{"operation":"document","citation":"PI-75-038","title":"Tennessee Public Service Commission — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1975-07-28","effective_on":null,"summary":"PI-75-038 response to Tennessee Public Service Commission concerning 192.619.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-75-038.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-75-038.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-75-038","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1975/PI75038.pdf","body":"<<<PAGE 1>>>\n\nJuly 28, 1975\nMr. John Searcy\nEngineering Division\nTennessee Public Service Commission\nCordell Hull Building\nNashville, Tennessee 37219\nDear Mr. Searcy:\nThe following is in response to your numbered inquiries of July 1, 1975:\n1. Yes.\n2. Yes, Section 192.619(c) applies subject to the requirements of Section 192.621.\n3. For a steel or plastic high-pressure distribution system, the maximum allowable operating\npressure is governed by Section 192.619, subject to the applicable limitation of Section\n192.621. Under these requirements, a person may not operate a pipeline at a pressure\npermitted by Section 192.619(c) if that pressure would exceed the applicable limitation of\nSection 192.621.\nSincerely,\nCesar DeLeon\nActing Director\nOffice of Pipeline Safety\nOperations\ndal\\192\\619\\75-07-28\n1\n\n<<<PAGE 2>>>\n\nJuly 1, 1975\nMr. Joseph Caldwell, Director\nOffice of Pipeline Safety\nDepartment of Transportation\n2100 2nd Street, SW\nWashington, D.C. 20590\nDear Mr. Caldwell:\n1. 2. 3. Is it correct that 192.619(b) and 192.621(b) apply only when 192.619(a)(6) and\n192.621(a)(5) respectively are the applicable criteria for determining maximum allowable\noperating pressure; and that when a maximum allowable operating pressure has been\ndetermined in accordance with 192.619(a)(6) or 192.621(a)(5), that 192.619(b) or\n192.621(b) respectively require over-pressure protection devices to prevent that maximum\nallowable operating pressure from being exceeded?\n192.619(c), under certain conditions, allows an operator to disregard the other provisions\nof 192.619 in determining a maximum allowable operating pressure in steel and plastic\npipelines. 192.619(a)(1) and (a)(6) contain provisions identical to those in 192.621(a)(1)\nand (a)(5) respectively. Is it correct that while 192.619(c) allows these two provisions in\n192.619 to be disregarded, that they cannot be disregarded in 192.621, thereby in effect\ncausing 192.621 to preclude 192.619(c) where these two provisions are concerned?\nIn effect, is it correct that for high pressure steel and plastic distribution systems, the\nmaximum allowable operating pressure is the lowest of a combined list of the pressures in\n192.619(a)(1) through (a)(6) and 192.621(a)(1) through (a)(5), except, depending on the\nanswer to Question 2, as provided in 192.619(c)?\nSincerely,\nJohn Searcy\nEngineering Division\ndal\\192\\619\\75-07-28\n2\n\n<<<PAGE 3>>>\n\nQ-3. IH Mr. Searcy asks, in effect, if MAOP for hi-press. distribution system is determined by list\nof items from 192.619(a)(1-6) and 192.621(a)(1-5), except as provided by 192.619(c).\nMr. DeLeon replies that 192.621 limits 192.619 and that 192.619(c) is not applicable if\npressure exceeds that allowed by 192.621.\nUnless 192.619, including provision of 192.619(c), results somehow in a MAOP lower\nthan that established by 192.621, 192.621 will govern hi-press. distr. syst. of steel or\nplastic.\ndal\\192\\619\\75-07-28\n3\n\n<<<PAGE 4>>>\n\nRE: Interpretation by C. DL. of Searcy letter of 7/1/75\nRemarks:\nQ-1 IH Q-2 IH Mr. Searcy asks if the relief devices must prevent exceeding that particular MAOP\ndetermined by 192.619(a)(6) or 192.621(a)(5). Mr. DeLeon says yes.\nThis is not what 192.619(b) states (§192.???) It states that relf.dev. must prevent the\nMAOP form being exceeded, in accordance with 192.195 which eventually allows the relf.\ndev. to be set per 192.201 (i.e. 10% above MAOP or 1.5 X Op. Pr. as applicable.)\nMr. Searcy asks if 192.619(c) is nullified by 192.621, regarding 192.619(a)(1) & (a)(6)\nMr. DeLeon says yes.\n192.621 would nullify 192.619(c) only for hi-press distribution systems.\ndal\\192\\619\\75-07-28\n4","truncated":false,"body_characters":3613}