QUALIFICATION OF A NON-STANDARD PIPING COMPONENT FOR ASME PRESSURE PIPING APPLICATIONS

摘要

In 1991 one of the authors of this paper coauthored a paper [1] on how to qualify a non-standard piping component for ASME B31.1 and B31.3 services. Since that time a number of ASME piping qualification standards have been written or are under development that affect how piping components should be qualified. This paper updates the 1991 paper and uses a non-standard piping component, in this case a mechanical joint, to demonstrate a method to qualify non-standard piping components for ASME non-nuclear and nuclear services. The herein documented testing applies the various more current qualification requirements to meet ASME B31 and Section III, Class 2 and 3 Code service rules. The paper explains the intention of the various Code requirements, outlining the mechanical tests and calculations used to demonstrate ASME Code conformance. This paper also discusses non-traditional piping failure mechanisms, mechanisms other than rupture and fatigue, such as component disassembly due to the component being a compression fitting. Similar non-traditional failure mechanisms are often encountered in other types of non-standard components such as clamps, flared and flareless joints, rolled and expanded joints, and proprietary components. The discussion of non-traditional failure mechanisms is extended to include how the tests for these failure mechanisms could translate into ASME pressure piping requirements to assure a safe piping system. The paper concludes with recommendations for improving the ASME pressure piping Code requirements as they apply to non-standard piping component qualification.