Pipeline Coating Resistance Estimation Using CP Rectifier Influence

Pipeline cathodic protection (CP) designs and alternating current interference studies are heavily dependent on the quality of the pipeline’s coating. Coating resistance is often coarsely estimated using established values from literature where pipeline age, coating type, and subjective operator feedback are used as guiding parameters. In practice, coating resistance is also heavily dependent on installation quality, historical pipeline operating conditions, and repair activity. This article uses voltage-drop influence survey data from a CP rectifier to estimate a pipeline’s attenuation constant and corresponding coating resistance. Additional details are provided elsewhere.1