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PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION UNITED STATES DEPARTMENT OF TRANSPORTATION
WASHINGTON, DC
Docket No. PHMSA-‐2014-‐0098 Notice of Proposed Rulemaking Pipeline Safety: Plastic Pipe Rule
COMMENTS OF THE PLASTICS PIPE INSTITUTE
The Plastics Pipe Institute (PPI) is the leading trade association representing more than 300 members and associates involved in the use of plastic pipe in our nation’s infrastructure including: plastic piping system manufacturers, resin producers, and plastic equipment manufacturers. Many of the members produce plastic pipe, fittings, and components used in our nation’s natural gas distribution network, and for a wide range of oil & gas gathering applications. Today polyethylene and polyamide piping represents more than 95% of all newly installed gas distribution piping, and HDPE, polyamide and advanced composite piping represent a large portion of the oil & gas gathering market in North America.
PPI supports the efforts of PHMSA to update CFR 49 part 192 to reflect more current materials, standards, and practices included in this notice of proposed rulemaking (NPRM). The overall NPRM contains many improvements to pipeline safety which PPI supports. Some areas may require further clarification, and PPI provides suggested language where necessary.
The following comments are submitted on behalf of PPI.
A. Definitions
PPI recommends that PHMSA make the material traceability definition listed in §192.3 consistent with the information included in ASTM F2897-‐11a. ASTM F2897-‐11a includes the following attributes: Manufacturer; lot code; production date; material; component type; and size.
Gas product standards now include reference to ASTM F2897, and manufacturers have developed their production and marking processes to accommodate the specific encoding system (16-‐character code and barcoding) provided in ASTM F2897. Alteration of those traceability requirements would unnecessarily require manufacturers to revamp their existing barcoding and marking systems.
In order to make the definition consistent with the referenced standard PPI recommends the following definition:
Traceability information means data that is provided within ASTM F2897-‐11a (incorporated by reference, see § 192.7) that indicates within the unique identifier: manufacturer; lot code; production date; material; component type; and size.
PPI supports the PHMSA proposal to adopt the definition of “Weak Link” proposed in [§192.3]. Weak links are available for the allowable pull force requirements for PE pipe and tubing. A properly selected break-‐away swivel provides added assurance against damaged pipe and is good engineering practice.
B. Standards Incorporation by Reference
PHMSA is proposing to incorporate by reference ASTM D2513-‐12ae1 into §192.7. PPI supports the IBR of updated ASTM standards, but feels that ASTM D2513-‐14 should be incorporated by reference instead of ASTM D2513-‐12ae1to reflect the most recent requirements for PE gas piping and all applications of the standard including transmission.
PHMSA is proposing to IBR PPI TR-‐3/2012 and TR-‐4/2012 into §192.121. PPI strongly supports the incorporation by reference of PPI TR-‐3 and PPI TR-‐4 into §192.121. PPI TR-‐3 provides the methods to establish long-‐term pressure ratings for plastic pipe. PPI recommends that PHMSA reference the more current version of PPI TR-‐4 (TR-‐4/2014) as it would provide the most updated listings, and provide additional assurance that the gas piping meets the most stringent industry requirements for long-‐term performance.
C. Marking of Materials
PHMSA is proposing to reference ASTM F2897-‐11a in §192.63 and added requirements that appear to establish marking requirements for legibility, visibility, and permanency using specific product standards, but the wording is ambiguous. The intent should be to ensure that product markings are readable by the operator or installer at the time of installation to provide a means for tracking and traceability. Marking permanency should be clearly defined to mean up to the time of installation, or preferably, should be replaced by the term “readable”. PPI recommends revising section 192.63, (e) (3) as follows:
(3) All markings on plastic pipelines prescribed in the specification and paragraph (e)(2) shall be legible, visible, and readable in accordance with the listed specification at the time of installation.
Current marking technology on PE can provide barcode markings capable of withstanding outdoor exposure for up to 3 years due to constraints in ink technology and the fact that PE is a difficult substrate
material to apply print. Due to these printing constraints, it’s necessary to define the maximum storage duration and marking durability. PPI recommends adding the following language:
ASTM F2897 barcode markings shall be able to withstand at least 36 months of outdoor exposure and withstand abrasion associated with normal storage and transportation operations.
