Maadoitustanko

Maadoitustanko, also known as a "sacrificial tank" or "sacrificial anode," is a protective metal component used in corrosion prevention systems, particularly in marine and industrial applications. Its primary function is to protect more valuable metal structures from corrosion by sacrificing itself through a process called galvanic corrosion.

In a galvanic system, the maadoitustanko is made from a more electrochemically active metal, such as zinc, aluminum, or magnesium, compared to the metal it is intended to protect, such as steel or iron. When both metals are immersed in an electrolyte, such as seawater or soil, the maadoitustanko acts as the anode, corroding preferentially. This occurs because the anode has a lower electrochemical potential than the cathode (the metal being protected), causing electrons to flow from the anode to the cathode. This electron flow prevents the cathode from corroding, effectively shielding it from oxidation.

Maadoitustanko systems are commonly used in ship hulls, offshore platforms, pipelines, and underground storage tanks to extend their lifespan by minimizing corrosion damage. The effectiveness of the system depends on factors such as the type of metal used, the size and shape of the anode, the conductivity of the electrolyte, and the surface area of the structure being protected. Over time, the maadoitustanko will degrade and must be replaced periodically to maintain protection.

While highly effective, maadoitustanko systems require proper installation and monitoring to ensure optimal performance. Improper sizing or placement can lead to inadequate protection or accelerated corrosion of the anode itself. Alternative corrosion protection methods, such as coatings or cathodic protection using impressed current systems, may also be employed in conjunction with maadoitustanko for enhanced durability.