Pipeline Safety Interpretation PI-77-0108

Page 1PI-77-0108 December 12, 1977 Mr. Charles H. Kent Supervising Engineer Panhandle Eastern Pipe Line Company P.O. Box 1348 Kansas City, Missouri 64141 Dear Mr. Kent: We apologize for the unusual delay in responding to your inquiry about the appropriateness of applying section 192.555 instead of section 192.557 when lateral transmission lines are up rated to stress levels below 30 percent of SMYS. As your letter clearly points out, many of the requirements of section 192.557 for up rating pipelines to stress levels below 30 percent of SMYS are more stringent than the ones for pipelines being up rated to high stress levels. We believe this distinction was made because most of the lower stress level pipelines are in distribution systems where there is a greater risk to public safety. However, since the requirements themselves do not distinguish between distribution and transmission lines, there may be some unnecessary procedural restrictions placed on up rating lateral transmission lines to low stress levels. In the future, as part of our regulatory reform policy, we will be reviewing the up rating requirements to see what changes may be necessary. Meanwhile, if you feel that the existing requirements are creating a hardship in a particular situation, you may file a petition for a waiver as provided in section 3(e) of the Natural gas Pipeline Safety Act of 1968 (49 USC 1672 (e)). Sincerely, SIGNED Cesar DeLeon Acting Director Office of Pipeline Safety Operations#

Page 2Panhandle eastern Pipe Line Company P.O. Box 1348 Kansas City, Missouri 64141 May 13, 1977 Mr. Cesar DeLeon, Acting Director Office of Pipeline Safety Operations Materials Transportation Bureau Department of Transportation 2100 Second Street, S.W. Washington, D.C. 20591 Re: Federal Pipeline Safety Regulations Sections 192.555 and 192.557 Up rating Pipelines. Dear Mr. DeLeon: The wording of Section 192.557, up rating of lines that operate at less than 30 percent of SMYS, indicates that the requirements are mainly applicable to distribution mains; however, there are a great many small diameter transmission lines supplying distribution systems which operate at pressures up to 700 or 800 psig and still have hoop stresses less than 30 percent of SMYS. It seems that the requirements of 192.555 would die much more applicable and reasonable when up rating these lateral lines. Paragraph 192.555(c) allows an operator to use a previous test or high operating pressure as the test pressure on which to apply the factors of 192.619 in determining the pressure to which a line can be up rated. Is this same procedure available for lines operating below 30 percent SMYS. Paragraph 192.555(d)(1) allows an operator to test in accordance with Subpart J to establish an up rated MAOP. Is this procedure available for lines operating below 30 percent SMYS? If a line is tested in accordance with Subpart J and a new MAOP established, is it necessary to increase the operating pressure in increments when the line is put back in service? This is not required when a line operating above 30 percent SMYS is up rated in accordance with 192.555(d)(1). Your consideration of these questions will be appreciated. Yours truly, Chas. H. Kent, Supervising Engineer#