{"operation":"document","citation":"PI-19-0014","title":"Plastics Pipe Institute — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2020-02-20","effective_on":null,"summary":"PI-19-0014 response to Plastics Pipe Institute concerning 192.121.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-19-0014.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-19-0014.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-19-0014","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/pipeline/interpretations/73486/plastics-pipe-institute-pi-19-0014-02-18-2020-part-192121.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nofTransportation\nPipeline and Hazardous Materials\nSafety Administration\n1200 New Jersey Avenue SE\nWashington DC 20590\nF EB 18 2020.\nDr. Randy Knapp\nDirector of Engineering\nEnergy Piping Systems Division\nPlastics Pipe Institute\n105 Decker Court, Suite 825\nIrving, TX 75062\nDear Dr. Knapp:\nIn your correspondence to the Pipeline and Hazardous Materials Safety Administration (PHMSA)\ndated October 16, 2019, you requested an interpretation of the pipeline safety regulations in 49\nCode of Federal Regulations (CFR) Part 192. Specifically, you requested applicability of the§\n192.121 requirements to Class 1 and Class 2 locations, by posing the following question:\nDo the limitations for pressure and diameter in 49 CFRparts 192.121(b), (c), (c)(2)(i) and\n(c)(2)(iii) (i.e., limits of 125 psig and 12-inch diameter) apply to Polyethylene pipe\ninstalled in Class I or 2 locations?\nA detailed response to this question requires understanding the regulatory history of these\nrequirements. When 49 CFR Part 192 was first promulgated in 1970, the design pressure limit for\nplastic pipe used in distribution systems and Class 3 and 4 locations was set at 100 psig (689 kPa),\nwhich was the design pressure limit in ANSI B31. 8 Standard, Gas Transmission Distribution and\nPiping Systems (35 FR 13257; August 19, 1970). In 2004, the design pressure was raised for\npolyethylene (PE) 2406 and PE 3408 thermoplastic pipe because of new developments in PE\nmaterials and better technology for detecting the rate of crack growth (69 FR 32886; June 14,\n2004). The 2004 fmal rule was based on a petition for rulemaking submitted by the American Gas\nAssociation (AGA) in 1998 and amended in 1999. AGA specifically stated in its petition that this\nincrease in the pressure limitation for thermoplastic pipe used in gas distribution systems was\nclearly supported by the proven performance of modem PE pipe and the successful operation of\npipe at greater than 100 psig (689 kPa) under the authority of waivers granted by state pipeline\nregulators (65 FR 15290; March 22, 2000). Therefore, PHMSA intended for the allowance of a\nmaximum design pressure of 125 psig (862 kPa) for thermoplastic pipe to apply to plastic pipe\nused in distribution systems and Class 3 and 4 locations.\nIn the recent plastic pipe fmal rule, PHMSA amended § 192.121 to allow for certain new and\nreplaced PE pipe to operate with a design factor of 0.40 (previously 0.32), though it is limited to a\nminimum wall thickness of0.090 inches (83 FR 58694; November 20, 2018). PHMSA noted\nduring the rulemaking process that at 0.32, operators may still use the design formula in§ 192.121\nThe Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations (49 CFR\nParts 190-199) in the fonn of interpretation letters. These letters reflect the agency's current application of the regulations to the specific facts\npresented by the person requesting the clarification. Interpretations do not create legally-enforceable rights or obligations and are provided to help\nthe public understand how to comply with the regulations.\n\n<<<PAGE 2>>>\n\n2\nin accordance with the applicable standard. Additionally, PHMSA stated that it was not lowering\nthe minimum wall thickness for 0.40 design factor pipe, as the more conservative wall thickness is\nnecessary to mitigate sidewall fusion and tapping risks, among others, that exist at the higher\ndesign factor (Id.). The application of the 0.40 design factor for plastic pipe used in a specific\nclass location must take into consideration the requirements of§§ 192.12l(b) and (c).\nFurthermore, in the final rule, PHMSA merged the design limitations which were previously\nlocated in§ 192.123 into§ 192.121 (Id.).\nTherefore, based on the rulemaking history of§ 192.121 and previous§ 192.123, PHMSA\nprovides the following response to your question.\nSection 192.121(b)(l) limits the design pressure for plastic pipe to not exceed a gauge pressure of\n100 psig (689 kPa) for pipe used in distribution systems or transmission lines in Class 3 and 4\nlocations. However, the requirements of§ 192.121(b)(2) through (b)(4) apply to all plastic pipe,\nincluding PE pipe in Class 1 and 2 locations.