Model error assessments of burst capacity models for corroded pipelines

The model errors associated with eight well-known burst capacity models for corroded pipelines, namely B31G, B31G Modified, CPS, the CSA model, the DNV model, PCORRC, RSTRENG and SHELL92, are characterized based on a full-scale burst test database that consists of 150 data points collected from the literature for pipe specimens containing single isolated real corrosion defects. The probabilistic characteristics of the model errors, including the mean values, coefficients of variation and probability distributions, for the burst models are obtained by analyzing the ratios between the test and predicted burst pressures corresponding to the test data applicable to the model. For each of the burst models, separate model errors for short and long defects are also evaluated, whereby the short and long defects are separated by the transition normalized defect length that is identified using the weighted average COV approach.

► Model errors for eight burst capacity models for corroded pipes are characterized.
► Basic statistics of the model errors are obtained based on test-to-predicted ratios.
► Separate model errors for long and short defects are also obtained.
► Results will facilitate reliability-based design and assessment of energy pipelines.