{"operation":"document","citation":"PI-70-0111","title":"United Gas Pipe Line Company — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1970-12-02","effective_on":null,"summary":"PI-70-0111 response to United Gas Pipe Line Company concerning 192.55.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-0111.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-0111.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-70-0111","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1970/g70-12-02_Heineman_192.55-lmxs.pdf","body":"<<<PAGE 1>>>\n\nPI-70-0111\nDecember 2, 1970\nMr. W. P. Heineman\nUnited Gas Pipe Line Company\nP.O. Box 1407\nShreveport, Louisiana 71102\nDear Mr. Heineman:\nThis is in reply to your three letters of October 12, 1970, requesting interpretations of various sections of 49 CFR, Part\n192.\nIn answer to your question concerning requirements for two-phase systems, the statement made in Houston that the\nmost severe regulation (either gas or liquid) be complied within two-phase systems is still correct.\nYou state that most two-phase systems are designed to transport primarily natural gas. An examination of the “Gas\nEngineers Handbook”, 1966 edition, page 8/11 on two-phase flow indicated that such systems range from gas bubbling\nin a solid stream of liquid to a fog of liquid in a gas stream. Therefore, to state that all two-phase systems follow either\nthe gas or liquid regulation would not be wise.\nYou state that the B31.8 should be followed in the future as it has been the Code used in the past for two-phase flow. In\nthe case of stress levels in other than Class 1 locations, the gas regulations would be more severe than the liquid, but in\nmost instances the regulations would be similar for transmission type or trunkline type pipelines. Therefore, you should\nhave no problem in following the most severe regulation, at least at present, with the knowledge we have on two-phase\npipelines.\nIn answer to your question regarding transportation of pipe a change in the language of Section 192.65 is under\nconsideration to apply only to pipe transported after the effective date of the regulations. We recognize that there is a\nproblem with respect to application of our regulation to the original transportation of existing stock of pipe. Therefore,\nwe suggest that you furnish all available information as to the transportation procedures used before RP5L1 was issued\nand the precise nature and magnitude of the problem.\nWith regard to your letter on the qualification of steel pipe presently in inventory, our recent amendment to Section\n192.55 and Appendix B should have alleviated much, if not all of the problem. If you still find that you have a large\ninventory that does not qualify under a listed specification or Section 192.55 (d), you may wish to petition for a waiver.\nShould you elect to follow this course of action, I suggest that your petition contain the following information:\n1. The magnitude of the problem in terms of quantity of pipe and its value.\n2. The reasons why qualification of the pipe under Section 192.55(a)(2) is not appropriate.\n3. The basis upon which the waiver could be found not inconsistent with pipeline safety.\n4. A indication as to whether other companies might also be adversely affected (if the problem is\nwidespread, an amendment might be more appropriate).\n5. Suggested language for an amendment that would alleviate the problem while assuring and equivalent\nlevel of safety.\nIf we can be of further assistance, please do not hesitate to ask.\nSincerely,\nOriginal signed by:\nJoseph C. Caldwell\nDirector, Acting\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nUnited Gas Pipe Line Company\nP.O. Box 1407\nShreveport, Louisiana 71102\nOctober 12, 1970\nOffice of Pipeline Safety\nDepartment of Transportation\n400 Sixth Street, S.W.\nWashington, D. C. 20590\nRe: Transportation of Natural and Other Gas by Pipeline - Minimum\nSafety Standards\nGentlemen:\nIt has been brought to our attention, as a result of the Office of Pipeline Safety seminar in Houston on October\n6, 1970, that gas offshore pipelines to be operated as two-phase systems would be expected to comply with the most\nsevere of either of the oil pipeline rules or gas pipeline rules. Offshore gas pipeline systems, prior to this date, have\nbeen designed, with respect to stress from internal pressure, on the same basis as inshore pipelines. This neglects, of\ncourse, consideration of laying stresses which are common to both oil or gas lines. It is recognized that a two-phase\nsystem, which is designed primarily to transport natural gas, can and does accumulate liquids; however, the liquids do\nnot create surge problems since a liquid accumulation as it moves down the pipeline is cushioned by the preceding gas.\nExcept for the liquid handling facilities required inshore to remove the liquids from a two-phase system, we do not feel\nthat the operating stress problems are different from those in a dry gas system.\nMost offshore gas systems, except for those close inshore, are two-phase systems. These have been designed to\noperate at stress levels prescribed in the B31.8 Code. We would recommend that the Office of Pipeline Safety consider\nthe continuation of similar design criteria for offshore two-phase systems as has been used in prior years.\nYours very truly,\nW. P. Heineman\n\n<<<PAGE 3>>>\n\nUnited Gas Pipe Line Company\nP.O. Box 1407\nShreveport, Louisiana 71102\nOctober 12, 1970\nOffice of Pipeline Safety\nDepartment of Transportation\n400 Sixth Street, S.W.\nWashington, D. C. 20590\nRe: Transportation of Natural and Other Gas by Pipeline - Minimum\nSafety Standards\nGentlemen:\nThe following is submitted to your office for clarification of Paragraph 192.65, \"Transportation of Pipe\", in the\nabove referenced regulations.\nThis requirement implies that all pipe installed after the effective date of the regulations and with a diameter to\nwall thickness ratio of 70 to 1, or more, that is transported by railroad shall be transported in accordance with API\nRP5L1. United Gas Pipe Line Company currently has an inventory of line pipe in this category which is estimated to be\nvalued at $1.1 million. This pipe was purchased prior to the issuance of API RP5L1. It is common practice for large gas\ntransmission companies to maintain adequate inventories of pipe for maintenance and emergency purposes. This\ninventory can become quite large, especially in a company such as United Gas Pipe Line Company where we have a very\nwide range of diameters, wall thicknesses and grades.\nWe do not believe it was the intent of your office to eliminate the use of new pipe that was shipped prior to the\nissuance of this regulation. We will appreciate your clarification of this rule to accommodate and permit the use of\nthese pipe inventories.\nYours very truly,\nW. P. Heineman\n\n<<<PAGE 4>>>\n\nUnited Gas Pipe Line Company\nP.O. Box 1407\nShreveport, Louisiana 71102\nOctober 12, 1970\nOffice of Pipeline Safety\nDepartment of Transportation\n400 Sixth Street, S.W.\nWashington, D. C. 20590\nRe: Transportation of Natural and Other Gas by Pipeline - Minimum\nSafety Standards\nGentlemen:\nThe following comment is submitted to your office in consideration of problems which could occur with\nreference to Subpart B - Materials.\nParagraph 192.55 indicates that new steel pipe would have to be qualified under a listed specification under\nAppendix B. Most major pipeline companies have large inventories of line pipe for both maintenance and emergency\npurposes. Appendix B would require that, for example, new pipe would have to be manufactured to API 5LX Standard,\ndated 1970. United Gas Pipe Line Company has a current inventory of new pipe of approximately $1.6 million, which is\npipe manufactured to API 5L or API 5LX specifications dated prior to 1970. A strict interpretation of this rule would,\ntherefore, be burdensome to our company.\nWe do not believe that it was the intent of the rules to prohibit the use of new pipe simply because it was\nmanufactured to a specification prior to the current edition. Such a requirement would be expensive and costly to the\ngas industry without any benefit to pipeline safety. We will appreciate your clarification of this requirement such that it\nwill permit the use of pipe in current inventories.\nYours very truly,\nW.P. Heineman","truncated":false,"body_characters":7741}