Safe burst strength of a pipeline with dent–crack defect: Effect of crack depth and operating pressure

Abstract

A defect that contains both dent and crack, often known as dent–crack defect, may lead to a failure due to rupture or leak in the pipe wall. Hence, the pipeline operator becomes concerned about the performance and safety of the pipeline when a dent–crack defect is diagnosed. A research was recently completed at the Centre for Engineering Research in Pipelines, University of Windsor to study the effect of the crack depth on the safe pressure capacity (burst strength) of 30-inch diameter and API 5L X70 grade linepipe. This study found that the dent–crack defect with crack depth of 70% of wall thickness can reduce the pressure capacity by 55%. This paper discusses the test specimens, test setup, test procedure, test results, and data obtained from finite element analyses.