Oklahoma Corporation Commission — Pipeline Safety Interpretation

Page 1Mr. Dennis Fothergill Manager, Gas Pipeline Safety Oklahoma Corporation Commission Jim Thorpe Office Building Oklahoma City, Oklahoma 73105 Dear Mr. Fothergill: Your June 29, 1989, letter asks for written confirmation of our informal view that a proposed hazardous liquid pipeline would not be subject to Part 195 if it is constructed in a nonrural area of high density polyethylene plastic pipe (PE 3408) and is operated at a stress level less than 20 percent of its specified minimum yield strength (SMYS). Section 195.1(b)(3) provides that transportation of a hazardous liquid through a pipeline that operates at a stress level of 20 percent of less of SMYS is not subject to Part 195. Our opinion provided to you by telephone was based on our preliminarily deciding that plastic pipe operating at 20 percent or less of the design pressure using the long-term hydrostatic strength of the plastic pipe would be similar to the ?195.1(b)(3) exemption for steel pipe. However, upon further consideration of the background and meaning of this intended to apply to plastic pipe. Thus, the proposed pipeline would be subject to the applicable requirements of Part 195. Under ?195.7, the operator of the proposed plastic pipeline would have to notify us of the intent to transport a hazardous liquid in a pipeline that is constructed of material other than steel at least 90 days before such transportation is to begin. Within that 90 day period if we determine the proposed transportation would be unduly hazardous, we will order the operator not to transport the hazardous liquid in the manner proposed until further notice. We have in fact received such a notice from Mid-Continent Pipe Line Company for a gathering system in Oklahoma City and are reviewing the proposed transportation. Sincerely, /signed/ James C. Thomas Acting Director Office of Pipeline Safety DB C:\WP51\INTERPRT\195\1\89-08-22 1#