indicate the 
type and amount of radiography.
0
40. In Sec.  178.65, revise paragraph (f) to read as follows:

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 a 
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.
    (2) The leakage test must be conducted by submersion under water or 
by some other method that will be equally sensitive.
    (3) If the cylinder leaks, evidences visible distortion or 
evidences any other defect while under test, it must be condemned (see 
paragraph (h) of this section).
* * * * *
0
41. In Sec.  178.68:
0
a. Revise paragraphs (b), (e), (h), (j) introductory text, (j)(1), (k), 
(l) and (m);
0
b. Redesignate paragraph (n) as paragraph (o); and

[[Page 49014]]

0
c. Add new paragraph (n).
    The revisions, redesignation, and addition read as follows:

Sec.  178.68  Specification 4E welded aluminum cylinders.

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

                      Table 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.
------------------------------------------------------------------------

    Note to Table 1: The aluminum used in the construction of the 
cylinder must be as specified in Table 1. 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) All cylinders with a wall stress greater than 18,000 psi 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (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 psi or 
less may be lot tested. At least one 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.
    (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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (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 psi or less, the remaining cylinders of the lot must be pressure 
tested by the water-jacket, direct expansion or proof pressure test 
methods as defined in CGA C-1. The minimum test pressure must be 
maintained for a 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.
    (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 service pressure without bursting. Inability to meet this 
requirement must result in condemnation of the lot.
* * * * *
    (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 subpart C of 
this part 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 a minimum tensile strength as defined 
in paragraph (f)(1)(ii) of this section, an elongation to at least 7 
percent and yield strength not over 80 percent of tensile strength.
    (l) Weld tests. Welds of the cylinder are required to successfully 
pass the following tests:
    (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 at least 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 condemned 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 condemned.
    (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) 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 condemned.
    (ii) Alternate guided bend test. This test may be used as an 
alternate to the

[[Page 49015]]

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 condemned.
    (m) Condemned 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 condemned.
    (2) 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 of 
this subpart 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
42. 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.
* * * * *

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. Add definitions for the words ``accuracy,'' ``accuracy grade,'' 
``actual test pressure,'' ``calibrated cylinder,'' ``error,'' ``master 
gauge,'' ``mobile unit,'' ``over-pressurized,'' ``percent permanent 
expansion,'' ``precision,'' ``proof pressure test,'' ``reference 
gauge,'' and ``service pressure'' in alphabetical order; and
0
b. Revise the definition for the words ``commercially free of corrosive 
components,'' ``defect,'' and ``test pressure.''
    The additions and revisions read as follows:

Sec.  180.203  Definitions

* * * * *
    Accuracy means the conformance of a particular reading to a known 
standard. Accuracy is expressed as the percentage of error from, or 
degree of closeness to, the true value, such as the difference between 
the measurement result displayed by the instrument and the value 
obtained when a measurement standard is used to perform the 
measurement. This value may be represented as a percent of full scale.
    Accuracy grade means the inherent quality of the device. It 
expresses the maximum error allowed for the device at any reading. 
Accuracy grade is expressed as a percentage of the full scale of the 
device.
    Actual test pressure means the pressure applied to a cylinder 
during a requalification test.
    Calibrated cylinder means a cylinder that has certified calibration 
points of pressure with corresponding expansion values. It is a 
secondary, derived standard used for the verification and demonstration 
of test system accuracy and integrity.
    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).
* * * * *
    Defect means an imperfection requiring a cylinder to be rejected or 
condemned.
* * * * *
    Error means the difference between the measured values and the true 
value.
* * * * *
    Master gauge means a pressure indicating device that is used as a 
calibration standard, has an inherent accuracy grade equal to or better 
than the requirement for the pressure indicating device in the test 
apparatus, and is an instrument not used in the daily performance of 
cylinder testing.
    Mobile unit means a vehicle specifically authorized under a RIN to 
carry out requalification operations identified under the RIN within a 
geographic area no more than 100 miles from the principle place of 
business of the RIN holder. 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.
    Percent permanent expansion means the ratio of permanent expansion 
to total expansion, expressed as a percentage. The calculation for 
percent permanent expansion is the permanent expansion divided by total 
expansion times 100.
* * * * *
    Precision of a measurement means the degree of scatter of the 
recorded values when the measurement is repeated a number of times 
under the same conditions.
    Proof pressure test means a pressure test by interior 
pressurization without the determination of a cylinder's expansion. A 
gas (e.g., air) or a liquid (e.g., water) is used as a means to achieve 
interior pressurization.
* * * * *
    Reference gauge means a pressure indicating device that is used in 
the daily verification of a proof test system, and has an inherent 
accuracy equal to or better than the requirement for the device to be 
checked.
* * * * *
    Service pressure means the rated service pressure marked on the 
cylinder.
    Test pressure means the minimum prescribed pressure required for 
the requalification of a cylinder.
* * * * *
0
45. In Sec.  180.205:
0
a. Revise paragraphs (c) introductory text, (d), (g)(3), (h)(3), 
(i)(1)(viii), (i)(2), and (i)(3); and
0
b. Add paragraphs (f)(5), (f)(6), (i)(1)(ix), (i)(1)(x), (i)(1)(xi) and 
(j).
    The additions and revisions read as follows:

[[Page 49016]]

Sec.  180.205  General requirements for requalification of 
specification cylinders.

* * * * *
    (c) Periodic requalification of cylinders. Each cylinder bearing a 
DOT-specification marking must be requalified and marked as specified 
in the Requalification Table in this subpart. 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). 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 
conformance 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 as provided in Sec.  180.212 of this subpart, the 
cylinder shows evidence of grinding; or
    (5) The Associate Administrator determines that the cylinder may be 
in an unsafe condition.
* * * * *
    (f) * * *
    (5) Shot blasting of cylinders is permitted. Grinding, sanding, or 
any other removal of wall thickness of a cylinder is not permitted, 
except by an authorized facility, as provided in Sec.  180.212 of this 
subpart for the removal of surface corrosion.
    (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 of this subpart.
    (g) * * *
    (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 (PID), as part of the retest 
equipment, is accurate within 1.0% of the prescribed test 
pressure of any cylinder tested that day. The PID must meet Industrial 
Class 1 (1.0% deviation from the end value) with a scale 
appropriate to the test pressure of the cylinder. The accuracy of the 
PID within the test system can be demonstrated at any point within 500 
psig of the actual test pressure for test pressures at or above 3,000 
psig, or 10% of the actual test pressure for test pressures below 3,000 
psig.
    (ii) The expansion-indicating device (EID), as part of the retest 
equipment, gives a stable reading of expansion and is accurate to 
1.0% of the total expansion of any cylinder tested or 0.1 
cc, whichever is larger. The EID must be accurate (1.0% 
deviation from the end value) of its full scale. The weigh scales must 
be capable of providing total expansion measurements to an accuracy of 
1.0% or 0.05 ounce (1.5 g), whichever is greater.
* * * * *
    (h) * * *
    (3) Unless the cylinder is repaired or rebuilt in conformance with 
requirements in Sec.  180.211of this subpart, 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.
    (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 X's 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 (such as CGA C-1.1; see 
Sec.  171.7, Table I of this subchapter) 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, (d)(1), and (d)(3) 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, but must be 
condemned in accordance with Sec.  180.205(i)(x) of this subpart.
    (b) * * *
    (2) Each pressure receptacle that fails requalification must be 
condemned in conformance with Sec.  180.205(i) of this subpart or 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) 
of this subpart. Alternative methods (e.g., acoustic emission) or 
requalification procedures may be

[[Page 49017]]

performed if prior approval has been obtained in writing from the 
Associate Administrator.
    (1) Seamless steel: Each seamless steel UN pressure receptacle, 
including MEGC's pressure receptacles exceeding 150 L capacity, must be 
requalified in conformance with ISO 6406 (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 
conformance with ISO 6406.
* * * * *
    (3) Dissolved acetylene UN cylinders: Each dissolved acetylene 
cylinder must be requalified in conformance with ISO 10462 (IBR, see 
Sec.  171.7 of this subchapter). The porous mass and the shell must be 
requalified no sooner than five (5) years and no later than ten (10) 
years from the date of manufacture. Thereafter, subsequent 
requalifications of the shell must be performed at least once every ten 
(10) years.
* * * * *
0
47. In Sec.  180.209, revise paragraphs (a), (b), (c), (e), (g), (l)(1) 
and (m) to read as follows:

Sec.  180.209  Requirements for requalification of specification 
cylinders.

