Document ID: PHMSA-2005-21305-0038
Agency: phmsa
Document Type: Rule
Title: Pipeline Safety: Polyamide-11 (PA-11) Plastic Pipe Design Pressures
Posted Date: 2008-12-24T05:00Z

[Federal Register: December 24, 2008 (Volume 73, Number 248)]
[Rules and Regulations]               
[Page 79002-79005]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24de08-24]                         

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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Part 192

[Docket No. PHMSA-2005-21305]
RIN 2137-AE26

 
Pipeline Safety: Polyamide-11 (PA-11) Plastic Pipe Design 
Pressures

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

ACTION: Final rule.

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SUMMARY: This final rule amends the design factor and design pressure 
limits for natural gas pipelines made from new Polyamide-11 (PA-11) 
thermoplastic pipe. Together, these two changes in the regulations 
allow pipeline operators to operate certain pipelines constructed of 
new PA-11 pipe at higher operating pressures than is currently allowed 
for other plastic pipe materials.

DATES: This final rule takes effect January 23, 2009.

FOR FURTHER INFORMATION CONTACT: Richard Sanders at (405) 954-7214, or 
by e-mail at Richard.Sanders@dot.gov.

SUPPLEMENTARY INFORMATION:

Background

    PHMSA published a Notice of Proposed Rulemaking (NPRM) (73 FR 1307; 
January 8, 2008) proposing to increase the design factor and 
corresponding operating pressure limitations for natural gas pipelines 
made from new Polyamide-11 (PA-11) thermoplastic pipe. PHMSA initiated 
this rulemaking in response to several petitions submitted by Arkema, 
Inc. (Arkema), a manufacturer of PA-11 pipe. In October 2004, Arkema 
submitted two petitions to PHMSA requesting we revise 49 CFR 192.121 
and 192.123. The first petition requested an increase in the design 
factor from 0.32 to 0.40 in the plastic pipe design formula in Sec.  
192.121 for new PA-11 plastic pipe. The second petition requested an 
increase in the design pressure limitation in Sec.  192.123 from 100 
psig (689 kPa) to 200 psig (1379 kPa) for new 2-inch IPS \1\ PA-11 
plastic pipe. The design factor and design pressure limitations for all 
other plastic pipe would remain unchanged.
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    \1\ IPS means Iron Pipe Size, while CTS means copper tube size. 
These are recognized pipe size standards that refer to a nominal 
pipe diameter, not to the actual inside diameter (ID) or outside 
diameter (OD) of a pipe. IPS is generally used for pipe sizes 2 
inches or greater; CTS is generally used for pipe sizes 2 inches or 
less.
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    On June 22, 2005, PHMSA published a notice in the Federal Register 
(70 FR 36093) seeking comments on the Arkema petitions. Following 
public comments and recommendations from PHMSA staff, on April 6, 2006, 
Arkema submitted amended petitions proposing various additional 
requirements and safety controls on the use of PA-11 pipe. Arkema again 
proposed an increase in the design factor in Sec.  192.121 from 0.32 to 
0.40 for new PA-11 pipe, but proposed two new conditions: (1) The 
minimum wall thickness for pipe of a given diameter must be SDR \2\-11 
or thicker; and (2) the rapid crack propagation (RCP) characteristics 
of each new pipe design involving a new diameter or thicker wall must 
be measured using accepted industry standard test methods.
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    \2\ SDR (standard dimension ratio) means the ratio of a pipe's 
average specified outside diameter to the minimum specified wall 
thickness of the pipe. For any given pipe diameter, the higher the 
SDR, the thinner the pipe wall. Typical SDRs are specified in 
industry standards developed by the American National Standards 
Institute (ANSI).
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    Likewise, Arkema proposed that we amend Sec.  192.123 to allow the 
use of PA-11 pipe at a maximum design pressure of up to 200 psig (1379 
kPa) for SDR-11 pipe, but broadened its request to include pipe at 
diameters of up to 4-inch IPS. This request was based on the 
availability of complete PA-11 piping systems; results from a three-
year research program by the Gas Technology Institute; and the 
successful testing of exhumed samples of PA-11 pipe that had been 
installed and operated under Federal and State waivers. Finally, Arkema 
supported a commenter's recommendation to reduce the risk of 
excavation-related damage by requiring that PA-11 pipe be buried with 
warning tapes or other devices designed to alert excavators to the 
presence of a high pressure gas line.
    PHMSA is adopting the amendments as proposed in the NPRM with four 
exceptions:
    (1) We are adding the term ``copper tubing size (CTS)'' to clarify 
that pipeline operators may use copper tube size pipe as well as iron 
pipe size pipe.
    (2) We are adding the term ``thicker pipe wall'' to clarify that 
``SDR-11 or greater'' means pipe with thicker pipe wall.
    (3) We are clarifying that the use of arithmetic interpolation to 
determine a design pressure rating at a specified temperature (i.e., 
``S'' in the plastic pipe design formula in Sec.  192.121) will not be 
allowed for PA-11 pipe. Arkema did not request that we permit such an

