Public Utilities Commission of Ohio — Pipeline Safety Interpretation

Page 1May 2, 1994 Mr. Edward M. Steele Chief, Gas Pipeline Safety Section The Public Utilities Commission of Ohio 180 E. Broad Street Columbus, OH 43266-0573 Dear Mr. Steele: I am responding to your letter of March 23, 1994, concerning the maximum allowable operating pressure (MAOP) of pipeline in two distribution systems. Answers to your questions regarding each system follow. The first system has an MAOP of 125 psig based on a maximum safe pressure (§§ 192.619(b)(6) and 192.621(a)(5)), but the system was operated at 145 psig during the 5–year period prior to July 1, 1970. Section 192.619(c) would allow a new MAOP of 145 psig if the system is now in “ satisfactory condition,” and the limitations on MAOP under § 192.611 (class location change) and § 192.621 (high-pressure distribution systems) are met. However, any increase in MAOP above 125 psig must comply with the uprating requirements of Subpart K of Part 192 (§ 192.551). Subpart K would still have to be met even if the system has been tested after construction to at least 218 psig (1.5 time 145 psig). The second system has an MAOP of 5 psig based on a maximum safe pressure, but the system was operated at 10 psig during the 5–year period prior to July 1, 1970. Although the system has been checked for corrosion and rid of leaks, the operator may not raise the MAOP to 10 psig merely by certifying that 10 psig should have been the original MAOP. As with the first system, the operator must uprate the system under Subpart K. Sincerely, Cesar De Leon Director for Pipeline Safety Regulatory Programs dal/192.551 94/05/02#