榕山—佛荫输气管道外腐蚀分析及控制措施

通过对榕山－佛荫输气管道进行智能检测发现，管道石油沥青防腐层损坏严重。从管道膜下腐蚀、环焊缝处“死角区”以及阴极保护极化电位不足等方面，对该条管道外壁产生腐蚀的原因进行了分析，提出了管道外腐蚀控制措施和建议。

Analysis on the External Corrosion and Corrosion Control for Rongshan-Foyin Gas Transmission Pipeline

The intelligent pigging exposed that the asphalt coating deteriorated to a great extent in Rongshan-Foyin gas transmission pipeline. Two problems existed,one was that the unprotected area on pipe surface (mostly at 3-9 o'clock position of pipe) continuously grew up due to the asphalt coating ageing and water aggregation,especially around the circumferential welded seam of the pipe,where the protection current of CP could not be reachable;the other one was that the polarization potential of CP was insufficient. Therefore, an analysis on the external corrosion of pipe wall has been conducted,the corrosion control measures against the external corrosion of the pipeline is put forward.