Specialized Drainage for Stray Current Control and Pipeline Integrity

Abstract

Rapid urban transit development has increased crossings and proximity between railways and gas pipelines, intensifying direct current (DC) stray current interference. Periodic, high-amplitude DC currents from subway operation accelerate corrosion and threaten pipeline integrity. In China, a natural gas pipeline experienced dynamic interference currents up to 976 A/m2, and a sacrificial-anode drainage system proved ineffective. Conventional forced drainage was infeasible because of spatial, construction, and power constraints. This study1 demonstrated the application of a specialized assembled flexible anode integrated with a solar intelligent potentiostat for forced drainage, which proved to be effective, economical, feasible, and flexible, simplifying construction and improving overall performance.