{"operation":"document","citation":"PI-77-023","title":"Central Plastics Company — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1977-10-18","effective_on":null,"summary":"PI-77-023 response to Central Plastics Company concerning 192.455.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-023.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-023.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-023","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1977/PI77023.pdf","body":"<<<PAGE 1>>>\n\nOctober 18, 1977\nMr. Bob Pourchot\nProduct Engineer\nCentral Plastics Company\nP.O. Box 762\nShawnee, OK 74801\nDear Mr. Pourchot:\nYour letter to Mr. Paul Cory requests that we review the design of the anodeless service riser\nmanufactured by Central Plastics Company and determine if it violates the requirements of the\nFederal gas pipeline safety regulations, 49 CFR Part 192.\nThe Office of Pipeline Safety Operations (OPSO) does not approve, endorse, or make the\nrequested determination on proprietary items. We can, however, discuss the design and indicate\nthe requirements that would be applicable.\nYou previously supplied Mr. Cory with drawings of the service riser in question that show the\ntransition from plastic to metal pipe occurring belowground. This transition is enclosed in a\nmetallic casing that extends belowground over the plastic pipe and upward over the steel gas pipe\nto a point below the threaded upper end of the service riser. The steel gas pipe and the transition\nfitting are insulated from the casing by a combination of polyethylene tubing and epoxy materials.\nThese plastic materials fill the void between the steel gas carrying pipe and the casing and since\nthe plastic is not carrying gas, it is not subject to the temperature limits of Section 192.123.\nAlso, according to the design provided to OPSO, the steel gas carrying pipe that extends from\nbelowground to the head of the service riser is enclosed in a covering of plastic material which in\nturn is covered by the steel casing. Plastic material fills the void between the casing and carrier\npipes and is intended to insulate the carrier pipe from the casing. If it can be shown under Section\n192.455(b) that the steel gas pipe is in a location where a corrosive environment does not exist,\nthen cathodic protection would not be required.\ndal\\192\\455\\77-10-18\n1\n\n<<<PAGE 2>>>\n\nThank you for your interest in pipeline safety. If you have additional questions, please advise.\nSincerely,\n\\signed\\\nCesar DeLeon\nActing Director\nOffice of Pipeline\nSafety Operations\ndal\\192\\455\\77-10-18\n2\n\n<<<PAGE 3>>>\n\nCENTRAL PLASTICS COMPANY\nSeptember 12, 1977\nD.O.T., Office of Pipeline Safety\nAttn: Paul Cory\nTrans Point Bldg.\n2100 Second Street, S.W.\nWashington, D.C. 20590\nDear Paul,\nWe certainly appreciate your efforts to answer P.G.& E.'s questions concerning our anodeless\nservice riser. We are sorry for the mix-up.\nAs I was not entirely sure that Tom Timen was the engineer at P.G.& E. who originally inquired,\nI feel it necessary to go and talk with them again. In order to prevent any further embarrassment,\nI was hoping you could send me a letter. If you would review our design again and merely say if\nit violates the code or not, we would be most grateful. We would then clear up the matter with\nP.G.& E. and P & F ourselves.\nThanks again for your concern.\nRegards,\n\\signed\\\nBob Pourchot\nProduct Engineer\ndal\\192\\455\\77-10-18\n3\n\n<<<PAGE 4>>>\n\nFebruary 2, 1974\nMr. Richard B. Bender\nRichard B. Bender Corrosion\nAssociates\nP.O. Box 11302\nFort Worth, TX 76110\nDear Mr. Bender:\nIn your letter of January 17, 1974, you asked about corrosion control requirements for steel risers\non plastic service lines.\nSteel risers on plastic services must be coated and cathodically protected as required by Section\n192.455 of Subpart I of the Federal regulations. So as to facilitate cathodic protection, each\nservice riser must be electrically insulated from other house piping such as at the regulator, shut-\noff valve or meter as required by Section 192.467(b). The level of protection must meet one or\nmore of the criteria contained in Section 192.463.\nAlso, the frequency for monitoring the cathodic protection applied to service risers is covered by\nSection 192.465.\nWe trust this clarifies the requirements for corrosion control measures applicable to steel risers on\nplastic services. If you desire any further information, please advise.\nSincerely,\n\\signed\\\nJoseph C. Caldwell\nDirector\nOffice of Pipeline Safety\ndal\\192\\455\\77-10-18\n4","truncated":false,"body_characters":4017}