Arizona Corporation Commission — Pipeline Safety Interpretation

Page 1PI-74-0112 May 03, 1974 Mr. H. R. Garabrant Gas Utilities Safety Engineer Arizona Corporation Commission 1688 West Adams Dear Mr. Garabrant: Thank you for your letter of April 13, 1974, asking whether the class locations prescribed in 49 CFR 192 apply to a liquefied petroleum gas (LPG) line since LPG is a compressed gas in liquid form. The class locations in 49 CFR Part 192 were established under the Natural Gas Pipeline Safety Act of 1968 (49 USC 1671 et seq.) for the safety regulation of pipelines used in the transportation of compressed gases in liquid form. When these liquids, such as LPG, are transported by pipeline by a carrier engaged in interstate or foreign commerce, the transportation is covered by the regulations in 49 CFR Part 195 promulgated under the Transportation of Explosives Act (18 USC B 31 et seq.). We trust this adequately responds to your inquiry. Sincerely, /signed/ Joseph C. Caldwell Director Office of Pipeline Safety#

Page 2April 13, 1974 Mr. Joseph C. Caldwell Office of Pipeline Safety Department of Transportation Washington, D. C. 20550 Dear Mr. Caldwell: Although my office is not specifically charges with approving plans of L.P.G. intra-state pipelines, I have been asked to comment on the proposed program for the design and construction of a six inch L.P.G. pipeline, approximately four miles long in the vicinity of Phoenix. As proposed this line is being built to standards DOT Title 49, Part 195, subparts C, D, E and F. and liquid petroleum transportation piping systems code AISI B 31.4-1971. All seems to be in order, I made a few minor suggestions concerning their specifications, however, I have one question in my mind. Part 195 does not call for class locations and since propane which is the product to be carried, in this case is a compressed gas, we well as being in liquid form, would the class locations as called for in Part 192 be applicable? The company involved has correctly calculated the internal design pressure at 1430 pounds, according to part 195, and it will be the allowable working pressure of this pipeline. All fittings and the line will be hydrostatically tested to permit operation at this pressure. However, the anticipated normal working pressure will be 1,000 PSI. Please advise me as soon as possible regarding the applicability of the reduction of design factor F due to class locations in regard to propane or other L.P. gasses. Sincerely, H. R. Garabrant Gas Utilities Safety Engineer#