    (a) Periodic qualification of cylinders. Each specification 
cylinder that becomes due for periodic requalification, as specified in 
the following table, must be requalified and marked in conformance with 
the requirements of this subpart before it is filled. Requalification 
records must be maintained in conformance with Sec.  180.215 of this 
subpart. Table 1 follows:

                  Table 1--Requalification of Cylinders
------------------------------------------------------------------------
  Specification under which       Minimum test         Requalification
      cylinder was made       pressure  (psig) \1\     period  (years)
------------------------------------------------------------------------
DOT 3.......................  3000 psig...........  5.
DOT 3A, 3AA.................  5/3 times service     5, or 12 (see Sec.
                               pressure, except      180.209(b), (f),
                               noncorrosive          (h), and (j)).
                               service (see Sec.
                               180.209(g)).
DOT 3AL\2\..................  5/3 times service     5, or 12 (see Sec.
                               pressure.             Sec.   180.209(j)
                                                     and (m)).
DOT 3AX, 3AAX...............  5/3 times service     5
                               pressure.
3B, 3BN.....................  2 times service       5 or 10 (see Sec.
                               pressure (see Sec.    180.209(f)).
                                180.209(g)).
3E..........................  Test not required...
3HT.........................  5/3 times service     3 (see Sec.  Sec.
                               pressure.             180.209(k) and
                                                     180.213(c)).
3T..........................  5/3 times service     5.
                               pressure.
4AA480......................  2 times service       5 or 10 (see Sec.
                               pressure (see Sec.    180.209(h)).
                                180.209(g)).
4B, 4BA, 4BW, 4B-240ET......  2 times service       5, 10, or 12 (see
                               pressure, except      Sec.   180.209(e),
                               non-corrosive         (f), and (j)).
                               service (see Sec.
                               180.209(g)).
4D, 4DA, 4DS................  2 times service.....  5.
DOT 4E......................  2 times service       5 or 10 ((see Sec.
                               pressure, except      Sec.   180.209(e)).
                               non-corrosive (see
                               Sec.   180.209(g)).
4L..........................  Test not required...
8, 8AL......................  ....................  10 or 20 (see Sec.
                                                     180.209(i)).
Exemption or special permit   See current           See current
 cylinder.                     exemption or          exemption or
                               special permit.       special permit.
Foreign cylinder (see Sec.    As marked on          5 (see Sec.  Sec.
 173.301(j) of this            cylinder, but not     180.209(l) and
 subchapter for restrictions   less than 5/3 of      180.213(d)(2)).
 on use).                      any service or
                               working pressure
                               marking.
------------------------------------------------------------------------
\1\ For cylinders not marked with a service pressure, see Sec.
  173.301a(b) of this subchapter.
\2\ For special permit (or exemption) aluminum cylinders marked DOT 3AL,
  see Sec.   173.23(c) of this subchapter.