PPI supports the efforts of PHMSA to improve the tracking and traceability of gas system components through the reference of ASTM F2897, but recommends an extended implementation timeline to allow manufacturers and operators to better align their traceability systems.
D. Design of Plastic Pipe
PPI strongly supports the requirement proposed in §192.121 (b) (4) that all plastic pipe have a listed HDB in accordance with PPI TR-‐4 as an added assurance of product safety.
PPI also supports the merger of §192.121 and 192.123 and the proposed increased in design factor for PE in §192.121, but questions the rational for the size and maximum pressure limitations imposed in the proposed rule.
There is no justification provided for limiting the maximum design pressure to 125 psig. PE pipelines produced to ASTM D2513 are regularly used in gas gathering applications at pressures above 125 psig and should be allowed to operate at pressures well within their design capabilities. PPI recommends that the maximum design pressure be determined using the design equation in 192.121 with the applicable design factor.
The size limitation of 12 inches appears arbitrary. PE piping larger than 12 inches has been installed for gas distribution by many LDCs. Plastic pipe pressure carrying capability and quality is not based on pipe diameter. ASTM D2513-‐12ae1 provides performance requirements and dimensions for polyethylene up through 24 inches in diameter.
PPI recommends revising section 192.121, (2), (i) and (iii) as follows:
(i) The design pressure is limited to the value calculated in §192.121 (a) design formula. (iii) The pipe has a nominal size (IPS or CTS) of 24 inches or less
This also necessitates the revision of the wall thickness table referenced in 192.121, (2), (iv) to include dimensions up through 24 inches in diameter as shown in Table 1.
Pipe size (INCHES)
Minimum wall thickness (inches)
Corresponding DR (values)
½” CTS 0.090 7 ¾” CTS 0.090 9.7 ½” IPS 0.090 9.3 ¾” IPS 0.095 11 1” IPS 0.120 11 1 ¼” IPS 0.151 11 1 ½” IPS 0.173 11
2” 0.216 11 3” 0.259 13.5 4” 0.265 17 6” 0.315 21 8” 0.411 21 10” 0.512 21 12” 0.607 21 16” 0.762 21 18” 0.857 21 20” 0.952 21 22” 1.048 21 24” 1.143 21
Table 1: Proposed wall thickness and DR’s
E. PA-‐11 and PA-‐12
PPI strongly supports the increased design factor, the corresponding increased design pressure limitation, and increase in allowable diameters up through 6 inches for PA-‐11 piping into §192.121. In addition, PPI supports the incorporation by reference of PA-‐12 piping and related design requirements in §192.121.
F. General Requirements
In the NPRM [§192.143(c)] PHMSA appears to imply that all plastic components will need a listed specification to use them. PHMSA is now referencing ASME B16.40 in §192.7 to satisfy requirements in [§192.145(f)] but ASTM F2138 -‐ Standard Specification for Excess Flow Valves (EFVs) for Natural Gas Service is not listed in §192.7 or included in this NPRM. EFV’s are currently required by code in §192.381 and ”must be manufactured and tested by the manufacturer according to an industry specification, or the manufacturer’s written specification, but not necessarily a listed specification.” If it is PHMSA’s intent to consider EFVs in plastic pipe systems as a “plastic component.” under [§192.143(c)], PPI recommends that PHMSA add ASTM F2138 or some other applicable standard to the list of documents incorporated by reference in §192.7. Alternatively, PPI recommends that PHMSA clarify and confirm its intent to not consider EFVs to be plastic pipe components [§192.7].
G. Risers
The term “riser” can have multiple meanings in a gas system. ASTM F1973 is specific to Factory Assembled anodeless risers. The NPRM [§192.204(b)] states: “risers shall be designed and tested in accordance with ASTM F1973”. This restricts risers to “factory assembled” risers and excludes risers that are “field assembled” and manufactured to ASTM F2509 -‐ Standard Specification for Field-‐assembled Anodeless Riser Kits for Use on Outside Diameter Controlled Polyethylene Gas Distribution Pipe and Tubing. PPI recommends that PHMSA change §192.204(b) to:
(b) Risers shall be designed and tested in accordance with a listed specification.
