PR644-183602-R01 Cathodic Protection Design Considerations for Facilities with Congested Areas

The surface area method is often used to design cathodic protection (CP) systems for congested area facilities where at-grade and below-grade coated and uncoated metallic assets, which are electrically interconnected, exist. The surface area method provides an estimate of the protection current requirement, but is not adequate to calculate current distribution. This work presents a computational approach to model current distribution for the congested area facilities. The approach consists of developing a finite-element based model for a given facility, and then using the model to calculate the current distributions to the various at- and below-grade metallic assets. Two separate congested area facilities were modeled using the approach: (i) a storage tank terminal, and (ii) a gas compressor station. This work demonstrated that the approach can be used to design CP systems for the congested area facilities and is an improvement compared to the surface area method.