    (b) DOT 3A or 3AA cylinders. (1) A cylinder conforming to 
specification DOT 3A or 3AA with a water capacity of 56.7 kg (125 
pounds) or less may be marked with a star and requalified every 10 
years instead of every 5 years, provided the cylinder conforms to all 
of the following conditions:
    (i) The cylinder is used exclusively for air; argon; cyclopropane; 
ethylene; helium; hydrogen; krypton; neon; nitrogen; nitrous oxide; 
oxygen; sulfur hexafluoride; xenon; chlorinated hydrocarbons, 
fluorinated hydrocarbons, liquefied hydrocarbons, and mixtures thereof 
that are commercially free from corroding components; permitted 
mixtures of these gases (see Sec.  173.301(d) of this subchapter); and 
permitted mixtures of these gases with up to 30 percent by volume of 
carbon dioxide, provided the gas has a moisture content less than 55 
ppm.
    (ii) The cylinder is not used in any cascade, bank, group, rack or 
vehicle. The cylinder is not used in self-contained underwater 
breathing apparatus (SCUBA), self-contained breathing apparatus (SCBA), 
or in an emergency respirator.
    (iii) The permanent expansion does not exceed 5 percent of the 
total expansion.
    (iv) The results of the hydrostatic test meet one of the following 
requirements:
    (A) The elastic expansion does not exceed the manufacturer's marked 
rejection elastic expansion (REE) limit on the cylinder;
    (B) The elastic expansion does not exceed the applicable rejection 
limit tabulated in CGA C-5 (IBR, see Sec.  171.7 of this subchapter); 
or
    (C) Either the average wall stress or the maximum wall stress does 
not exceed the corresponding wall stress limitation determined by 
computing the REE limit in conformance with CGA C-5.
    (v) The cylinder is dried immediately after hydrostatic testing to 
remove all traces of water.
    (vi) The cylinder is stamped with a five-pointed star at least one-
fourth of an inch high immediately following the test date to indicate 
compliance with this paragraph (b)(1).
    (2) If a cylinder has not been used exclusively for the gases 
specifically identified in paragraph (b)(1)(i) of this section, but 
currently conforms with all other provisions of paragraph (b)(1) of 
this section, it may be requalified every 10 years instead of every 5 
years, only after the cylinder has been retested, marked, and placed 
into exclusive use and gas service in compliance with paragraph (b)(1) 
of this section.
    (3) If, at any time, a cylinder marked with a five-pointed star is 
used in a manner other than as specified in paragraph (b)(1) of this 
section, the star following the most recent test date must be 
obliterated. The cylinder must be requalified within five years from 
the

[[Page 49018]]

marked test date, or if the required five-year requalification period 
has passed, the cylinder must be requalified prior to the first filling 
with a compressed gas.
    (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) Proof pressure test. 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 or proof pressure testing every 10 
years instead of every 5 years. 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. When subjected to a proof pressure test, as 
prescribed in CGA C-1 (IBR, see Sec.  171.7 of this subchapter) and 
consistent with the applicable specification testing requirement in 
Part 178 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 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 (IBR, see Sec.  171.7 
of this subchapter). 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 of this subpart. 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 of this subpart. Specification cylinders 
must be in exclusive service as shown in the following table:

------------------------------------------------------------------------
       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,     Butadiene, inhibited, that is
 DOT 4B, DOT 4BA, DOT 4BW.                commercially free from
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B,     Cyclopropane that is
 DOT 4AA480, DOT 4B, DOT 4BA, DOT 4BW.    commercially free from
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B,     Chlorinated hydrocarbons and
 DOT 4BA, DOT 4BW, DOT 4E.                mixtures thereof that are
                                          commercially free from
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 4B,     Fluorinated hydrocarbons and
 DOT 4BA, DOT 4BW, DOT 4E.                mixtures thereof that are
                                          commercially free from
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B,     Liquefied hydrocarbon gas that
 DOT 4B, DOT 4BA, DOT 4BW, DOT 4E.        is commercially free of
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3A480X, DOT 3B,     Liquefied petroleum gas that
 DOT 4B, DOT 4BA, DOT 4BW, DOT 4E.        meets the detail requirements
                                          limits in Table 1 of ASTM
                                          1835, Standard Specification
                                          for Liquefied Petroleum (LP)
                                          Gases or an equivalent
                                          standard containing the same
                                          limits.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT     Methylacetylene-propadiene,
 4BA, DOT 4BW, DOT 4E.                    stabilized, that is
                                          commercially free from
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT     Methylacetylene-propadiene,
 4BA, DOT 4BW, DOT 4E.                    stabilized, that is
                                          commercially free from
                                          corroding components.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT     Propylene that is commercially
 4BA, DOT 4BW, DOT 4E.                    free from corroding
                                          components.
DOT 3A, DOT 3AA, DOT 3B, DOT 4B, DOT     Anhydrous mono,
 4BA, DOT 4BW.                            ditrimethylamines 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).
    (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 (IBR, see Sec.  171.7 of this 
subchapter). A requalification must be performed by the end of 12 years 
after the original test date and at 12-year intervals thereafter.
    (ii) 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.

