Do you realize how important its function is?
Cathodic protection is one of the electrochemical methods of protecting metal against electrochemical corrosion, where an external anode is attached to the protected structure. In this way, the surface of the protected metal becomes a cathode – an electrode on which the depolarisator reduction reactions take place, and no metal oxidation process occurs, i.e. its corrosion. To ensure safe long-term use, manufacturers cover the inner side of the tank with a glass layer of ceramic enamel. The degree of coverage with enamel in the process of industrial enamelling exceeds 99.9% according to the quirements of DIN 4753 part. 3. Nevertheless, small pores that expose the tank to corrosion are inevitable. Therefore, the anode must be an integral part of every tank. Magnesium anodes are made of MgAl6Zn3 alloy, in accordance with PN-EN 12438: 2017-10, which specifies the chemical composition for magnesium alloys for cast anodes. They have the form of a metal cylinder made of silvery-white metal. The magnesium anode gradually dissolves, and after some time it completely disappears. At the same time, the active tank protection is stopped (for example a boiler) and steel sheet is more exposed to corrosion. Therefore, the anode should be replaced every 18 months, and in some specific conditions every 15 months. Our experience shows that many users neglect to do this at all.