Burst strength analysis of pressurized steel pipelines with corrosion and gouge defects

The development of a defect on pressurized pipeline could easily threaten its structural integrity and if not managed on time could lead to burst failure. One of the safest ways to mitigate against this type of failures is to determine the residual strength of the damaged pipe section by estimating the safe operating pressure. Gouge and pit corrosion are two examples of regular defects found in steel pipeline walls that result in lower burst strength. Studying how defects impact the performance of steel pipelines could offer useful information on how to consider, treat and in a way prioritise their level of threat whenever presented with the decision. To achieve this, burst pressure analysis using 3D finite element analysis were carried out to simulate both cases of defect damage on pipe structure considering their different geometries. A parametric study carried out suggests both defect configurations reduce burst strength of pipelines, but the severity of damage depends on most importantly the length and depth of the defect as well as the mechanical and configuration of the pipeline. The simulated results suggests, the geometric representation presented by idealised pit corrosion profile in the pipeline longitudinal direction proves to have the greater influence on lowering burst strength. Thus, pit corrosion appears to be more damaging to the pipelines.