\nFor PE pipe produced after July 14, 2004, but before January 22, 2019, the exception in\n§ 192.121(c)(l) to exceed the 100 psig limit for up to and including 12 inches in diameter, but\nlimited to up to 125 psig, is only applicable to PE pipe subject to the requirements of\n§ 192.121(b)(l) (i.e., plastic pipe and components, including PE pipe, installed in distribution\nsystems or transmission lines in Class 3 or 4 locations). On the other hand, PE pipe produced prior\nto January 22, 2019, in Class 1 and 2 locations and not used in a distribution system does not have\nsize and pressure limitations when using a design factor of 0.32 as specified in§ 192.121(a).\nHowever, the maximums used in practice are limited by the design formula and the limitations\nwithin§ 192.121(a), as well as limitations inherent to hydrostatic design basis, standard dimension\nratio, and the practical limitations of PE pipe.\nLikewise, PE pipe in Class 1 and 2 locations and not used in a distribution system and produced\nafter January 22, 2019, does not have explicit limitations for design pressure and outer diameter\nwhen using a design factor of0.32 as specified in§ 192.121(a). However, the exception in§\n192.121(c)(2) allowing the use of a 0.40 design factor for PE pipe produced after January 22,\n2019, is applicable to all PE pipe, including PE pipe in Class 1 and 2 locations. Therefore,\nlimitations on maximum design pressure and maximum outer diameter for plastic pipes with a\ndesign factor of 0.40 apply to all PHMSA regulated PE pipe produced after January 22, 2019,\nregardless of the PE pipe function or location.\nIfwe can be of further assistance, please contact Tewabe Asebe at 202-366-5523.\nSincerely,\n~-•c:u111e\nDirector, Office of Standards\nand Rulemaking\nThe Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations (49 CFR\nParts 190-199) in the form of interpretation letters. These letters reflect the agency's current application of the regulations to the specific facts\npresented by the person requesting the clarification. Interpretations are not generally applicable, do not create legally-enforceable rights or\nobligations, and are provided to help the specific requestor understand how to comply with the regulations.\n\n<<<PAGE 3>>>\n\nFrom: Gale, John (PHMSA)\nTo: Asebe, Tewabe (PHMSA)\nSubject: FW: PPI Request for Interpretation\nDate: Thursday, October 17, 2019 7:24:01 AM\nAttachments: image002.png\nTA:\nNew interp request. Need to respond to this ASAP>\nJohn\nFrom: Randy Knapp [mailto:rknapp@plasticpipe.org]\nSent: Wednesday, October 16, 2019 4:51 PM\nTo: Gale, John (PHMSA) <john.gale@dot.gov>\nSubject: PPI Request for Interpretation\nMr. John A. Gale\nDirector, Office of Standards and Rulemaking\nOffice of Pipeline Safety\nPipeline and Hazardous Materials Safety Administration\nThe Plastics Pipe Institute (PPI) is the leading trade association representing more than 150\nmembers companies and associates involved in the use of plastic pipe in our nation’s\ninfrastructure. Many of the members produce plastic pipe, composite pipe, fittings, and\ncomponents used in our nation’s natural gas distribution network, and for a wide range of oil\n& gas gathering applications. Today polyethylene (PE) represents the majority of gas\ndistribution pipelines and a large portion of oil & gas gathering market in North America.\nThe majority of PE pipe volume is installed in areas with lower population density (class 1 and\n2). In class 1 and 2 locations more than 60% of the PE pipe being used is larger diameter (8”\n–\n36”), and in many of the class 1 and 2 applications higher pressures (well beyond 125 psig) are\ncommonplace. After more than 50 years of successful use of PE in oil and gas applications and\n12 years of experience with high-performance PE 2708 and PE 4710, PE has proven to be the\nbest material in these challenging environments. High performance PE pipes have operated\nsafely at higher operating pressures in non-regulated applications for years and are equally as\nsafe in class 1 and 2 regulated gas distribution, transmission, and gathering applications. The\nuse of more PE pipe in class 1 and 2 locations will result in the increased long-term\nperformance of the piping system and safer pipelines.\nBased on the above discussion PPI is submitting the following request for interpretation:\nDo the limitations for pressure and diameter in 49 CFR parts 192.121(b), (c), (c)(2)(i) and (c)(2)(iii)\n\n<<<PAGE 4>>>\n\n(i.e., limits of 125 psig and 12 inch diameter) apply to Polyethylene pipe installed in Class 1 or 2\nlocations?\nThank you for your consideration of this request. Please let me know if you have any\nquestions.\nI look forward to your response.\nBest Regards,\nRandy Knapp, Ph.D.\nDirector of Engineering\nPlastics Pipe Institute\nCell: 763-691-3312\n–\nEnergy Piping Systems Div.","truncated":false,"body_characters":9127}