[[Page 79003]]

interpolation for PA-11, and nothing in the record would support it.
    (4) Finally, for reasons set forth in the following sections, we 
are not requiring that pipe with design pressures above 100 psig (689 
kPa) be buried with a warning tape or other device designed to warn an 
excavator of the presence of a high pressure gas line.
    This final rule amends our existing plastic pipe design formula in 
Sec.  192.121 to cover pipelines made from new 4-inch IPS (or CTS) or 
less, SDR-11 or greater (i.e., thicker pipe wall) PA-11 pipe with a 
design factor of up to 0.40 and increases the design pressure 
limitation in Sec.  192.123 to 200 psig (1379 kPa) for these same 
pipelines. The design factor for all other plastic pipes remains as 
prescribed in the existing regulations. These rule changes are 
effective January 23, 2009.

Disposition of Public Comments

    On June 22, 2005, PHMSA published a notice in the Federal Register 
(70 FR 36093) seeking comments on the Arkema petitions. We received 
comments from two operators of PA-11 trial systems, one local gas 
distribution company, the Gas Piping Technology Committee, the American 
Gas Association (AGA), the Illinois Commerce Commission, two plastic 
pipe fitting manufacturers and a plastics pipe consultant. These 
comments are discussed in full in the NPRM for this rule published in 
the Federal Register on January 8, 2008.
    PHMSA received 13 sets of comments on the NPRM from 10 commenters, 
including industry trade groups, natural gas distribution utility 
companies, plastic pipe consultants, and the original petitioner. Of 
the 10 commenters, all but one expressed support for the proposed 
increases in design pressure limit and design factor. Of the nine 
commenters in support of the proposed amendments, four supported 
increases in the design factor and design pressure limit but opposed 
the proposed amendment to Sec.  192.123(f)(4) regarding the mandatory 
burial of a warning tape. The single commenter opposed to all of the 
proposed amendments sent two separate comments, one of which does not 
pertain to the rulemaking in question.
    The supporting comments cited laboratory tests results from the Gas 
Research Institute (formerly the Gas Technology Institute) and 
performance during field tests under waivers as evidence that PA-11 
pipe can be operated at the proposed limits without compromising public 
safety. Two of the supporting commenters noted they were currently 
operating PA-11 pipelines under waivers. Supporting commenters also 
cited cost advantages, including efficiencies in installation and 
maintenance, in using PA-11 material rather than metal for gas 
distribution pipelines.
    Four commenters that otherwise supported the proposed changes in 
design factor and design pressure limits objected to the proposal to 
require buried warning tapes or other devices. In general, opposing 
comments characterized the requirements as unnecessary, impractical, or 
overly burdensome. Commenters cited the technical difficulty of burying 
the warning tape and expressed concern that confusion over the rule's 
application could undermine the effectiveness of any new warning. These 
commenters contended that the amendment would cause confusion because 
the regulation would apply to PA-11 pipe operating above 100 psig (689 
kPa) but not to other plastic and metallic pipe operating above 100 
psig (689 kPa)s. Others urged the strengthening of existing 
requirements for damage prevention programs and excavator awareness 
training as a better alternative for reducing excavation-related risk. 
One commenter also suggested the proposed warning tape requirement 
would be better included in Sec.  192.321(e) ``Installation of Plastic 
Pipe,'' and that it should not apply to a pipeline installed within a 
casing or a sleeve. Because we are not adopting the proposed 
requirement in any form, we need not consider whether the operative 
text would better fit in a different section of the regulations. One 
commenter, Sempra Energy Utilities (Sempra), representing Southern 
California Gas Company and San Diego Gas and Electric, opposed all of 
the proposed amendments. Sempura cited four reasons for its opposition, 
as follows:
    1. Discrepancies between Resin Formulations, Hydrostatic Design 
Basis (HDB) and Field Performance Data.
    During the field trials Arkema discovered its new formula for the 
PA-11 pipe, which was designed to reduce heavy metals in its products 
and waste streams, caused an unexpected oxidation problem. Once Arkema 
identified the cause of the problem, it eliminated the problematic 
element, moving the formula closer to an earlier one with a proven 
track record. Arkema also performed analyses and studies, including 
tests of the Nicor Gas pipeline operated under a waiver, to determine 
