Application of Specialized Assembled Flexible Anode to Stray Current Drainage in Pipelines

Paper ID: C2025-00110 ABSTRACT: With the rapid development of urban transportation systems, the occurrence of intersections and parallels between urban railway lines and buried gas pipelines has become increasingly prevalent. The severe and periodic DC stray current generated during railway line operations accelerates pipeline corrosion, thereby significantly impacting pipeline safety. A natural gas pipeline in Nanjing, China has long been affected by dynamic DC stray interference currents from the subway (with a maximum DC current density reaching 976 A/m2). The existing drainage system with sacrificial anodes fails to address on-site interference issues effectively. Moreover, due to geographical location constraints, construction conditions, and power supply limitations, traditional forced drainage systems cannot be properly installed or operated. Therefore, this paper proposes the adoption of a new specialized assembled felexible anode combined with a solar intelligent potentiostatic device for forced drainage purposes. Following implementation of this system, under-protection states of the pipeline are successfully suppressed while corrosion is effectively alleviated. Application results demonstrate that the specialized assembled felexible anode combined with solar intelligent potentiostat drainage system offers remarkable effectiveness in draining excess current while having minimal installation position restrictions and convenient construction processes. Furthermore, it exhibits excellent economic performance and holds significant potential for widespread application.