Exposed steel in a moist underground environment will naturally oxidize (corrode) unless protected in some way. Eventually the corrosion will result in perforations of steel underground fuel tanks and piping. Coating or galvanizing provide some protection but and non coated areas or scratches in galvanizing provide an area for concentrated metal loss and failure.
Cathodic protection is an effective and reliable method of protecting metallic components subject to corrosion.
Cathodic protection is about protecting you from leaks in underground steel tanks and piping.
How it Works
there are two types of cathodic protection – a passive system using sacrificial anodes and an active system using impressed current.
In both cases the principle involves making the component to be protected the cathode in a low voltage – generally less than the 1 volt (1000 millivolts) circuit. The cathode in the current receives electrons and does not deteriorate while the anode contributes electrons.
A passive system operates by connecting a “less noble” metal than the underground steel component to the system and this less noble metal, typically zinc or magnesium sacrifices itself and corrodes instead of the metal. Sacrificial anodes must must be inspected periodically depending on soil and moisture conditions.
An active impressed current system uses a direct current rectifier to apply the necessary voltage between a permanent anode and the components to be protected. Impressed current systems is somewhat more complex, requires higher maintenance and must be maintained to ensure it does not affect other metallic structures in the area.
The Technical Standards and Safety Authority (TSSA) requires that all underground steel components of a fuel system be equipped with cathodic protection. Cathodic protection must be inspected every 2 years whether the system is operational or not.
Comco is able to design a protection system for any application. Comco cathodic protection specialists are TSSA certified to inspect and install any cathodic system. Our staff have years of experience designing, installing cathodic protection and are continuously updated on regulatory requirements.