AC Interference Effect on NG Pipeline and its Mitigation Techniques

All gas pipeline system operators should produce and demonstrate compliance with operational and maintenance philosophies, which include integrity management policies, procedures and safe systems of work throughout their operational life. They should identify all hazards that may impact the system integrity with respect to tolerable individual and societal risk. Risk assessment should be undertaken, mitigation measures established and any residual risk associated with the management of each risk mitigation strategy must be defined and risk ownership established. A credible integrity risk is associated with Alternating Current (AC) induced corrosion of underground steel pipelines that are routed in close proximity to high voltage overhead electrical power systems. This document provides information about AC interference effect on pipeline and demonstrates credible risk mitigation techniques with integrity management. It also describes safety measures and new mitigation technique to avoid electromagnetic interference generated by electric line on underground natural gas pipeline during installation and operational life where the pipeline is laid in common ROU. It shall be emphasised that the owner/operator bears responsibility for the safe operation and maintenance of pipeline system and implement required means and methods to assure integrity of system throughout the design life of the pipeline system.