Titanium anodes coated with mixed metal oxides (MMO) operate on a different basis than conventional galvanic anodes. They require the use of an external power source (potentiostat), which causes polarization of the anodes and the protected element.
Magnesium galvanic anodes are commonly used for cathodic protection of underground constructions (tanks, pipelines) and for protection of internal surfaces of tanks containing water (eg. water heaters, hot and cold water tanks, condensers, heat exchangers).
Aluminum galvanic anodes are used for cathodic protection in an environment containing chloride ions, because in fresh water and soil aluminum passivates. These anodes are used both for the protection of onshore and offshore constructions. They are used to protect such structures as: steel sheet pilings of wharfs, steel piles of reloading posts in ports, steel anti-flood barriers, etc.
Zinc galvanic anodes are used for cathodic protection both in the environment of salt and fresh water. They are used to protect marine onshore and offshore constructions, vessels (ships, yachts) and underwater pipelines.