Crack Propagation Modeling and Crack Arrestor Design for X120

The new, higher grade pipeline steels provide an opportunity to reduce pipeline costs by enabling a shift to higher pressure at reasonable wall thickness. However, these higher operating stresses place greater demands on the pipeline, particularly when a running fracture is considered. Several studies have shown that intrinsic arrest cannot be counted on for these grades under all operating conditions. In such cases, crack arrestors will be needed. This paper presents results obtained using CSM’s proprietary PICPRO^® finite element code to predict the performance of crack arresters on X120 pipes, and shows that the predictions agree well with full-scale experimental results obtained in arrestor trials.