{"operation":"document","citation":"PI-82-018","title":"Missouri Public Service Commission — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1982-09-16","effective_on":null,"summary":"PI-82-018 response to Missouri Public Service Commission concerning 192.201, 192.743.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-82-018.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-82-018.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-82-018","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1982/PI82018.pdf","body":"<<<PAGE 1>>>\n\nSeptember 16, 1982\nMr. Dale W. Johansen\nAssistant Director, Gas Department\nEngineering Section\nMissouri Public Service Commission\nJefferson City, Missouri 65102\nDear Mr. Johansen:\nThe enclosed pipeline safety interpretation has been issued in response to your recent inquiry\nregarding the relationship between §192.743 and §192.201(a). While your inquiry referred only\nto relief devices installed before Part 192 became effective, the interpretation applies to all relief\ndevices that are subject to §192.743, and provides that §192.201(a) should not be used to\ndetermine the relief capacity needed to comply with §192.743.\nSincerely,\n/signed/\nRichard L. Beam\nAssociate Director for\nPipeline Safety Regulation\nMaterials Transportation Bureau\nEnclosure\nDB/dal/192.743\n82-09-16\n1\n\n<<<PAGE 2>>>\n\nNo. 82-9\nDate: September 16, 1982\nDEPARTMENT OF TRANSPORTATION\nRESEARCH AND SPECIAL PROGRAMS ADMINISTRATION\nMATERIALS TRANSPORTATION BUREAU\nPIPELINE SAFETY REGULATORY INTERPRETATION\nNOTE:A pipeline safety regulatory interpretation applies a particular rule to a\nparticular set of facts and circumstances, and as such, may be relied upon\nonly by those persons tow whom the interpretation is specifically\naddressed.\nSECTION: 192.743\nSUBJECT: Pressure limiting and regulating stations.\nFACTS: None\nQUESTION: Should values for \"desired maximum pressure\" and \"required capacity,\" as used in\n§192.743(a) and (b), respectively, be based upon the criteria for pressure relieving and limiting\nstations set forth in §192.201(a)?\nINTERPRETATION: Under §192.743, paragraph (a) requires that relief devices at pressure\nlimiting and regulating stations be tested annually to assure they have enough capacity to limit\npressure on connected facilities to the \"desired maximum pressure.\" Paragraph (b) provides that\nif testing is not feasible, the \"required capacity\" of the devices must be reviewed, calculated, and\ncompared with their rated or experimentally determined capacity.\nThe \"desired maximum pressure\" of facilities is not defined or specifically\nregulated by Part 192. However, the operating pressure of a pipeline may not\nexceed its maximum allowable operating pressure (§§192.619, 192.623) or any\nlower pressure that might be required as a remedial measure for safety (e.g.,\n§192.485). Thus as long as these limits are not exceeded, the \"desired maximum\npressure\" of facilities is subject to the reduced (due to remedial measures, revision\nof the maximum allowable operating pressure (§192.611), or any other reason) and\ntesting shows there is insufficient relief capacity to limit pressure to the lower\nDB/dal/192.743\n82-09-16\n2\n\n<<<PAGE 3>>>\n\nlevel, new or additional relief capacity would have to be installed as required by\n§192.743(c).\nThe plain language of paragraphs (a), (b), and (c) makes it clear that the purpose\nof §192.743 is to assure that relief devices at pressure limiting and regulating\nstations have sufficient capacity to limit downstream pressure to the \"desired\nmaximum pressure.\" It follows that the term \"required capacity\" in paragraph (b)\nrefers to the capacity of relief devices that is needed to achieve this purpose, and\nnot to a capacity required by §192.201(a).\nSection 192.201(a) prescribes capacities that apply to the design of pressure relief\nand limiting stations. The purpose of this rule is to assure that stations are\ninstalled with sufficient capacity to prevent accidental overpressure in connected\nfacilities, based on specified safe pressure limits known at the time of design. As\noperating conditions change, these limits may exceed the \"desired maximum\npressure\" of the facilities. so that additional capacity would be required to meet\n§192.743. Therefore, the capacity requirements of §192.201(a) should not be\nused to determine the capacity of relief devices needed to meet §192.743.\nRichard L. Beam\nAssociate Director for\nPipeline Safety Regulation\nMaterials Transportation Bureau\nDB/dal/192.743\n82-09-16\n3","truncated":false,"body_characters":3958}