Cathodic Protection

When corrosion occurs to metallic items, there are anodic and cathodic sites. The formation of these sites can be a result of a difference in the steel composition or a many other reasons such as electrolyte compositions or differences in oxygen concentrations. When corrosion occurs, the anodic site produces electrons which are then consumed at the cathodic site. Therefore, the electrons flow from the anode to the cathode and when the current flows from the metal, corrosion occurs. To prevent this flow of current from the metal will in turn prevent metal loss and this is where cathodic protection (CP) becomes an efficient means of corrosion management. If a positive current flows to the metal, it becomes the cathode and the corrosion rate is reduced.

By installing a CP system, a current is imposed on the system in a direction that makes the structure a cathode and thus prevents further corrosion of the metal.

Cathodic Protection can be either a sacrificial anode cathodic protection (SACP) system or and impressed current cathodic protection (ICCP) system.

The SACP system involves the fixing of a metal more active in the galvanic series of metals with the current flow produced by the driving voltage from the galvanic cell formed which in turn results in the corrosion of the more active metal the anode which in turn corrodes preferentially thus protecting the metal structure being protected.

The ICCP system provides the same outcome but relies on the use of an externally provided driving voltage from a transformer rectifier, in conjunction with anodes which corrode at a very slow rate compared to conventional SACP anodes.

ICM can undertake the design, supply and installation of CP systems capable of providing protection to a variety of clients assets. Additionally, ICM can undertake the monitoring and maintenance of existing CP systems to facilitate the correct performance of any implemented system.

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