# Pipeline Safety Interpretation PI-79-0101 **Citation:** PI-79-0101 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 1979-02-23 PI-79-0101 concerning 192.619. ## Document text <<>> PI-79-0101 Arizona Corporation Commission 2222 West Encanto Blvd. Phoenix, Arizona 85009 February 23, 1979 Mr. Howard Hersey Arizona Public Service Company P.O. Box 21666 Phoenix, AZ 85036 Dear Mr. Hersey: In regards to my interpretation regarding over pressure protection requirements and grandfathering, clarification has been received from DOT, Washington. My interpretation has been substantialized. Please see the enclosed copy of the letter from Cesar DeLeon dated February 14, 1979. As a result of this clarification, please review all pressure regulating stations in Arizona Public Service's systems and make the corrections necessary to comply with over pressure protection requirements as soon as possible. Please acknowledge receipt of this letter and inform this commission of your proposed program schedule for accomplishment of the review mentioned above and correction of deficiencies found resulting from review and this clarification. Sincerely, ARIZONA CORPORATION COMMISSION H. R. Garabrant, P.E. Utilities Safety Engineer Utilities Division <<>> Arizona Corporation Commission 2222 West Encanto Blvd. Phoenix, Arizona 85009 February 23, 1979 TO: All Gas Operators - State of Arizona FROM: H.R. Garabrant, P.E. SUBJECT: Over pressure protection As you are all aware, this commission has been enforcing the over pressure protection requirements when required, regardless of age of the installation, i.e. grandfathering of 192.195 is not applicable as parts 192.619(b) and 192.621(b) are not grandfathered and part 192.195 is incorporated by reference in 192.619(b) and 192.621(b). One company disagreed with our enforcement policy and it was necessary to obtain clarification from Washington to substantiate this position. Substantiation of the interpretation has been received and a copy of the letter stating the facts is enclosed, as it may be of interest to you. Sincerely, ARIZONA CORPORATION COMMISSION H. R. Garabrant, P.E. Gas Utilities Safety Engineer Utilities Division <<>> Department of Transportation Research and Special Programs Administration Washington, D.C. 20590 February 14, 1979 H. R. Garabrant, P.E. Gas Utilities Safety Engineer Utilities Division Arizona Corporation Commission 2222 West Encanto Boulevard Phoenix, Arizona 85009 Dear Mr. Garabrant: This responds to your letter of October 20, 1978, regarding the applicability of sections 192.619(b) and 192.621(b). Your letter notes that sections 192.619(b) and 192.621(b) are operation requirements which are not "grandfathered" and are continuing regulations that are applicable to all pipelines. Your letter mentions that both of these sections reference section 192.195 which states, in part, that " . . . must have pressure relieving or pressure limiting devices that meet the requirements of sections 192.199 and 192.201." As you noted, sections 192.195, 192.199, and 192.201 are design requirements which only apply to pipelines readied for service after March 12, 1971, or replaced, relocated, or otherwise changed after November 12, 1970. You inquire if you are correct in interpreting that all district regulators including those readied for service before March 12, 1971, must meet the requirements of section 192.621(b). Because section 192.195 is incorporated by reference in sections 192.619(b) and 192.621(b), which are operating requirements, the provisions of section 192.195 apply to those pipelines readied for service before March 21, 1971, if section 192.619(b) or section 192.621(b) applies to the pipelines concerned. We trust that this adequately responds to your inquiry. Sincerely, Cesar De Leon Associate Director for Pipeline Safety Regulation Materials Transportation Bureau <<>> UNITED STATES GOVERNMENT DEPARTMENT OF TRANSPORTATION RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION Memorandum DATE: December 19, 1978 Subject: Request for Interpretation From: Chief, Western Regional Office To: Associate Director, Office of Operations and Enforcement Attached is a copy of Mr. Garabrant's letter to you requesting an interpretation. This is the letter we discussed that was sent by you to OPSR for interpretation and was misplaced. Please resubmit to OPSR for immediate action as Mr. Garabrant is anxious to receive the interpretation. Thank you. Jack Overly <<>> Arizona Corporation Commission 2222 WEST ENCANTO BLVD. PHOENIX. ARIZONA SSOOS October 20, 1978 Mr. Robert L. Paullin Associate Director for Operations and Enforcement Materials Transportation Bureau Department of Transportation Washington, D.C. 20590 Dear Mr. Paullin: In the past one area of enforcement that I have given a rather high priority to in this state and one that all companies have been making corrections to comply with has been 192.621(b). "No person may operate a segment of pipeline to which paragraph (a)(5) of this section applies, unless over pressure protection devices are installed on the segment in a manner that will prevent the maximum allowable operating pressure from being exceeded in accordance with section 192.195." Paragraph (a)(5) states. "The pressure determined by the operator to be the maximum safe pressure after considering the history of the segment, particularly known corrosion and the actual operating pressures." The above statements are basically repeated in paragraph 192.619 (b). You will note that section #192.621 and 192.619 are in the regulations