Illinois Commerce Commission — Pipeline Safety Interpretation

Page 1PI-75-0106 June 12, 1975 Mr. Harold E. Shutt Chief Engineer - Gas & Electric Illinois Commerce Commission 527 East Capitol Avenue Springfield, Illinois 62706 Dear Mr. Shutt This refers to your letter of May 26, 1975, notifying us of your advice to the Central Illinois Public Service Company (CIPSC) about uprating a distribution line to a pressure permitted by Section 192.619(a)(2)(ii) of 100 psig, or more, that will produce a hoop stress of less than 30 percent of SMYS. You stated, that in accordance with Advisory Bulletin No. 75-2, the line may be uprated "without performing a strength test." While your advice is not incorrect, we believe that it may be misleading. By informing CIPSC that a "strength test" is not required in uprating to a pressure permitted by Section 192.619(a)(2)(ii), CIPSC may not understand that the published interpretation of this Office is that some type of pressure test is required, whether it be a strength test or a leak test. The purpose of the interpretation to which you refer in Advisory Bulletin No. 75-2 is to clarify this point. Accordingly, we suggest that you so notify CIPSC. Sincerely, Original signed by Joseph C. Caldwell Director Office of Pipeline Safety#

Page 2STATE OF ILLINOIS Illinois Commerce Commission 527 EAST CAPITOL AVENUE SPRINGFIELD, ILLINOIS 62706 May 26, 1975 Director, Office Pipeline Safety Department of Transportation 400 7th Street, S.W. Washington, D. C. 20590 Re: Notice of interpretation Dear Sir: Central Illinois Public Service Company in Springfield, Illinois, has a 4.500" O.D. distribution line and a 2.375" O.D. distribution stub, both operating at 275 psig. They desire to increase the operating pressure on the 2.375" O.D. and 4.500" O.D. line segments to 350 psig. The 2 1/2 mile 4.500" O.D. line segment was installed in 1930. The line segment is 0.237 inch wall thickness, has the original coating still intact, is of welded construction, has been under rectifier cathodic protection since 1960 and has no leaks. The pipe grade is unknown. The actual stress, expressed as a percent of SMYS, is 10.8% at 275 psig and 13.8% at 350 psig. This line is in a Class 2 location. The 3 mile 2.375" O.D. distribution stub was installed in 1966-67 with welded construction. This 0.15 4 inch wall thickness coated pipe is under cathodic protection and no leaks exist. The pipe grade is furnace butt- welded with a 25,000 psi minimum yield. The actual stress, expressed as a percent of SMYS, is 8.4% at 275 psig and 10.7% at 350 psig. A portion of this line is in a Class 3 location. The question which occurs in this upgrading procedure is whether or not a strength test is required. In OPS Advisory Bulletin No.74-7 this question was asked. In this interpretation, OPS has said that a strength test must be performed in accordance with Section 192.619 (a) (2) (ii) . However, in a later OPS Advisory Bulletin No. 75-2 a question was asked about the interpretation in the Advisory Bulletin No. 74-7. Here OPS's interpretation was that the term strength test was an overstatement of the requirement. Central Illinois Public Service Company has requested a waiver but a waiver appears unnecessary. Having served on the Technical Pipeline Safety Standards Committee when the standards were adopted, I do not believe the strength test was intended to apply to lines operating at a pressure that will produce a hoop stress less than 30% of SMYS. OPS' second interpretation that the strength test was an overstatement of the requirement, appear more correct. We are advising Central Illinois Public Service Company with a copy of this letter that this distribution line can be upgraded without performing the strength test. Sincerely, Harold E. Shutt Chief Engineer - Gas & Electric#