{"operation":"document","citation":"PI-74-0114","title":"Delmarva Power and Light Company — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1974-05-08","effective_on":null,"summary":"PI-74-0114 response to Delmarva Power and Light Company concerning 192.3.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-74-0114.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-74-0114.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-74-0114","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1974/g74-05-08_Robbins_192.3_Transmission%20Line-nlmx.pdf","body":"<<<PAGE 1>>>\n\nPI-74-0114\nMay 8, 1974\nMr. Walter G. Robbins\nMr. John H. Samonsky\nMr. Nicholas H. Barchock\nDelmarva Power and Light Company\n800 King Street\nWilmington, DE 19899\nGentlemen:\nThank you for your letter of April 12, 1974, asking questions with respect to the meaning of the\nterm \"transmission line.\"\nFirst, you describe a 12-inch transmission line, operated below 20 percent of SMYS, which feeds\na distribution system through 75 district regulator stations. You ask if a district regulator station\nis a \"distribution center\" and, if so, does transmission exist only to the first regulator station or to\neach of the 75 stations?\nAnswer. In 49 CFR 192.3, the term \"transmission line\" is defined as follows:\n\"'Transmission line' means a pipeline, other than a gathering line, that --\n\"(1) Transports gas from a gathering line or storage facility to a distribution center or\nstorage facility;\n\"(2) Operates at a hoop stress of 20 percent or more of SMYS; or\n\"(3) Transports gas within a storage field.\"\nUnder this definition, one terminus of a transmission line is a \"distribution center.\" This\nterminus marks entry of gas into a distribution system. In the system you describe, we assume\nthe lines downstream from the outlet of each regulator are mains and service lines, which\nconstitute a distribution system. Thus, each regulator stations is a \"distribution center,\" and the\nline connecting the 75 regulator stations is a continuous \"transmission line.\"\nSecondly, you describe an LNG plant which serves as a storage facility. Boil-off from the plant\nenters distribution by an 8-inch which runs 2,500 feet into a main tapped with services. You ask,\nsince gas is transported from a storage facility, is the 8-inch line a \"transmission line\"?\nAnswer. If there are no services on the 8-inch line, since it runs from a \"storage facility\" to a\n\"distribution center\" (connection with a main), it is by definition a \"transmission line.\" On the\nother hand, if the 8-inch line is a common source of supply for more than one service line, then\nby definition it is a \"main\" under section 192.3.192.3 TRANSMIL 1\n\n<<<PAGE 2>>>\n\nFinally, you ask how characterization of the lines affects reporting under 49 CFR Part 191, noting\nthat you only file distribution reports.\nAnswer. Lines which fail within the definition of \"transmission line\" should be reported as such\nunder Part 191. However, 40 CFR 191.13 requires the 8-inch line which conveys gas from the\nLNG storage facility to be reported as a \"transmission line\" regardless of its characterization. In\nfuture reports, please indicate those transmission lines previously reported as distribution lines.\nSincerely,\n/signed/\nJoseph C. Caldwell\nDirector\nOffice of Pipeline Safety\n192.3 TRANSMIL 2\n\n<<<PAGE 3>>>\n\nApril 12, 1974\nOffice of Pipeline Safety\nDepartment of Transportation\nOffice of the Secretary\nWashington, D. C. 20590\nAttention: Joseph C. Caldwell\nSir:\nDelmarva Power and Light Company, a gas distribution company operating in northern\nDelaware approximately 80,000 customers, would like to request a formal interpretation of\ntransmission lines and transmission reporting procedures as related to our company.\nWithin our system we have designated lines as transmission lines. These lines\noperate at 150-175 psi, way below 20 % SMYS, and we have no storage fields. However, we\nhave a LNG plant which is used for peak-shaving. This plant with LNG tank, we feel is a storage\nfacility and therefore lines to the plant should be classified as transmission. To fill the LNG tank\nwe take gas from our 12-inch transmission line and liquify it; during peak periods we vaporize\nthe LNG and put it back in the same line. Our transmission lines in turn feed our high-pressure\ndistribution system (25-45 psi) through 75 district regulator stations. What we would like to\nknow is what constitutes a distribution center? It is a district regulator station? If so does\ntransmission lines exist only up to the first district regulator station or does transmission exist to\nall district regulator stations?\nAnother related question is the LNG plants boil-off. We put the boil-off back into\nthe system in an 8-inch distribution (25-45 Psi) line which runs 2500 feet into main tapped with\nservices and high to low (1/4 to 1/2 psi) pressure regulators. Since this is gas from a storage\nfacility is this line classified as transmission? If so, how far?\nDepending upon the interpretation of which lines are of D.O.T. transmission\nclassification what is the interpretation on reporting procedures? We presently file only the\ndistribution report, however, of all of our transmission may be qualified as D.O.T. transmission\n(which is 96.1 of 1013 miles of main) then by rights shouldn't we file the transmission report?\nHowever, if it is all not transmission on would we still be required to fill out this report?\nEnclosed is a print of our gas service area with our transmission lines, LNG plants,\nand also LPG plants (propane-air) which are peak shaving plants but not storage facilities. Also\nmarked are system feed points.\n192.3 TRANSMIL 3\n\n<<<PAGE 4>>>\n\nAny questions regarding our system may be answered by contacting any of the below.\nWalter G. Robbins 302-429-3375\nJohn H. Samonsky 302-429-3414\nNicholas H. Barchock 302-429-3454\nSincerely,\nGas Distribution Dept.\nDelmarva Power and Light Co.\n192.3 TRANSMIL 4","truncated":false,"body_characters":5347}