Underground corrosion is caused by a natural phenomenon of metal. returning to its original lowest energy state, such as steel returning to its original state of iron oxide or rust. A general definition of corrosion is the deterioration of a material because of a reaction with its environment. Metallic corrosion is considered an electro-chemical process, in that it consists of a series of chemical reactions with a measurable electrical current flow. The rate of corrosion can be controlled by decreasing the current flow from a metal either by increasing the resistance in the circuit or by applying an electrical potential in a manner to offset the natural electrical current caused by corrosion. The methods available for protection depend upon the underground piping layout and whether it is new or existing.
Table of Contents; Introduction, Dielectric Coatings, Types of coatings, Cathodic Protection, Protection System Design Parameters, Cathodic Protection System Design Calculations, Protection System Installation, Monitoring and Maintenance.