{"operation":"document","citation":"PI-74-0133","title":"Tennessee Public Service Commission — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1974-08-13","effective_on":null,"summary":"PI-74-0133 response to Tennessee Public Service Commission concerning 192.197.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-74-0133.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-74-0133.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-74-0133","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1974/g74-08-13_Searcy_192.197-nlmx.pdf","body":"<<<PAGE 1>>>\n\nPI-74-0133\nAugust 13, 1974\nMr. John Searcy\nTennessee Public Service Commission\nCordell Hull Building\nNashville, TN 37219\nDear Mr. Searcy:\nThank you for your letter of July 26, 1974, asking whether 49 CFR 192.197 (a) provides for protection against\noverpressure due to failure of a regulator.\nSections 192.197(a) and (b) protect against unsafe operation of gas utilization equipment due to overpressuring by a\ndistribution system. Paragraph (a) sets forth criteria for a service regulator to provide this protection. Under paragraph\n(b), where a regulator does not meet that criteria, the operator must install suitable devices to protect against\noverpressure when the regulator fails. The problem of providing protection against overpressure due to failure of a\nregulator which meets the criteria of paragraph (a) is not addressed by the regulation.\nWe trust our response is helpful to you.\nSincerely,\nSIGNED\nEDWARD F. CYGAN\nJoseph C. Caldwell\nDirector\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nTennessee Public Service Commission\nCordell Hull Building\nNashville, Tennessee 37219\nJuly 26, 1974\nMr. Joseph C. Caldwell, Director\nOffice of Pipeline Safety\nDepartment of Transportation\n2100 Second Street, SW\nWashington, D.C. 20590\nDear Mr. Caldwell:\nBoth 192.197(a) and (b) intend the same end result, which is prevention of unsafe appliance pressure. (b) must be\ncomplied with when (a) is not. However, in (a), the conditions under which unsafe appliance pressure must be\nprevented are normal operating conditions, and in (b), the condition is regulator failure.\nThis appears to be inconsistent, since compliance with (a) does not provide for regulator failure, yet is the first of two\nalternatives \"...to prevent a pressure that would cause the unsafe operation of any...gas utilization equipment.\"\nIs it correct that the intent of 192.197(a) is to also provide for regulator failure?\nSincerely,\nJohn Searcy\nEngineering Division","truncated":false,"body_characters":1940}