Status of Proposed Updates to the Weld Residual Stress Guidance for Flaw Assessments in API 579-1/ASME FFS-1

Guidance for weld residual stress (WRS) in flaw assessments of in-service equipment is given in Annex E of the Fitness-for-Service (FFS) standard, API 579-1/ASME FFS-1. Recent progress in the simulation of weld residual stress, and in its verification and validation has provided the opportunity to both simplify and supplement Annex E. Specifically, a tiered approach is recommended with the baseline guidance simplified and harmonized with other existing guidance, while more complicated cases are recommended to be handled with an explicitly described simulation method. The simulation method is the subject of related papers, while this paper focuses on comparison and evaluation of existing guidance for the common cases of cylinder girth and seam welds. A complete draft of recommended guidance has been completed, and intended for publication in the 2014 revision of API 579-1/ASME FFS-1. A supporting basis document which details the underlying methodologies for recommendations has also been completed.Copyright © 2014 by ASME