A galvanic anode, or sacrificial anode, is the main component of a galvanic cathodic protection system used to protect buried or submerged metal structures from corrosion.
The anode is made from a metal with a more “active” voltage (more negative electrochemical potential) than the metal of the structure it is protecting (the cathode). The difference in potential between two metals means the sacrificial anode material corrodes in place of the structure by effectively stopping the oxidation reactions at the metal surface of the structure being protected.
The materials used for sacrificial anodes are either relatively pure active metals or metal alloys. Our sacrificial anodes are generally made from one of four metals: aluminum, magnesium, zinc or iron. They are often used to protect the hulls of ships, water heaters, pipelines, distribution systems, above-ground tanks, underground tanks and refineries.
No external power source is needed, making sacrificial anode systems easy to install. Sacrificial anodes are normally supplied with either lead wires or cast-in metal straps to allow for an easily installed connection to the structure being protected. The lead wires may be attached to the structure by welding or mechanical connections. The anodes in sacrificial anode CP systems must be periodically inspected and replaced when consumed so as to maintain optimum performance.