Tennessee Public Service Comm — Pipeline Safety Interpretation

Page 1Mr. John Searcy Engineering Division Tennessee Public Service Comm Cordell Hull Building Nashville, Tennessee 37219 Dear Mr. Searcy: This letter id a further reply to your letter of October 5, 1971, in which you posed the question in paragraph 192.197(c)(2), it is stated that a service regulator and a monitoring regulator are required. Would you consider two (2) regulators in series both set at the same pressure as being a service regulator and a monitoring regulator? In answer to your question the requirements of 49 CFR 192.197(c)(2) will be met with two regulators in a series, but it will be necessary to have some difference in the setting of the two regulators to avoid operating difficulties. The sketches that you submitted of the various options open for the design of a regulatory installation conforms to the intent of §192.197(c). Sincerely, /signed/ Joseph C. Caldwell Acting Director Office of Pipeline Safety DB C:\WP51\INTERPRT\192\197\71-11-11 1#