[[Page 49019]]

    (iii) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (iv) When testing using the water-jacket or direct expansion test 
method, the minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied 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 at a pressure increased by 10 percent or 100 psig, 
whichever is lower.
    (v) The permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure.
    (vi) When testing using the proof pressure test method, the minimum 
test pressure must be maintained for a specific time frame as 
prescribed in CGA C-1. Any internal pressure applied 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 at a pressure increased 
by 10 percent or 100 psig, whichever is lower.
    (vii) When subjected to a proof pressure test, the cylinder must be 
carefully examined under test pressure and removed from service if a 
leak or defect is found.
    (2) 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.
    (ii) The testing procedures, calibration of the testing equipment, 
accuracy of the pressure indicating device, and accuracy of the testing 
equipment must be as prescribed in CGA C-1.
    (iii) Each cylinder must be tested to a minimum of two (2) times 
service pressure.
    (iv) When testing using the water-jacket or direct expansion test 
method, the minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied 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 at a pressure increased by 10 percent or 100 psig, 
whichever is lower.
    (v) The permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure. For DOT 4E cylinders, the 
permanent volumetric expansion may not exceed 12 percent of total 
volumetric expansion at test pressure.
    (vi) When testing using the proof pressure test method, the minimum 
test pressure must be maintained for a specific timeframe as prescribed 
in CGA C-1 (IBR, see Sec.  171.7 of this subchapter). Any internal 
pressure applied 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 at a pressure increased by 10 percent or 100 psig, whichever 
is lower.
    (vii) When subjected to a proof pressure test, the cylinder must be 
carefully examined under test pressure and removed from service if a 
leak or defect is found.
    (3) 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) 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.
    (iii) Each cylinder must be tested to a minimum of \5/3\ times 
service pressure.
    (iv) When testing using the water-jacket or direct expansion test 
method, the minimum test pressure must be maintained at least 30 
seconds and sufficiently longer to ensure complete expansion. Any 
internal pressure applied 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 at a pressure increased by 10 percent or 100 psig, 
whichever is lower.
    (v) The permanent volumetric expansion may not exceed 10 percent of 
total volumetric expansion at test pressure. For DOT 4E cylinders, the 
permanent volumetric expansion may not exceed 12 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
* * * * *
    (m) DOT-3AL cylinders manufactured of 6351-T6 aluminum alloy. In 
addition to the periodic requalification and marking described in Sec.  
180.205 of this subpart, each cylinder manufactured of aluminum alloy 
6351-T6 with a marked service pressure equal to or exceeding 1,800 psi 
must be requalified and inspected for sustained load cracking in 
conformance with the non-destructive examination method described in 
the following table. A cylinder with cracks must be condemned in 
conformance with Sec.  180.205(i) of this subpart.

               Requalification and Inspection of DOT-3AL Cylinders Made of Aluminum Alloy 6351-T6
----------------------------------------------------------------------------------------------------------------
                                                                     Sustained Load Cracking    Requalification
      Requalification requirement        Examination procedure \1\  Condemnation Criteria \2\    period (years)
----------------------------------------------------------------------------------------------------------------
Eddy current examination combined with   Eddy current--In           Any crack in the neck of                   5
 visual inspection.                       conformance with           2 thread lengths or more.
                                          appendix C of this part.
                                         Visual inspection--In
                                          conformance with CGA C-
                                          6.1 (IBR; see Sec.
                                          171.7 of this
                                          subchapter).
----------------------------------------------------------------------------------------------------------------
\1\ The requalifier performing eddy current must be familiar with the eddy current equipment and must
  standardize (calibrate) the system in accordance with the requirements provided in appendix C to this part.
\2\ The eddy current must be applied from the inside of the cylinder's neck to detect any sustained load
  cracking that has expanded into the neck threads.

[[Page 49020]]

    (1) Examination procedure. Each facility performing eddy current 
examination with visual inspection must develop, update, and maintain a 
written examination procedure applicable to the test equipment it uses 
to perform eddy current examinations.
    (2) Visual examinations. Visual examinations of the neck and 
shoulder area of the cylinder must be conducted in conformance with CGA 
C-6.1 (IBR, see Sec.  171.7 of this subchapter).
    (3) Condemnation criteria. A cylinder must be condemned if the eddy 
current examination combined with visual examination reveals any crack 
in the neck of two thread lengths or more, or if visual inspection 
reveals any crack in the neck or shoulder area.
0
48. In Sec.  180.211, revise paragraphs (c) and (e)(1) to read as 
follows:

Sec.  180.211  Repair, rebuilding and reheat treatment of DOT-4 series 
specification cylinders.

