Memo: Internal — Pipeline Safety Interpretation

Page 1December 19, 1978 SUBJECT: Request for Interpretation of Section 192.747 FROM: Chief, Southern Region TO: Associate Director of Pipeline Safety Regulation, DMT-30 The attached letter highlights some of the problems we find in trying to enforce section 192.747, i.e., many buried valves which, id designated as key valves, becomes a continuing maintenance problem. We have taken the position that one designated valve that controls the operator's supply does not meet Section 192.747 except (1) where only one valve exists on the distribution main and (2) where the system is extremely small, rural in nature, and does not have a well defined commercial area. Therefore I request your interpretation of the following questions: (1) For a typical distribution system having a well defined business district, and class 1, 2, and 3 areas; will one key valve suffice assuming that the valve controls the system supply and that multiple main valves do exist within the system? (2) If the answer to 1 above is "no," what minimum number of key valves would suffice? What system areas should they control? James C. Thomas Attachment DB C:\WP51\INTERPRT\192\747\78-12-19 1#