PR-273-0323-R01 A Review of Methods for Assessing the Remaining Strength of Corroded Pipelines

The objective of this report is to investigate failure pressure predictions made by common assessment methods used by the pipeline industry, such as ASME B31G, Modified ASME B31G, RSTRENG and others against recorded burst test pressures. The analysis consisted of a number of sensitivity studies or ‘cases’, representing different flow stress definitions and material properties. The assessment methods were applied
to an extensive database of burst test results which includes the results of various tests conducted by GL on higher strength line pipe material (grade X80 and X100), which have previously not been published.

The ASME B31G or the Modified ASME B31G methods can continue to be used to rank/screen defects following ILI. Burst test data on line pipe with real corrosion defects in strength grades above X65 is not available. For higher strength pipe, remaining strength assessments can be conducted using RSTRENG as this method is shown to predict failure pressures lower than the recorded failure pressures in line pipe with machined defects up to grade X100.