{"operation":"document","citation":"PI-21-0008","title":"Audubon Field Services — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2021-09-01","effective_on":null,"summary":"PI-21-0008 response to Audubon Field Services concerning 195.11.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-21-0008.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-21-0008.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-21-0008","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/pipeline/interpretations/75846/audubon-field-services-pi-21-0008-08-31-2021-part19511.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety Administration September 1, 2021\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nMr. Bryan Louque\nVice President Pipeline Integrity\nAudubon Field Services\n9920 E. 42nd Street\nTulsa, OK 74146\nDear Mr. Louque:\nIn a letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), dated\nMarch 10, 2021, you requested an interpretation of the 49 Code of Federal Regulation (CFR)\nPart 195. Specifically, you requested an interpretation on the term “nominal diameter” as it\nrelates to the requirements of § 195.11(a).\nYou asked for clarification on the size of pipelines intended for inclusion in § 195.11 and that\nPHMSA consider adding a definition to § 195.3.\nThe nominal pipe size (NPS) is related to the inside diameter in inches, and NPS 12 and smaller\npipe has outside diameter greater than the designated size. Therefore, a 6 inches nominal\ndiameter pipe is a 6 ⅝-inches nominal outside diameter pipe and an 8-inches nominal diameter\npipe is an 8 ⅝-inches nominal outside diameter pipe. However, for NPS 14 and larger, the NPS\nis the same as the nominal outside diameter. That is, a 14-inch nominal diameter pipe is the\nsame as a 14-inch nominal outside diameter pipe. API Specification 5L, Specification for Line\nPipe, 45th Edition incorporated by reference in 49 CFR § 195.3(b)(13) (API 5L) uses “specified\noutside diameter” for the nominal outside diameter of pipe. Sections 195.2 (gathering line) and\n195.11(a) reference terms “nominal diameter” or “nominal outside diameter” for pipe, with both\nreferences being the same nominal outside diameter for pipe that is referenced in API 5L. In\naddition, the Research and Special Programs Administration (RSPA) (the predecessor to\nPHMSA) clarified and addressed this issue in a 1994 final rule.\n1 Also, it should be clear that\noutside diameters are furnished by pipe mills in nominal outside diameters that are not in whole\nnumbers for less than or equal to 12-inches pipe diameters. For example, pipe with an outside\ndiameter of 2 ⅜-inches is used by pipe mills for a nominal outside diameter of 2-inches. Other\nexamples include 8 ⅝-inches instead of 8 inches, and 10 ¾-inches instead of 10-inches.\n1 RSPA published the final rule in the Federal Register on Tuesday, June 28, 1994 [59 FR 33388].\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 do not create legally-enforceable rights or obligations and are provided to\nhelp the public understand how to comply with the regulations.\n\n<<<PAGE 2>>>\n\n2\nTherefore, PHMSA has addressed this issue by regulation as explained by the June 28, 1994,\nfinal rule which added using both 6⅝-inches and 8⅝-inches pipe nominal diameters under the\n§ 195.11(a) requirements as pipe outside diameters.\nIf we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.\nSincerely,\nJohn A. Gale\nDirector, Office of Standards\nand Rulemaking\nThe Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations\n(49 CFR Parts 190-199) in the form of interpretation letters. These letters reflect the agency's current application of the regulations to the\nspecific facts presented by the person requesting the clarification. Interpretations do not create legally-enforceable rights or obligations and\nare provided to help the public understand how to comply with the regulations.\n\n<<<PAGE 3>>>\n\nMarch 10, 2021\nJohn A. Gale\nDirector, Office of Standards and Rulemaking\nOffice of Pipeline Safety (PHP-30)\nPHMSA\nUS Department of Transportation\n1200 New jersey Avenue SE\nWashington, DC 20590-0001\nDear Sir,\nI am writing to request clarification of §195.11(a)(1) which defines the diameter of rural gathering line\npipe to which 195.11 is applicable. Clarification is requested on the use of term ‘nominal diameter’ in\ncombination with the stated range of values associated with pipeline outside diameter (OD) dimensions.\n§195.2 – Definitions does not define the term “nominal diameter”. However, it does include a\ndefinition for a gathering line.\n“Gathering Line – Gathering lines means a pipeline 8 5/8 inch or less nominal outside\ndiameter that transports petroleum from a production facility”\n.\nThis definition clearly refers to the pipeline outside diameter (OD) whereas this is not clearly\nstated in 195.11(a)(1).\n§195.11(a) states that a regulated rural gathering line means an onshore gathering line in a rural\narea that meets all of the following criteria-\n§195.11(a)(1) Has a nominal diameter from 6 5/8 inches (168 mm) to 8 5/8 inches (219.1 mm).\nNominal diameter or nominal pipe size as employed in pipeline standards incorporated by reference\nunder §195.3 (ASTM A53, ASTM A106 and ASTM A333) is a whole number. For example, the nominal\ndiameter or nominal pipe size of a 6-inch pipeline is 6 inches. The 6-inch pipeline nominal diameter is\nless than the 6 5/8 inch requirement and therefore would be excluded by 195.11.\nAn 8-inch pipeline nominal diameter or nominal pipe size is 8 inches, which is greater than 6 5/8 inch\nand less than the 8 5/8 inch requirement and therefore would be included by 195.11. Therefore, we can\nconclude that 195.11 is solely applicable to 8” nominal diameter rural gathering pipelines.\nThere are various technical standards incorporated by PHMSA which include definitions of pipeline\nnominal diameter, outside diameter, etc. However, the terminology is inconsistent, which leads to\nfurther opportunity for interpretation.\n\n<<<PAGE 4>>>\n\nExamples provided below:\nASME/ANSI B31.4-2006, “Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids”,\nOctober 20, 2006, defines nominal pipe size:\nA400.2 – Definitions\nNominal pipe size (NPS): see ASME B36.10M p.1 for definition.\nASME B36.10M - 2004 – “Welded and Seamless Wrought Steel Pipe”:\n2.0 Size\nThe size of all pipe is identified by the nominal pipe size.\nThe manufacture of pipe Nominal Pipe Size (NPS) 1/8 (DN 6) to NPS 12 (DN 300), inclusive, is\nbased on a standardized outside diameter (OD). This OD was originally selected so that pipe\nwith a standard OD and having a wall thickness that was typical of the period would have an\ninside diameter (ID) approximately equal to the nominal size. Although there is no such relation\nbetween the existing standard thickness – OD and nominal size – these nominal sizes and\nstandard ODs continue in use as “standard.”\nThe manufacture of pipe NPS 14 (DN 350) and larger proceeds on the bases of an OD\ncorresponding to the nominal size.\nASME B31.8 – “Gas Transmission and Distribution Piping Systems” November 30, 2007:\n804.223 – NPS (nominal pipe size) is a dimensionless designator of pipe. It indicates a standard\npipe size when followed by the appropriate number (e.g., NPS 1 ½, NPS 12).\n804.224 – Diameter or nominal outside diameter is the as-produced or as-specified outside\ndiameter of the pipe, not to be confused with the dimensionless NPS. For example, NPS 12 pipe\nhas a specified outside diameter of 12.750 inches, NPS 8 has a specified outside diameter of\n8.625 inches, and NPS 24 pipe has a specified outside diameter of 24.000 inches.\nI am requesting that PHMSA provide clarification on the size of pipelines intended for inclusion in 195.11\nand that PHMSA consider adding a definition to 195.3 to eliminate confusion on this matter in the\nfuture.\nRespectfully,\nBryan Louque\nVice-President Pipeline Integrity\nAudubon Field Services","truncated":false,"body_characters":7769}