if the same ``accelerated degradation mechanism'' was at work in the 
newest formula and determined it was not.
    Sempra argued this new information should require additional 
testing to establish the HDB of the material. Arkema responded that it 
received the PPI TR4 HDB [Plastics Pipe Institute, Technical Report, 
TR-4, Recommended Hydrostatic Strengths and Design Stresses for 
Thermoplastic Pipe and Fittings Compounds] listing after due 
consideration of the data by the Hydrostatic Stress Board and that this 
data included HDB equivalency testing at an independent International 
Organization for Standardization certified laboratory. Two respected 
plastic pipe consultants also responded that HDB testing is not 
intended to find issues such as the oxidation problem and that changes 
to the pigment formulation have no effect on the HDB as determined by 
ASTM D2837 [ASTM International Standard D2837, Test Method for 
Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or 
Pressure Design Basis for Thermoplastic Pipe Products.] PHMSA is 
satisfied that Arkema has resolved the oxidation problem and that the 
HDB of the PA-11 material has been properly established.
    2. Advanced Approach for Determining Design Factor for Plastic 
Materials.
    Sempra stated that there is research underway to develop a 
technically sound approach to increase the design factor from 0.32 to 
0.40 for PE [polyethylene] pipes without adversely compromising system 
integrity and overall safety. Sempra stated that a material must 
demonstrate an ample balance between its long-term strength and long-
term in-service stresses acting on the piping system Sempra added that 
testing must be performed to simulate additional stresses acting on the 
pipe (such as point loads, excessive bending strain, compaction, earth 
loading, etc.) to validate safe operations at increased pressures and 
that no test or field trial data has been provided to demonstrate that 
this is true for PA-11. Arkema responded that combined loading tests 
are not relevant to PA-11 because extensive laboratory testing intended 
to identify slow crack growth (SCG) has shown that PA-11 is highly 
resistant to SCG. Arkema added that SCG has never been observed in PA-
11. A respected plastic pipe consultant also responded that the testing 
suggested by Sempra is appropriate for PE material but not for PA-11 
materials because PA-11 does not fail by SCG. Based on the extensive 
laboratory research, field research and the field trial experience, and 
the opinions of plastic pipe experts, PHMSA accepts that PA-11 is not 
likely to fail due to SCG and that additional

[[Page 79004]]

combined loading testing is not warranted.
    3. Clarification of Regulatory Requirements at Increased Operating 
Pressures.
    Sempra suggested that PHMSA provide additional clarification 
regarding the integrity management (IM) requirements that would apply 
to a PA-11 pipeline at the proposed higher operating pressures and 
stresses. PHMSA does not agree that such a clarification is necessary. 
The IM regulations in 49 CFR part 192, subpart O are not based on the 
type of plastic material. While PHMSA acknowledges that operators of 
PA-11 pipelines must address specific IM requirements, the same can be 
said of PE and other plastic pipelines. We expect pipeline operators to 
consider all relevant risk factors, including pipe materials and 
operating pressures, in developing and implementing their IM plans. 
Among other resources, PHMSA's IM Web site and frequently asked 
questions (FAQ) are available to assist operators in addressing PA-11-
specific IM issues that may arise. We also offer written 
interpretations of the code to help clarify specific issues. In any 
case, Sempra or any other interested person could petition PHMSA for a 
change of the IM regulations in accordance with 49 CFR 190.331, if it 
believes the IM regulations are insufficient to address PA-11 
pipelines. On the current record, no such showing has been offered.
    4. Possible Misapplication of Stresses to HDB Ratio.
    Sempra pointed out an incorrect mathematical correlation in the 
NPRM and believed that it undermined the rational for the rulemaking. 
We acknowledge the error but do not agree that it undermines the 
rationale for this rulemaking. The simplified correlation was not 
offered or relied upon by Arkema. PHMSA did not intend this correlation 
to establish the maximum pressure limitation for plastic pipe as Sempra 
asserts, and our analysis in this rulemaking does not depend on the 
comparison. The final rule is amply supported by the data and analysis 
offered by the petitioner and other commenters and by PHMSA's technical 
review, and is reinforced by the overwhelming support for this rule in 
the plastic pipe industry.

