{"operation":"document","citation":"PI-03-0106","title":"Southwest Gas Corporation — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2003-09-12","effective_on":null,"summary":"PI-03-0106 response to Southwest Gas Corporation concerning 192.181.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-03-0106.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-03-0106.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-03-0106","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/2003/g03-09-12_Wunderlin_192.181-lmx.pdf","body":"<<<PAGE 1>>>\n\nPI-03-0106\n09-12-03\nMr. James F. Wunderlin, P.E.\nVice President/Engineering\nSouthwest Gas Corporation\n5241 Spring Mountain Road\nP.O. Box 98510\nLas Vegas, NV 89193-8510\nDear Mr. Wunderlin:\nThis is in response to your August 13, 2003, request for an interpretation of the gas pipeline distribution system\nvalve regulations at 49 CFR 192.181 and 192.747. Section 192.181 addresses spacing of emergency valves, location of\nemergency valves on the inlet piping to a regulator station, and accessibility and operability requirements for all valves\ninstalled on a main for operating or emergency purposes. Section 192.747 requires the operator to perform annual\nchecks and service on these valves to ensure safe operation of the gas system.\nYou request a response to the following questions:\n1) Does § 192.181(c)(l) require an operator to maintain every valve installed on a gas system, even if they are\nnot identified as emergency \"key valves\" for operating or emergency purposes,... as readily accessible in accordance\nwith § 192.747?\nNo. Section § 192.181(c)(l) is in Subpart D, Design of Pipeline Components. It addresses minimum requirements\nfor the design and installation of pipeline components. It does not require an operator to maintain all valves in\naccordance with § 192.747.\nValve maintenance is addressed in § 192.747, Valve Maintenance: Distribution Systems. This section requires\nthat \"[e]ach valve, the use of which may be necessary for the safe operation of a distribution system, must be checked\nand serviced at intervals not exceeding 15 months, but at least once each calendar year.\" In compliance with this\nregulation, Southwest Gas has designated many, but not all, gas distribution system valves as \"key valves.\" ,\n2) Is an operator required to abandon, remove, or render inoperable valves not identified\nas emergency \"key valves.\"\nNo. An operator is not required to \"abandon, remove, or render inoperable valves\" simply because they are not\nidentified as \"key valves.\" The pipeline safety regulations at 49 CFR Part 192 do not address this issue.\nAll valves installed in a gas pipeline system must comply with § 192.53, General, which requires that all\ncomponents installed in a gas system must be structurally sound, chemically compatible with the gas transported, and\nqualified in accordance with the requirements of 49 CFR Part 192, Subpart B, Materials. Valves in gas systems must also\nmeet the requirements of § 192.145, Valves, which requires that each valve be manufactured and tested in accordance\nwith standard API 6D. In addition, an operator must also include all valves in leak inspection programs and corrosion\ncontrol programs.\nIf you have any further questions about the pipeline safety regulations, please contact me at (202) 366-4565.\nSincerely,\nRichard D. Huriaux, P.E.\nManager, Regulations\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nAugust 13, 2003\nMs. Stacey Gerard\nAssociate Administrator of Pipeline Safety, DPS-1\nOffice of Pipeline Safety\n400 7th Street, SW\nWashington, DC 20590\nRE: Request for Formal Interpretation of Title 49 CFR §192.181, Distribution line valves and §192.747, Valve\nMaintenance: Distribution Systems\nDear Ms. Gerard:\nSouthwest Gas Corporation (Southwest) is a natural gas local distribution company serving over 1.4 million customers\nand operates approximately 1,481 miles of transmission and 22,999 miles of distribution pipelines in California, Nevada\nand Arizona. Southwest formally requests an interpretation with respect to 49 CFR Part 192.181, Distribution line valves\nand §192.747, Valve Maintenance: Distribution Systems.\nTitle 49 CFR §192.181(a), Distribution line valves states:\n\"(a) Each high-pressure distribution system must have valves spaced so as to reduce the time to shut down a\nsection of main in an emergency. The valve spacing is determined by the operating pressure, the size of mains,\nand the local physical conditions.\"\nSouthwest installs valves on its gas pipeline systems to facilitate new construction and to perform maintenance\nactivities. During the engineering design and emergency isolation plan annual review process, Southwest evaluates and\nrevises its emergency isolation plan as necessary to maintain its ability to isolate portions of its gas system during\nemergencies. This involves the identification of \"key valves\" based upon the size of mains, operating pressures and\nphysical location, such as, business districts and class location. In addition, Southwest utilizes local physical conditions\nlike natural and man made boundaries (i.e. railroads, bridges, highways, desert washes, etc.) during this process.\nTitle 49 CFR §192.181(b), Distribution line valves states:\n\"(b) Each regulator station controlling the flow or pressure of gas in a distribution system must have a valve\ninstalled on the inlet piping at a distance from the regulator station sufficient to permit the operation of the\nvalve during an emergency that might preclude access to the station.\"\nSouthwest installs and maintains valves on its regulator station inlet piping at a distance from the regulator station\nsufficient to permit the operation of the valve during an emergency that might preclude access to the station.\nSouthwest installs and maintains valves on its regulator station inlet piping at a distance from the regulator station\nsufficient to permit the operation of the valve during an emergency that might preclude access to the station.\nTitle 49 CFR § 192.181 (c)(l), Distribution line valves states:\n\"Each valve on a main installed for operating or emergency purposes must comply with the following:\n(1) The valve must be placed in a readily accessible location so as to facilitate its operation in an emergency.\nSouthwest identifies \"key valves\" to be utilized during an emergency that are installed in accordance with the above\nrequirements and maintains them in accordance with Title 49 CFR § 192.747, Valve Maintenance: Distribution Systems.\nOther valves that are installed on Southwest's gas systems to facilitate new construction and to perform maintenance\nactivities are not considered \"key valves\" and may or may not be maintained in accordance with Title 49 CFR §192.747,\nValve Maintenance: Distribution Systems.\nTitle 49 CFR §192.747, Valve Maintenance: Distribution Systems states:\n\n<<<PAGE 3>>>\n\n\"Each valve, the use of which may be necessary for the safe operation of a distribution system, must be checked\nand serviced at intervals not exceeding 15 months, but at least once each calendar year.\"\nBased upon the information provided, Southwest requests your interpretation of the following questions:\n1. Does Title 49 CFR §192.181(c)(l) require an operator to maintain every valve installed on a gas system, even if they\nare not identified as emergency \"key valves\" for operating or emergency purposes, within its' gas system as readily\naccessible in accordance with §192.747?\n2. Is an operator required to abandon, remove or render inoperable valves not identified as emergency \"key valves?\"\nSouthwest appreciates the assistance of the DOT/OPS in clarifying the intent of the requirements outlined in Title 49 CFR\n§192.181, Distribution line valves and §192.747, Valve Maintenance: Distribution Systems. If you have any questions,\nneed any additional information or would like to discuss Southwest's request for interpretation please contact me.\nSincerely,\nJames F. Wunderlin, P.E. Vice President/Engineering","truncated":false,"body_characters":7423}