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.