Safety evaluation standards for in-service oil and gas pipelines with defects

In practical, some pipelines with defects are still in service. Regarding this aspect, this paper reviews domesticand international standards for safety evaluation of pipelines with defects and presents ASME B31G, API RP 579, DNVRP-101 and PCORRC evaluation methods as well as the advantages and disadvantages and scope of application ofSY/T 6477-2000. ASME B31G and API 579 are relatively conservative, while several evaluation standards revised basedon ASME B31G improved a lot in their accuracy; DNV RP-F101 and PCORRC are suitable for the medium/high-strengthpipelines with defects. In the evaluation process, it is recommended to choose an evaluation standard that allows simplecalculations but gives comparatively accurate results, and to revise the common evaluation standards according to actualneeds and propose corresponding standards. Moreover, finite element numerical (FEM) calculation is recommended for thepipelines with complex structural defects and multiple load coupling defects.