{"operation":"document","citation":"PI-70-0108","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-70-0108 response to Public Service Commission concerning 192.111.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-0108.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-0108.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-0108","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1970/g70-11-03_Hoppe_192.111-msfX.pdf","body":"<<<PAGE 1>>>\n\nPI-70-0108\nNOVEMBER 03, 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 192, 49 CFR as issued on\nAugust 11, 1970. With regard to your first question concerning Section 192.197(c)(4), it is not intended to permit the\nautomatic shut-off device to be located downstream of the service regulator. If this were done, it certainly could cause\na ruptured diaphragm in the service regulator which would be dangerous. What is intended is that the shut-off device\nbe located up stream of the service regulator, but controlled by excessive pressure downstream of the service regulator\nby means of a control line connected from a point downstream of the service regulator.\nSection 192.197(c)(3), in its second sentence states \"The relief valve may either be built into the service regulator or it\nmay be a separate unit installed downstream from the service regulator.\" No mention is made of a shut-off device\ndownstream of the service regulator. There are service regulator diaphragm, and those would meet the requirements\nof this section. In regard to the possibility of exceeding 60 psig or 125 psig, depending upon the design of the system,\nthere are requirements in Sections 192.199 and 192.201 for limiting pressures ar regulator stations supplying\ndistribution systems.\nWe are at present actively considering revision of several sections of Part 192 for clarification. Section 192.197(c)(4) will\nbe added to the list for such consideration.\nWith reference to your second question, Section 192.555 does provide an exception to the usual test requirements of\nSection 192.619 . This exception was provided for in the previous minimum safety standards, the ANSI B31.8 Code\n§845.23(3) and was apparently believed to be an adequate 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 pressure allowed for a\nnew line of the same design in the same location. Section 192.555(d)(2)(ii) is subject to the further requirements of\nSection 192.555(d)(2)(i), which states that a test must be impractical. Section 192.555(d)(2)(iii) places the burden on the\noperator to determine that the new MAOP is consistent with the condition of the segment of pipeline and the design\nrequirements. A new line in a Class 1 location may not be designed for operation at more than 72% of SMYS, (Section\n192.111). Combining the limitations of those two sections leads to the conclusion that a line uprated under the\nprovisions of Section 192.555(d) could only be operated at 57.6% of specified minimum yield strength.\nSince you have raised the question of the safety of such a procedure the question will be considered for future\nrulemaking procedures.\nSincerely,\n/signed/\nJoseph C. Caldwell\nDirector, Acting\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nState of Michigan\nDepartment of Commerce\nSeven Story state Office Bldg.\nLansing, Michigan 48913\nOctober 14, 1970\nOffice of Pipeline Safety\nDepartment of Transportation\n400 Sixth Street, S.W.\nWashington, D.C. 20590\nGentlemen:\nThe review of Part 192 in Title 40, Code of Federal Regulations, by the Commission staff, has raised a number of\nquestions in our minds regarding the meaning and intent of certain sections. We hope to be able to resolve most of\nthese questions at the meeting in Kansas City, but we wish to direct your attention to two particular areas that we feel\ninvolve more than meaning and intent.\n1. Section 192.197 (c) (4)\nThis subsection does not appear to be compatible with subsection (c) (3). If the automatic shutoff device is\nlocated upstream of the service regulator, the pressure on the upstream side of the regulator could exceed 125 psig as\nlong as the regulator maintained a pre-set downstream pressure. If the automatic shutoff device is located downstream\nof the service regulator, high pressure (60 +. psig) would be imposed on the downstream side of the regulator whenever\nthe automatic shutoff device closed. Many service regulators are not qualified for imposition of high pressure on the low\npressure side of the regulator.\n2. Section 192.555 (d) (2) (i) & (ii)\nThis subsection seems to negate the intent of Section 192.619 (a) (3) and (c). It could allow for upgrading the\nMAOP of a pipeline to a higher pressure than would be allowed by 192.619 (a)(3) and (c) even though the line had not\nbeen tested in the preceding 10-30 years and had never been operated at the proposed new MAOP.\nAccordingly, it appears to us the present provisions of the above- mentioned subsections should be revised to\ncover the points we have brought up.\nYours very truly,\nF.M. Hoppe\nDirector of Public Utilities","truncated":false,"body_characters":4842}