Mitigation of Soil-Side Corrosion on Double-Contained Aboveground Storage Tank Floors

摘要

Double-bottom tank installations and tanks with high-density polyethylene (HDPE) liner containment often create difficult corrosion control challenges. Current from external cathodic protection (CP) systems will not flow through the lower floor of a double-bottom tank or a HDPE containment liner. CP can be applied only by installing anodes between the upper floor and lower floor, or containment liner. Many tanks have been upgraded with double bottoms, or under-tank liners (Figure 1), and a variety of CP systems have been installed on these tanks. Some interstitial space CP systems have become ineffective, however. Replacement without taking the tanks out of service and removing the floors is not practical or economical. Operating the tanks without soil-side corrosion control on the fluid containment floor is not an acceptable option for many tank owners and regulatory authorities.