管道防腐层大修案例分析及大修选段原则

通过案例分析并结合现场经验,制定了管道防腐层大修选段的系列原则,即管道防腐层外观的完整与否并不能作为防腐层技术状况的判定依据。在回填土壤的应力作用下,管道在3∶00~9∶00时钟位置的石油沥青防腐层容易出现剥离并屏蔽阴极保护,导致管体腐蚀。中等精度的漏磁检测器所给出的管道内检测结果作为管道防腐层选段大修的依据具有较高的置信度。

A Case Analysis on Pipe Coating Rehabilitation and Determination Principle of Pipe Section to be Rehabilitated

Take the Tieling-Qinhuangdao Oil Pipeline as an example, this paper analyzes the pipe coating rehabilitation and works out the rehabilitation principle to determinate the pipe section to be repaired based on site rehabilitation experience, that is, the appearance of pipe coating should not be taken as the criterion of coating technical state whether good or poor. Due to the stress of backfilled soil, the asphalt coating at 3 : 00-9 : 00 (clock position) is easily disbonding and the CP is shielded, which results in the pipe body corrosion. The internal detection data by MFL with medium precision has a higher confidence level when it is taken as the criterion of the pipe section to be repaired.