{"operation":"document","citation":"PI-70-005","title":"Public Service Commission — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1970-11-03","effective_on":null,"summary":"PI-70-005 response to Public Service Commission concerning 192.111, 192.197, 192.555.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-005.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-005.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-005","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1970/PI70005.pdf","body":"<<<PAGE 1>>>\n\nNovember 3, 1970\nMr. F. M. Hoppe\nDirector of Public Utilities\nPublic Service Commission\nSeven Story State Office Bldg.\nLansing, Michigan 48913\nDear Mr. Hoppe:\nThank you for your letter of October 14, 1970, concerning construction of two Sections of Part\n192, 49 CFR as issued on August 11, 1970. With regard to your first question concerning\nSection 192.197(c)(4), it is not intended to permit the automatic shut-off device to be located\ndownstream of the service regulator. If this were done, it certainly could cause a ruptured\ndiaphragm in the service regulator which would be dangerous. What is intended is that the shut-\noff device be located up stream of the service regulator, but controlled by excessive pressure\ndownstream of the service regulator by means of a control line connected from a point\ndownstream of the service regulator.\nSection 192.197(c)(3), in its second sentence states \"The relief valve may either be built into the\nservice regulator or it may be a separate unit installed downstream from the service regulator.\"\nNo mention is made of a shut-off device downstream of the service regulator. There are service\nregulator diaphragm, and those would meet the requirements of this section. In regard to the\npossibility of exceeding 60 psig or 125 psig, depending upon the design of the system, there are\nrequirements in Sections 192.199 and 192.201 for limiting pressures ar regulator stations\nsupplying distribution systems.\nWe are at present actively considering revision of several sections of Part 192 for clarification.\nSection 192.197(c)(4) will be added to the list for such consideration.\nWith reference to your second question, Section 192.555 does provide an exception to the usual\ntest requirements of Section 192.619 . This exception was provided for in the previous minimum\nsafety standards, the ANSI B31.8 Code §845.23(3) and was apparently believed to be an\nadequate safety requirement by the B31.8 Code Committee.\nThe exception, in Class 1 locations only, provides that a line may be operated at up to 80% of the\npressure allowed for a new line of the same design in the same location. Section 192.555(d)(2)(ii)\nis subject to the further requirements of Section 192.555(d)(2)(i), which states that a test must be\nimpractical. Section 192.555(d)(2)(iii) places the burden on the operator to determine that the\nnew MAOP is consistent with the condition of the segment of pipeline and the design\nDB/dal/192.197\n70-11-03\n1\n\n<<<PAGE 2>>>\n\nrequirements. A new line in a Class 1 location may not be designed for operation at more than\n72% of SMYS, (Section 192.1110. Combining the limitations of those two sections leads to the\nconclusion that a line uprated under the provisions of Section 192.555(d) could only be operated\nat 57.6% of specified minimum yield strength.\nSince you have raised the question of the safety of such a procedure the question will be\nconsidered for future rulemaking procedures.\nSincerely,\n/signed/\nJoseph C. Caldwell\nDirector, Acting\nOffice of Pipeline Safety\nDB/dal/192.197\n70-11-03\n2","truncated":false,"body_characters":3058}