SEVERITY OF STRESS CORROSION CRACKS IN PIPELINES - CATEGORIES AND RESPONSES

摘要

To facilitate decision making when stress corrosion cracks are found during excavations or in-line inspections of pipelines, a hierarchy of crack-severity rankings has been developed, based upon predicted failure pressure as calculated from the crack sizes. By assuming a crack growth rate, the type and timing of mitigating actions can be determined, as well as appropriate re-assessment intervals for smaller cracks that may remain after the first assessment. The sensitivity of the analysis to variations in pipe dimensions and properties has been examined. Based upon this work, a set of guidelines has been proposed for inclusion in Appendix A of the ASME B31.8S Integrity Management Standard.