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Interpretation Response #PI-74-017 ([Tennessee Public Service Commission] [John Searcy])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Tennessee Public Service Commission

Individual Name: John Searcy

Location State: TN Country: US

View the Interpretation Document

Response text:

Mr. John Searcy

Engineering Division

Tennessee Public Service Commission

Cordell Hull Building

Nashville, TN 37219

Dear Mr. Searcy:

This responds to your letter of February 21, 1974, concerning uprating requirements for steel
pipelines operated at 100 psig, or more, with hoop stresses less than 30 percent of SMYS. You
ask whether "the pressure must be increased in the increments required to the desired maximum
allowable operating pressure times the appropriate factor in the table in 192.619(a)(2)(ii)?"

Subject to the requirements of section 192.621, the maximum allowable operating pressure
(MAOP) for the pipelines to which you refer may not be increased above the lowest pressure
determined in accordance with action 192.619(a). In uprating to a pressure permitted by section
192.619(a)(2)(ii), a strength test must be performed. The increments prescribed by section
192.557(c) apply to the increase in pressure between the existing MAOP and the test pressure or
the desired MAOP multiplied by the appropriate factor in section 192.619(a)(2)(ii).

Thank you for your interest in pipeline safety.


s/Cesar DeLeon

Joseph C. Caldwell


Office of Pipeline Safety

Regulation Sections

Section Subject
192.557 Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent of SMYS: plastic, cast iron, and ductile iron pipelines
192.621 Maximum allowable operating pressure: High-pressure distribution systems
192.63 Marking of materials