* * * * *
    (c) Additional requirements for the repair or recondition of a DOT-
4L cylinder. (1) Repairs to a DOT-4L welded insulated cylinder must be 
performed in conformance with paragraphs (a) and (b) of this section 
with the exception that other welding procedures permitted by CGA C-3 
(IBR, see Sec.  171.7 of this subchapter), and not excluded by the 
definition of ``rebuild,'' are authorized. DOT 4L cylinders must meet 
additional requirements for repair specified in Sec.  180.211(c), 
including being pressure-tested in conformance with the specifications 
under which the cylinder was originally manufactured. DOT 4L cylinders 
that undergo procedures not defined as a repair in Sec.  180.203 are 
not subject to the requirements of Sec.  180.211(c), including the 
requirement to be pressure-tested in conformance with the 
specifications under which the cylinder was originally manufactured.
    (2) After repair, the cylinder must be--
    (i) Pressure tested in accordance with the specifications under 
which the cylinder was originally manufactured;
    (ii) Leak tested before and after assembly of the insulation jacket 
using a mass spectrometer detection system; and
    (iii) Tested for heat conductivity requirements.
    (3) Reconditioning of a DOT 4L welded insulated cylinder must be 
performed in accordance with paragraphs (a) and (b) of this section. 
Reconditioning applies to the work other than repair as described in 
paragraphs (c)(1) and (c)(2) of this section and that work is performed 
on parts other than the inner containment vessel (cylinder). Work to 
recondition a DOT 4L welded insulated cylinder includes the following:
    (i) The removal of either end of the insulation jacket.
    (ii) The replacement of the neck tube. At least a 13 mm (0.51 inch) 
piece of the original neck tube must be protruding above the cylinder's 
top end. The original weld attaching the neck tube to the cylinder must 
be sound, and the replacement neck tube must be welded to this 
remaining piece of the original neck tube.
    (iii) The replacement of material such as, but not limited to, the 
insulating material and the piping system within the insulation space 
with materials that are identical to those used in the original 
manufacture of the cylinder.
    (4) After reconditioning as described in paragraph (c)(3) of this 
section, the welded cylinder must be:
    (i) Pneumatically leak tested, to the closure point of all piping 
and gauging systems, to 90% of the service pressure or the relief valve 
set point, whichever is less;
    (ii) Leak tested before and after assembly of the insulation jacket 
using a mass spectrometer detection system; and
    (iii) Tested for heat conductivity requirements.
* * * * *
    (e) * * *
    (1) The rebuilding of a DOT 4L welded insulated cylinder must be 
performed in conformance with paragraph (d) of this section. DOT-4 
series cylinders requiring rebuild (e.g., when the inner vessel is 
compromised), as defined in Sec.  180.203, must do so in conformance 
with Sec.  180.211. DOT 4L cylinders which undergo procedures that are 
not defined as a rebuild in Sec.  180.203 are not subject to the 
requirements of Sec.  180.203(e). Rebuilding of a DOT-4L welded 
insulated cylinder also includes:
    (i) Substituting or adding material in the insulation space not 
identical to that used in the original manufacture of that cylinder, or
    (ii) Making a weld repair not to exceed 150 mm (5.9 inches) in 
length on the longitudinal seam of the cylinder or 300 mm (11.8 inches) 
in length on a circumferential weld joint of the cylinder.
* * * * *
0
49. 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 of this subpart.
    (iii) The cylinder must be marked in accordance with Sec.  
180.213(f)(10) of this subpart to indicate compliance with this 
paragraph (a)(3).
* * * * *
0
50. In Sec.  180.213, revise paragraphs (c) and (d)(2), and add 
paragraphs (f)(10), (f)(11), and (g) to read as follows:

Sec.  180.213  Requalification markings.