under sub-part L. - operations. Interpretations are that this sub-part and sections are applicable to all pipelines regardless of age i.e. not grandfathered (see attached chart). Part 192.619 (b) and 192.621 (b) both refer to 192.195. Part of the requirements of 192.195 include, "-----must have pressure relieving or pressure limiting devices that meet the requirements of sections 192.199 and 192.201." I will not repeat 192.199 here but in paragraph (g) of 192.199 there is a clause "be designed and installed to prevent any single incident such as an explosion in a vault or damage by a vehicle from affecting the operation of both the over pressure protective device and the district regulator. " 192.201 (b) reads "When more than one pressure regulating or compressor station feeds into a pipeline, relief valves or other protective devices must be installed at each station to insure that the complete failure of the largest capacity regulator or compressor or any single run of lesser capacity regulators or compressors in that station will not impose pressure on any part of the pipeline or distribution system in excess of those for which it was designated or against which it was protected, whichever is lower." You will note that sections 192.195 192.199 and 192.201 are in sub-part D - This section is grandfathered and it might be possible to interpret that old regulator stations need not be up dated to include over pressure protective devices at each station. My interpretation has been and I still consider it a defficiency if each district regulator station does not have an over pressure protective device and that a device must be added. This is based on the paragraph 192.621 (b), and is the more stringent condition due to "no person may operate-----.” <<>> One major company is faced with a fairly major effort to correct a considerable number of stations. They have stated that they believe that the regulations exceed the authority given by Congress and that there was no intent by Congress for an operations requirement to require rebuild or adding to existing facilities as Congress "grandfathered" design and construction. I might mention that most of this company's stations feed into various integrated systems and in most cases there is a relief valve some where in the system. I suggested a while back that they use the waiver procedure showing the calculations to prove (under minimum load conditions) that the MAOP would not be exceeded by the allowable amount if any one of the district regulator stations should fail. Such situations would have to be well documented before I would consider a waiver approval. I doubt that this would solve many of their problems as there is a certain amount of pressure gradient involved and a remote relief valve would have to be set lower than normal to prevent over pressuring lines close to the failing regulator station. Before I bring the situation to the attention of the Arizona Corporation Commissioners for show cause action possibly involving fines. I need confirmation from your office that my interpretation is correct and that the Legal Department in Washington confirms that the requirements of 192.621 (b) is in compliance with Congressional intent. I would appreciate a reply as soon as possible on this. NOTE: To put things in the proper perspective, I have not been citing companies where the paragraph 192.199 (g) is in violation as long as 192.201 (b) was in compliance and the equipment installation grandfathered due to age. This is what I think the rules and Congress intended. I don't see that the requirement of adding a relief valve or monitor regulator is any more out of line than adding cathodic protection requirements to older facilities that would otherwise be grandfathered. Sorry to put you to this trouble but I need a certain amount of backup before I present this to the Commission for action. Hopefully, if your answer confirms my interpretation, the company may accelerate their program in this regard and formal Commission action with the usual public hearings avoided. Sincerely, ARIZONA CORPORATION COMMISSION H. R. Garabrant, P.E. Gas Utilities Safety Engineer Utilities Division ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `2f9bdbee839c656990da7e9e35a6205a38a808b905ebbd607e44adb5b292687e` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T23:14:31.037Z - Document slug: `phmsa-interpretation-pi-79-0101` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "pipeline_safety", "representation": "full_text_from_official_pdf", "companies": [], "individuals": [], "refIds": [ "PI-79-0101" ], "catalogDates": [ "1979-02-23" ], "catalogParts": [ 192 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/46766" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "192.619", "192.619(b)", "192.195", "192.621(b)", "192.199", "192.201" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/192619" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1979/g79-02-23_Hersey_192.619-msfX.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1979/g79-02-23_Hersey_192.619-msfX.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1979/g79-02-23_Hersey_192.619-msfX.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/pi-79-0101.pdf", "pdfArtifactSha256": "580c9e944b2798cecf75107b986fefd85181e069908218214556c35494c53b82", "extractedTextPath": "data/sources/phmsa-interpretations/pi-79-0101.v2.txt", "extractedTextSha256": "82b3772a995a662aac76c12452cb4294260190d9441b14c6abf59d590a5f0e44", "pageCount": 6, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```