Method and apparatus for controlling steel corrosion under thermal insulation (CUI)

Galvanic anodes and barrier corrosion control for metal pipelines, tanks, and equipment under thermal insulation includes the use of pure aluminum and aluminum alloys in fresh water at high temperatures to protect steel elements in hot water without sufficient chlorides. Sacrificial aluminum and sacrificial zinc-aluminum powders in a mixed primer provide long-term, effective corrosion control of steel under thermal insulation can be achieved in all water temperature ranges regardless of the presence of sufficient chlorides. At temperatures below 75° C., the zinc particles in the primer act to protect the substrate steel. At temperatures above 75° C., the aluminum particles in the primer, and galvanic aluminum tape protect the substrate steel in chloride free neutral pH water and also reduce the consumption of zinc particles in the primer. When the electrolyte water for CUI is sufficiently contaminated with chlorides, the aluminum particles in the primer and the galvanic aluminum become active.