Interpretation Response #PI-01-0109 ([Puget Sound Energy, Inc.] [Ms. Stephanie J. Kreshel, P.E.])
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Puget Sound Energy, Inc.
Individual Name: Ms. Stephanie J. Kreshel, P.E.
Location State: WA Country: US
View the Interpretation Document
Response text:
U.S. Department of Transportation
Research and Special Programs Administration
400 Seventh St., S.W.
Washington, D.C. 20590
May 30, 2001
Ms. Stephanie J. Kreshel, P.E.
Standards Engineer
Puget Sound Energy, Inc.
P.O. Box 90868
Bellevue, WA 98009-0868
Dear Ms. Kreshel:
This letter is in response to your letter of April 5, 2001, requesting an interpretation of the up rating requirements in 49 CFR Part 192, Subpart K and referencing a March 15, 2001, letter from the Washington Utilities and Transportation Commission (WUTC).
Puget Sound Energy (PSE), a local distribution company (LDC), wants to up rate a steel pipeline in a Class 3 location to a pressure that will produce a hoop stress of less than 30 percent of specified minimum yield strength (SMYS). In 1957, the pipe was pressure tested to 465 psig and the LDC established a maximum allowable operating pressure (MAOP) of 190 psig based on the highest operating pressure during the five-years prior to July 1, 1970. PSE's proposed up rating procedure calls for raising the pressure from 190 psig to 250 psig in four increments of 15 psig.
The proposed up rating pressure increments are in compliance with the requirements of the federal pipeline safety regulations in 49 CFR § 192.553 and § 192.555(c). Although the current MAOP of the pipeline is limited by the pressure the pipeline operated at in the five-year preceding July 1, 1970, as required by § 192.619(a)(3), that paragraph explicitly exempts up rating in accordance with Subpart K from this limitation. The up rating regulations in Subpart K also do not require that a new pressure test be conducted at the time of up rating. And, 192.555(c), which addresses up rating to a pressure that will produce a hoop stress 30 percent or more of SMYS, explicitly allows the use of a previous pressure test as the basis for MAOP, even if the pipeline was not operated to the MAOP during the five years prior to July 1, 1970. Although the use of a previous pressure test is not mentioned in § 192.557, which covers up rating to a pressure that will produce a hoop stress less than 30 percent of SMYS, it makes no sense to rely on a previous pressure test for high-stress pipe and disallow it for low-stress pipe. In any case, § 192.553(d) clearly states that the new MAOP may not exceed the maximum that we would allow for new pipe of the same material at the same location.
Therefore, reliance on a previous pressure test is allowable for up rating to a higher MAOP, providing that the pressure test, de-rated for class location as specified in § 192.619, allows for a maximum allowable operating pressure equal to or greater than the proposed up rated pressure.
If you require further information, please call me at (202) 366-4565.
Sincerely yours,
Richard D. Huriaux, P.E.
Manager, Regulations
Office of Pipeline Safety
Regulation Sections
| Section | Subject |
|---|---|
| 192.553 | General requirements |