Study on sufficiency of reference stress solutions for crack-like flaws for fitness-for-service evaluation

High Pressure Institute of Japan (HPI) has instituted the industrial standard HPIS Z101-2, “Assessment Procedure for Crack-Like Flaws in Pressure Equipment ‒ Level 2,” which addresses the methodology for the evaluation of fitness-for-service for detected flaws in industrial structural components such as pressure vessels, pipes, storage tanks, etc. during in-service inspection. In the standard, reference stress solutions for fundamental structures with surface flaws are prepared for the assessment of the acceptability of the detected flaws. From the viewpoint of the comprehensiveness of available solutions for excessive conditions, additional reference stress solutions for long surface flaw in plate, axially through-wall flaw in cylinder, circumferentially through-wall flaw in cylinder, and through-wall flaw in sphere were required. In this paper, the appropriate reference stress solutions to be adopted for some of the above structures were investigated by comparing the existing solutions in referable codes/standards. © 2019 Trans Tech Publications Ltd, Switzerland.