Degradation Ranking of Distressed PCCP and Repair Prioritization

Many power plants and utilities implement a condition assessment program for their pipelines to identify distressed pipes and repair them as necessary based on the condition of the pipes. Based on the result of the condition assessment (including electromagnetic or visual and sounding inspections), a failure margin analysis is conducted to prioritize the distressed pipes for repairs. Generally, the condition assessment and repairs of highly distressed pipes must be completed within the limited duration of a shutdown. This paper presents an approach of preparing a pipe degradation ranking (ranking of distressed pipes in need of repairs) to assist the pipeline owners in planning and prioritizing the pipe repairs in the current and future shutdowns. It describes the criteria for considering the condition assessment results for ranking the distressed pipes and prioritizes them for repairs. It also discusses the phased repair solutions when the shutdown duration does not allow complete repairs for all distressed pipes.