Study on the influence of the difference of anti-corrosion coatings on CP potential in pipelines

The cathodic protection was one of the main corrosion protection methods for buried metal pipelines. However, the cathodic protection between multiple pipelines in the pipeline corridor interfered with each other, and combined protection was the key to solve this problem. Under this condition, the target pipeline's cathodic protection potential was affected by the other pipelines, leading to inaccurate test results. Therefore, this paper studied the influence of the different coatings on IR drop in pipelines. The results showed that the IR drop of the target pipeline was mainly related to the quality of the total anticorrosive layer in the pipelines, showing a logarithmic relationship, and the more pipelines in the pipeline network was, the smaller the IR drop of the target pipeline caused by the stray current caused by the difference of anticorrosive coatings between pipelines was.