Pipeline Pigging & Integrity Management Conference

The longitudinal seam weld fracture toughness of 36-inch OD x 0.406-inch WT, Gr. X52 pipe was evaluated using both Charpy V-notch (CVN) and Crack Tip Opening Displacement (CTOD) testing. Both testing results were converted to the fracture toughness parameter, K, using the methodology outlined in API 579-1/ASME FFS-1 Annex 9F. The correlations between fracture toughness and CVN data results in a large range of toughness values. However, the correlation between fracture toughness and CTOD data results in a single toughness value. This paper describes the fracture toughness calculations and how these results are implemented for pipeline fracture mechanics analyses. This is relevant to engineers and managers as it shows the technical differences between completing CVN vs. CTOD testing for pipeline integrity management assessments.