Investigation of the Burst Pressure of a Pipeline with an Inclined Corrosion Defect Using FE Analysis

Abstract

The steel pipelines used for oil and gas transportation are subjected to corrosion during the service life, which reduces the strength of the pipelines. The maximum operating pressure of a corroded pipeline depends on the remaining strength/burst pressure of the pipeline. Design codes provide models to predict the remaining strength of a corroded pipeline, focusing on corrosion defects parallel to the pipe axis. Sometimes, corrosion defects are aligned at an angle with the pipe axis, which may influence the burst pressures of the corroded pipelines. ASME B31G code recommends defining the corrosion length depending on the angle of inclination of the corrosion defects. This paper presents a numerical study to investigate the effect of corrosion defects inclined at various angles on the burst pressure of the pipeline to validate the ASME B31G recommendation. Based on a parametric study, a model is proposed to predict the burst pressure of a pipeline with an inclined corrosion defect. The ASME models are evaluated using the proposed model as well as the numerical results.