There are many threats to in-service pipelines, and pipeline operators have robust integrity management plans and programmes to counter such threats - indeed, many regulators demand such plans and programmes. Although not an exhaustive list, most anomalies that affect pipeline integrity can be identified as falling into one of three categories: Q: Three-dimensional, volumetric metal loss, such as corrosion, pitting and gouging. Q: Geometric, or deformations, such as dents, wrinkles, bending strain etc. Crack-like, for example lack of fusion, hydrogen cracks, fatigue and stress corrosion cracking (SCC). Published methodologies are available for the assessment of each of the above anomaly types; for example, remaining strength (RSTRENG) within ASME B31.G for corrosion anomalies, API RP 1183 for dents, and API 579 or BS 7910 for assessing cracks. Extensive research, full-scale testing and numerical modelling have validated such methodologies, which are widely accepted and are referenced in many codes and regulations, including CSA Z662:19 and the PHMSA regulations.
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