Interpretation Response #PI-77-022
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
September 21, 1977
Mr. Gunter Schlicht
One Northwood Drive #5
Orinda, California 94563
Dear Mr. Schlicht:
Your letter of July 7, 1977, requests an interpretation of the applicable requirements of Parts 192 and 195 relating to the design and testing of pipeline flanges. Your specific question is: are the requirements of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 (Boiler Code) considered as an equivalent as intended in Section 192.147 to the referenced specifications for flanges in Part 192? Also, does the Boiler Code meet the requirements for flanges of Section 195.126 in Part 195?
The Boiler Code, which is referenced in both Parts 192 and 195, and the ANSI B16.5 and MSSSP-44 specifications that are referenced in Part 192 are intended for the conventional design flanges that would be manufactured by casting or forging rather than the convoluted design that would be folded into shape.
In Appendix II, Paragraphs UA-45 thru UA-59, inclusive, of the Boiler Code, the procedure for designing flanges for manufacture by casting or forging is set forth. It is suggested in this Appendix that if the procedure set forth is not appropriate for the design, then in order to establish allowable working pressures, the flange should be proof tested under the provisions of the Boiler Code, Section UG-101, Proof Tests, to establish maximum allowable working pressure. The testing required by UG-101, that is applicable to all pressure vessels, is more severe and thorough than that required by any of the other referenced specifications for flanges.
It is our opinion that a detailed design and stress analysis supported by a proof test under the provisions of UG-101 of the Boiler Code provides the equivalent level of safety intended by Section 192.147.
Section 195.126 states, with respect to a flange connection, that the "connection as a unit must be suitable for the service in which it is to be used." It does not provide any standard or test method to be used to determine the suitability.
It is our opinion that the stress analysis and Boiler Code testing under the provision of UG-101 would be sufficient to determine whether flange connections are suitable under Section 195.126.
Office of Pipeline
|§ 192.147||Flanges and flange accessories|