Corrosion protection system design for the storage tank bottom plate

Corrosion is one of the most prevalent causes of leaks in the aboveground storage tank. Consequently, in addition to other protection measures, the use of a cathodic protection system (CP) on the soil side of the aboveground storage tank is beneficial. The selected method for the protection of large structures by CP is an impressed current cathodic protection system. In the present paper, design and selection of the cathodic protection system to be utilized are based upon specification and engineering parameters such as Material, operational and environmental requirements as well as Economics. Also anticipated changes in soil characteristics and coating efficiency have been considered in choosing and sizing cathodic protection system, type and equipment. The impressed current system is selected for the protection of external surfaces of tank bottom plate in response to variable conditions, such as soil resistivity and coating quality. In this type of protection, rectifiers will provide the lowest-cost protection current where AC power is available and where the current demand will exceed that economically obtained from galvanic anodes.

Keywords:

Cathodic Protection , Corrosion , storage tank , Impressed Current.