Citizens Gas & Coke Utility — Pipeline Safety Interpretation

Page 1November 23, 1971 Mr. D. J. Hendrickson Director, Pipeline Safety Division Indiana Public Service Commission 901 State Office Building Indianapolis, Indiana 46204 Dear Mr. Hendrickson: We have now had an opportunity to have your letter of September 30, 1971, reviewed in detail by our Technical Division. With regard to the two cases you mentioned you are correct in your statement relative to Section 192.511(c) that in effect our regulations do not specify a test pressure above the desired operating pressure for service lines operating in the range of 90 psig to 20 percent of SMYS. However, you must refer to the requirement that is specified in Section 192.619(a)(2)(ii), as amended on November 10, 1970, copy enclosed. This specifies that in order to operate a pipeline at 100 psig or more, it must be tested according to the limits shown in the table incorporated in the regulations. The test pressure for new lines to operate over 100 psig will always exceed the maximum allowable operating pressure according to the provisions of Section 192.619(a)(2)(ii). The only situation where a test pressure of a new pipeline is less than the permitted operating pressure is for a line that will operate between 90 and 100 psig. This variation was included based on strong comments received during rule-making and on recommendation of the TPSSC. These claimed that there was too much existing equipment designed for 100 psig. Since this is a leak test and not a strength test, it was concluded that this would not derogate safety. The same reasoning applies to the test requirements in Section 192.509 for pipelines to operate at or below 100 psig. There is a slight discrepancy existing in the regulations in that Section 192.509 states "at or below 100 p.s.i.g." while Section 192.619 (a)(2)(ii) states "100 p.s.i.g. or more." This will be corrected in our next miscellaneous amendments to the regulations. DB/dal/192.509 71-11-23 1#

Page 2We trust that this will answer your question. If you have any further questions, please feel free to contact us. Sincerely, /signed/ Joseph C. Caldwell Acting Director Office of Pipeline Safety DB/dal/192.509 71-11-23 2#