Technical Advisory Committee

    The proposal adopted in this final rule was presented and approved 
by PHMSA's Technical Pipeline Safety Standards Committee (TPSSC) at its 
June 10, 2008 public meeting in Washington, DC. At this meeting, PHMSA 
briefed the TPSSC on the proposed PA-11 rule and explained the 
extensive laboratory and field testing that the manufacturer had 
undertaken. Moreover, PHMSA discussed the NPRM comments, including the 
opposition to the proposed requirement to bury a warning tape. Several 
of the TPSSC members expressed support for the proposed rule without 
the requirement for the warning tape. The committee members expressed 
the same concerns with warning tape as the public commenters, 
particularly with respect to the possible confusion such a requirement 
could cause excavators because the regulation would only apply to PA-11 
pipe operating above 100 psig (689 kPa). After careful consideration, 
the TPSSC voted unanimously to find the NPRM and supporting regulatory 
evaluation, with the elimination of the proposed warning tape 
requirement, technically feasible, reasonable, practicable, and cost-
effective. A transcript of the meeting is available in Docket ID PHMSA-
2005-21305.

Regulatory Analyses and Notices

Executive Order 12866 and DOT Policies and Procedures

    This final rule is not a significant regulatory action under 
section 3(f) of Executive Order 12866 (58 FR 51735) and, therefore, was 
not reviewed by the Office of Management and Budget. The final rule is 
also not significant under the Regulatory Policies and Procedures of 
the Department of Transportation (44 FR 11034).
    Installing PA-11 is not mandated; it is optional. PHMSA believes 
operators may choose to install PA-11 pipe, rather than some other type 
of pipe, only if it is the most cost-effective alternative available. 
Consequently, PHMSA anticipates that the benefits of this final rule 
will equal or exceed its costs. Any gas transmission operators with (or 
installing) pipelines in class 3 or 4 locations could potentially be 
affected by this final rule. Furthermore, all gas distribution 
operators could potentially be affected by this final rule. In total, 
PHMSA estimates that the rule could potentially affect 1,450 gas 
transmission and gas gathering operators and 1,450 gas distribution 
system operators.

Regulatory Flexibility Act

    Under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.), PHMSA 
must consider whether this rulemaking action would have a significant 
economic impact on a substantial number of small entities. PHMSA 
estimates that this final rule could potentially affect as many as 479 
transmission system and gas gathering operators and 1,131 gas 
distribution system operators that qualify as small businesses under 
the criteria established for these industries by the Small Business 
Administration.
    The final rule mandates no action by gas pipeline operators. 
Rather, it provides operators with an option to use PA-11 pipe in 
certain pipeline systems. We expect operators to select among 
authorized pipe materials based on economic, operational, or other 
considerations. Consequently, the economic burden of the final rule on 
these potentially affected gas pipeline operators is expected to be 
minimal. Therefore, based on this information showing that any economic 
impact of this rule on small entities will be minimal, I certify under 
section 605 of the Regulatory Flexibility Act that this regulation will 
not have a significant impact on a substantial number of small 
entities.

Executive Order 13175

    PHMSA has analyzed this final rule according to the principles and 
criteria in Executive Order 13175, ``Consultation and Coordination with 
Indian Tribal Governments.'' Because this final rule will not 
significantly or uniquely affect the communities of the Indian tribal 
governments or impose substantial direct compliance costs, the funding 
and consultation requirements of Executive Order 13175 do not apply.

Paperwork Reduction Act

    This final rule does not impose any new information collection 
requirements.

Unfunded Mandates Reform Act of 1995

    This final rule does not impose unfunded mandates under the 
Unfunded Mandates Reform Act of 1995. It does not result in costs of 
$100 million, adjusted for inflation, or more in any one year 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 proposed rulemaking.