* * * * *
    (c) Requalification marking method. (1) The depth of 
requalification markings may not be greater than specified in the 
applicable specification. The markings must be made by stamping, 
engraving, scribing or other method that produces a legible, durable 
mark.
    (i) Requalification marks must begin at the top of the space 
provided, immediately to the right of the original manufacture date of 
the cylinder, as space allows. Subsequent retest dates must go 
immediately below the previous date, continuing down in sequential 
order to the bottom of the shoulder or area provided for marking. 
Retest marks must proceed further in columns to the right of the last 
column markings.
    (ii) Except as provided in part 178 of this subchapter, stamping on 
the sidewall is prohibited.
    (2) A cylinder used as a fire extinguisher (Sec.  180.209(j) of 
this subpart) may be marked by using a pressure sensitive label.
    (3) 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.
    (4) 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.

[[Page 49021]]

    (d) * * *
    (2) A cylinder subject to the requirements of Sec.  171.23(a)(4) 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)(4)(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)(4) and 180.209(l) 
of this subchapter, the marking is as illustrated in paragraph (d) of 
this section, except that the ``X'' is replaced with the letters 
``EX''.
    (g) Visual inspection requalification markings. Alternative to the 
marking requirements of paragraph (d) and (f)(5) of this section, each 
cylinder successfully passing a visual inspection only, in accordance 
with Sec.  180.209(g) of this subpart, may be marked with the visual 
inspection number (e.g., V123456) issued to a person performing visual 
inspections. An example of the manner in which the markings may be 
applied is as follows:

------------------------------------------------------------------------
 
------------------------------------------------------------------------
                      V123                              V123456
                    03 14E                               0314 E
                       654
            0314 E V123456                        V123456 0314E
------------------------------------------------------------------------

Where:

``03'' is the month of requalification (the additional numeral ``0'' 
is optional'')
``V123456'' is the RIN
``14'' is the year of requalification; and
``E'' to indicate visual inspection
0
51. In Sec.  180.215, revise paragraph (b) and (c)(2)(vii), and add 
(c)(3) to read as follows:

Sec.  180.215  Reporting and record retention requirements.

* * * * *
    (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; date 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. Sec.  173.302a(b)(3) and 180.209(b)(1) 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.
    (5) Eddy current examination records. (i) Records of eddy current 
inspection equipment must contain the following information:
    (A) Equipment manufacturer, model number, and serial number.
    (B) Probe description and unique identification (e.g., serial 
number, part number, etc.).
    (C) Specification of each standard reference ring used to perform 
the eddy current examination.
    (ii) Eddy current examination records must contain the following 
information:
    (A) DOT-specification or special permit number of the cylinder; 
manufacturer's name or symbol; owner's name or symbol, if present; 
serial number, and date of manufacture.
    (B) Identification of each standard reference ring used to perform 
the eddy current examination.
    (C) Name of test operator performing the eddy current examination.
    (D) Date of eddy current examination.
    (E) Acceptance/condemnation results (e.g., pass or fail).
    (F) Retester identification number.
    (c) * * *
    (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 3 
percent of the calculated capacity);
* * * * *
    (3) A record of grinding and ultrasonic examination in conformance 
with Sec.  180.212(a)(3) of this subpart 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).
* * * * *
0
52. In appendix C to part 180, the heading and paragraph 1 are revised 
to read as follows:

[[Page 49022]]

APPENDIX C TO PART 180--EDDY CURRENT EQUIPMENT REQUIREMENTS FOR 
INSPECTION OF DOT 3AL CYLINDERS MANUFACTURED OF ALUMINUM ALLOY 6351-T6

    1. Equipment calibration. Each facility performing an eddy 
current examination must develop, update, and maintain a written 
calibration procedure applicable to the test equipment it uses to 
perform eddy current examinations.
* * * * *

    Issued in Washington, DC on July 11, 2016, under authority 
delegated in 49 CFR 1.97.
William Schoonover,
Acting Associate Administrator for Hazardous Materials Safety, Pipeline 
and Hazardous Materials Safety Administration.

[FR Doc. 2016-16689 Filed 7-25-16; 8:45 am]
BILLING CODE 4910-60-P