Assessment of cracks in pipelines is one of the important areas of an integrity management plan. Currently, a number of fracture mechanics-based methods are available for crack assessment. However, how to select an appropriate methodology (or methodologies) that would both provide reliable results for immediate and future integrity assessment, and form a technical basis for developing a safe and cost-effective integrity management plan, is a significant concern. Moreover, inconsistent results have been found between assessment methods for the same features in the same pipelines, which further raises concerns about the advantages and limitations for each of the assessment methodologies. Therefore, a thorough review of the methods, together with a clear understanding of the fundamental fracture mechanics principles that drive them, is essential in order to develop consistent guidance for crack-like flaw assessment in pipelines. In this paper, a critical review is given to failure assessment diagram (FAD), in particular the API 579-2000 fracture mechanics assessment method for crack-like flaws. Illustrations, arranged by applicability to field examples, demonstrate the approach.
Ke~/~ords: SCC, crack assessment, failure assessment diagram, FAD, elastic-plastic fracture mechanics, crack initiation, ductile tearing, tearing instability, leak, rupture, API 579, BS7910