Stress Corrosion Cracking of a Liquid Transmission Line

Localized corrosion, and the associated stress corrosion cracking compromised the integrity of the 610 mm diameter X-52 Rainbow pipeline. Following incidents of rupture, an extensive excavation effort was undertaken to locate and rehabilitate the line. Limited correlation’s were noted with the type of soil, and the operating line pressure. A elastic-plastic fracture model was developed to manage the SCC on this pipeline. Hydrotests were deemed necessary in certain portions of the line, based on model predictions on susceptibility to failure. Additionally, the model was further applied to define hydrotest frequency.