National Environmental Policy Act

    PHMSA has analyzed this final rule for purposes of the National 
Environmental Policy Act (42 U.S.C. 4321 et seq.) and has determined 
the final rule may produce minor beneficial impacts on the quality of 
the human environment due primarily to a potential reduction in 
corrosion-related leaks if PA-11 pipe is used instead of steel pipe. We 
have determined there will be no significant environmental impacts 
associated with this final rule.

[[Page 79005]]

Executive Order 13132

    PHMSA has analyzed this final rule according to Executive Order 
13132 (``Federalism''). The final rule does not have a substantial 
direct effect 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. This final 
rule does not impose substantial direct compliance costs on State and 
local governments. This final rule would not preempt state law for 
intrastate pipelines. Therefore, the consultation and funding 
requirements of Executive Order 13132 do not apply.

Executive Order 13211

    Transporting gas impacts the nation's available energy supply. 
However, this final rule is not a ``significant energy action'' under 
Executive Order 13211. It is not likely to have a significant adverse 
effect on the supply, distribution, or use of energy. Further, the 
Administrator of the Office of Information and Regulatory Affairs has 
not identified this rulemaking as a significant energy action.

List of Subjects in 49 CFR Part 192

    Gas, Natural gas, Pipelines, Pipeline safety.

0
For the reasons provided in the preamble, PHMSA amends 49 CFR Part 192 
as follows:

PART 192--TRANSPORTATION OF NATURAL GAS AND OTHER GAS BY PIPELINE: 
MINIMUM FEDERAL SAFETY STANDARDS

0
1. The authority citation for part 192 continues to read as follows:

    Authority: 49 U.S.C. 5103, 60102, 60104, 60108, 60109, 60110, 
60113, 60116, and 60118; and 49 CFR 1.53.

0
2. Revise Sec.  192.121 to read as follows:

Sec.  192.121  Design of plastic pipe.

    Subject to the limitations of Sec.  192.123, the design pressure 
for plastic pipe is determined by either of the following formulas:
[GRAPHIC] [TIFF OMITTED] TR24DE08.014

Where:

P = Design pressure, gauge, psig (kPa).
S = For thermoplastic pipe, the HDB is determined in accordance with 
the listed specification at a temperature equal to 73F[deg] 
(23C[deg]), 100 [deg]F (38 [deg]C), 120 [deg]F (49 [deg]C), or 140 
[deg]F (60 [deg]C). In the absence of an HDB established at the 
specified temperature, the HDB of a higher temperature may be used 
in determining a design pressure rating at the specified temperature 
by arithmetic interpolation using the procedure in Part D.2 of PPI 
TR-3/2004, HDB/PDB/SDB/MRS Policies (incorporated by reference, see 
Sec.  192.7). For reinforced thermosetting plastic pipe, 11,000 psig 
(75,842 kPa). [Note: Arithmetic interpolation is not allowed for PA-
11 pipe.]
t = Specified wall thickness, inches (mm).
D = Specified outside diameter, inches (mm).
SDR = Standard dimension ratio, the ratio of the average specified 
outside diameter to the minimum specified wall thickness, 
corresponding to a value from a common numbering system that was 
derived from the American National Standards Institute preferred 
number series 10.
D F = 0.32 or
    = 0.40 for nominal pipe size (IPS or CTS) 4-inch or less, SDR-11 
or greater (i.e. thicker pipe wall), PA-11 pipe produced after 
January 23, 2009.

0
Amend Sec.  192.123 by revising paragraph (a) introductory text and 
adding a new paragraph (f) to read as follows:

Sec.  192.123  Design limitations for plastic pipe.

    (a) Except as provided in paragraph (e) and paragraph (f) of this 
section, the design pressure may not exceed a gauge pressure of 100 
psig (689 kPa) for plastic pipe used in:
* * * * *
    (f) The design pressure for polyamide-11 (PA-11) pipe produced 
after January 23, 2009 may exceed a gauge pressure of 100 psig (689 
kPa) provided that:
    (1) The design pressure does not exceed 200 psig (1379 kPa);
    (2) The pipe size is nominal pipe size (IPS or CTS) 4-inch or less; 
and
    (3) The pipe has a standard dimension ratio of SDR-11 or greater 
(i.e., thicker pipe wall).

    Issued in Washington, DC, on December 17, 2008.
Carl T. Johnson,
Administrator.
 [FR Doc. E8-30637 Filed 12-23-08; 8:45 am]

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