Recoating SCC on Gas Pipelines Without Grinding

Abstract

Considering both safety and cost-effectiveness in repairing SCC colonies, TC Energy and Blade Energy Partners conducted an engineering assessment to determine whether SCC colonies with depths of 20, 30, and 40%wt in base material and DSAW pipe can be left in a gas pipeline without grinding out provided that the fracture toughness and crack size conditions are met, and the features are recoated properly with a high-performance coating system. The operator would choose the safety level for recoating/grinding based on a fitness-for-service assessment. These findings are based on a literature review and verified by small- and full-scale testing. The product of the work is an assessment tool that identifies SCC cracks that are appropriate for recoating without grinding.