PPI also recommends that PHMSA add ASTM F2509 to the list of documents incorporated by reference in §192.7
The requirement for a 3 ft. horizontal leg to §192.204 is ambiguous and does not assure adequate support. PPI recommends that PHMSA remove the requirement for a 3 ft. horizontal leg and adopt performance-‐based language similar to what is used for service line risers and include the following language:
(1) The above-‐ground level part of the plastic pipe is protected against deterioration and external damage (2) The plastic pipe is not used to support external loads;
H. Plastic Pipe Joining
PHMSA proposes to require that all mechanical joints fittings be category 1 as defined by the referenced product standards [§192.281]. While PPI supports the change to require that all mechanical joints and fittings be category 1, the maximum commercially available size is currently limited to 8 inches. The proposed rule would eliminate the use of mechanical fittings on plastic pipe larger than 8 inches until such time that a category 1 mechanical fitting could be developed for larger dimensions. PPI recommends the following revision for this section:
(4) All mechanical joints or fittings (8 inches or less) shall be Category 1 as defined by ASTM F1924, ASTM F1948, or ASTM F1973 (incorporated by reference, see § 192.7) for the applicable material, providing a seal plus resistance to a force on the pipe joint equal to or greater than that which will cause no less than 25% elongation of pipe, or the pipe fails outside the joint area if tested in accordance with the applicable standard.
PPI supports the IBR of ASTM F2620-‐12, but asserts that equally sound fusion joining procedures exist that have already been adopted by many gas operators. For example, PPI TR-‐33 and TR-‐41 are proven procedures that have been successfully used in industry for many years. PPI recommends the revising [§192.281] text to read:
(c) Heat-‐fusion joints. Each heat fusion joint on a plastic pipe and/or component must comply with ASTM F2620-‐12 (incorporated by reference in § 192.7) or other existing equivalent procedure(s), and the following:
PPI does not support the limitation in the use of socket fusion to 1¼ inches or less. No justification is provided for limiting the use of socket fusion to 1¼ inches or less. ASTM F2620-‐12 provides guidance on socket fusion up to 4 inch IPS. PPI recommends the following language in [§192.281]:
(2) A socket heat-‐fusion joint equal to or less than 4-‐inches must be joined by a device that heats the mating surfaces of the pipe and/or component, uniformly and simultaneously, to establish the same temperature. The device used must be the same device specified in the operator’s joining procedure for socket fusion. A socket heat fusion joint may not be joined on a pipe and/or component greater than 4 inches
I. Repair of plastic pipelines
PHMSA is proposing to add the requirement to §192.311 that “(b) All scratches or gouges exceeding 10% of wall thickness of pipe and/or components shall be repaired or removed.” PPI supports this proposal as a reasonable and conservative maximum scratch or gouge depth, but recommends that a wider tolerance be allowed. A GRI (2000) study “Service performance of Polyethylene Pipes Containing Surface Notches Subjected to Internal Pressure” demonstrated scratches or gouges in excess of 30% could be tolerated by PE pipes without significant impact to long-‐term performance. Allowing for a visual inspection of the scratch or gouge depth will simplify damage inspection while still providing a safe and conservative approach. Based on the work by GRI and recommendations included in the PPI Handbook of PE Pipe, 2nd ed., PPI recommends the following language for §192.311:
(b) Based on visual inspection, all scratches or gouges exceeding 10% of the wall thickness of pipe and/or components shall be repaired or removed
J. Bends and elbows.
The bend radius requirement added to §192.311 has been misworded. The maximum radius should be stated as a minimum radius. PPI recommends the following revised text:
(d) Plastic pipe may not be installed containing bends that are less than the minimum radius specified by the manufacturer for the diameter of the pipe being installed
K. Installation of Plastic Pipelines
PHMSA is proposing additional backfill requirements to §192.321(i)(2) and §192.386(c)(2). PPI believes that the language proposed by PHMSA in (i)(2) is not clear and may lead to misinterpretation. PPI suggests that
PHMSA rely on engineering design information such as that contained in The PPI Handbook for PE Pipe for construction guidance, Chapter 7 – Underground installation of PE pipe.
PPI appreciates the opportunity to comment on the above-‐referenced Notice of Proposed Rulemaking and looks forward to receiving the requested information, and updates to the final rule.
Should you have any questions regarding these comments or about the PPI in general, please do not hesitate to call me at 763-‐691-‐3312 or [email protected].
Respectfully submitted,
Randall Knapp
Director of Engineering -‐ EPSD
Plastics Pipe Institute