Ensuring pipeline reliability with cable maintenance

Many medium voltage power cables connecting substations, switchgear, and large pump motors in pipeline pumping stations are over 25 years old. The reliability of the station can be compromised by medium voltage cable failures. Factors identified that affect station reliability include cable age, original cable installation practices, craft work, weather exposure, length, and increasing electrical loads as pipeline capacities are expanded. Maintenance philosophies vary on what reliability actions should be taken and when. Many times, because of lack of downtime, lack of accurate end of life measurements, and budgets, maintenance actions are delayed. Run to failure, visual inspection, IR inspection, cable testing, cable rejuvenation, and cable replacement are potential choices. To test cable rejuvenation and evaluate the benefits of applying risk analysis to pipeline pumping stations, one pipeline pumping station was selected for a demonstration project. The planning, schedule, process, and downtime required for the project are reviewed. Developing a ranking system for cables and then rejuvenating the cables on the list proactively provides an approach that can lead to higher pipeline reliability.