{"operation":"document","citation":"PI-79-020","title":"Memo: Internal — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1979-06-22","effective_on":null,"summary":"PI-79-020 response to Memo: Internal concerning 192.741.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-79-020.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-79-020.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-79-020","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1979/PI79020.pdf","body":"<<<PAGE 1>>>\n\nJune 22, 1979\nSUBJECT: Request for Interpretation\nRegulation: §192.741\nFROM: Chief, Central Region, DMT-14\nTO: Associate Director, Office of Pipeline Safety Regulation, DMT-30\nTHRU: Associate Director, Office of Operations & Enforcement, DMT-10\nAttached is a piping schematic indicating pressure regulation within a gas system. The\nschematic includes the transmission lines from the point of purchase from an interstate\ntransmission line and the mains. I would like to know at what stations telemetering or\nrecording pressure gauges are required in accordance with §192.741(a). The regulation\nstates that \"each distribution system supplied by more than one district pressure regulating\nstation must be equipped with telemetering or recording pressure gauges to indicate the\ngas pressure in the district.\"\nThe distribution system is supplied by an 8-inch diameter transmission line which haws\nbeen looped with a 4-inch transmission line as shown. These lines are operated at 172\npsig and supply gas to regulator stations A and B. All of the regulating equipment\nenclosed by the dashed line is located at station B. All other regulating equipment shown\nis at separate locations within the system. The regulating stations are denoted by letters A\nthrough G.\nThe system consists of sections, or districts, operating at pressures of 60 psig, 25 psig, 15\npsig, 8 psig, and 6 ounces. The maximum allowable operating pressures of these sections\nare the same as the operating pressures, since §192.619(a)(3) has been interpreted to\napply to distribution piping.\nAs indicated by the diagram, the 15 psig segment of the system can be supplied by\nregulator stations C, D, and E. The 8 psig segment of the system can be supplied by\nstations G and F. The 25 psig segment can be supplied by stations A and B. The 6 ounce\nsegment can be supplied by two different regulator settings within station B.\nIt is the intent of §192.741(a) to require telemetering or pressure recording devices only\nwhen the entire distribution system is supplied by more than one regulator stations, or\ndoes it also apply to districts within one distribution system? Is each pressure district\nwithin this system a separate distribution system?\nDB\nC:\\WP51\\INTERPRT\\192\\741\\79-06-22\n1\n\n<<<PAGE 2>>>\n\nThe operating, or set pressures of the regulators within station B are as denoted on the\nschematic. The other regulator stations are operated as follows:\nStation A: Inlet pressure 175 psig. This regulator is set at 10 psig to augment\ngas supply in the 25 psig segment should the pressure in that\narea drop that low during periods of high consumption.\nStation C: Inlet pressure 60 psig. Outlet pressure 15 psig.\nStation D and E: Inlet pressure 25 psig. These two regulators are set to\noperate at 10 psig to augment gas supply to the 15\npsig segment should the pressure in that area drop\nthat low during periods of high consumption.\nStations G and F: Inlet pressure 25 psig. Outlet pressure 8 psig.\nAdditionally, does Part 192 require overpressure protection to be installed at regulator\nstations D, E, F, and G. The facilities were installed in the 1950's and the maximum\nallowable operating pressures have been based on §192.619(a)(3). This question has\narisen because determining the pressure per §192.619(a)(3) is based on operating history,\nas is §192.619(a)(b).\nIf you have any questions in regard to the system or comments which you feel would help\nto clarify this matter, please don't hesitate to call.\nMarshall W. Taylor, II\nEnclosure\nDB\nC:\\WP51\\INTERPRT\\192\\741\\79-06-22\n2\n\n<<<PAGE 3>>>\n\nDIAGRAM\nDB\nC:\\WP51\\INTERPRT\\192\\741\\79-06-22\n3\n\n<<<PAGE 4>>>\n\nC:WPS IUNTERPRT1921741179-06-22","truncated":false,"body_characters":3661}