Correcting Non-uniform Potential distribution and Interference Problems in the Cathodic Protection System of a Gas Compressor Station

摘要

After a period of 12 years of operation of the cathodic protection system in a gas compressor stations, the CP potential distribution hadthanged for various reasons, such as pipelines coating degradation, isolating flanges failures, alterations in pipeline systems, and reinforced concrete foundation (RCF) systems. Isolating flanges failures creates galvanic corrosion between the pipelines and the Cu grids of the earthing system, and the steel rods in the RCF, which consumes part of the CP currents, thus non-uniform potential distribution. The extent of CP current required had become so high that was beyond the capacity of the rectifiers. Some areas had become seriously underprotected and some others seriously overprotected. Meanwhile the interference with other neighboring foreign buried pipeline, also had increased. In this paper the results of correcting measures for these problems is reported.