Cathodic protection systems main

Cathodic Protection

Churchill specialise in the design and installation of both Galvanic and Impressed current cathodic protection systems.

In the application of passive cathodic protection, a galvanic anode is attached to the vulnerable metal surface where it is exposed to an electrolyte. Galvanic anodes are selected because they have a more "active" voltage than the metal of the target structure (typically steel).For effective cathodic protection, the potential of the steel surface is polarized (pushed) more negative until the surface has a uniform potential. At that stage, the driving force for the corrosion reaction with the protected surface is removed. The sacrificial galvanic anode will corrode and not the embedded steel reinforcement

For larger structures, or where electrolyte resistivity is high, galvanic anodes cannot economically deliver enough current to provide protection. In these cases, impressed current cathodic protection (ICCP) systems are used. These consist of anodes connected to a DC power source, often a transformer-rectifier connected to AC power.

ICCP systems are typically used on larger structures such as bridges, jetties or on essential infrastructure where long term protection is paramount.

Working closely with our level 3 ICCP design engineer, Churchill are able to provide bespoke cost effective cathodic protection systems

Case Study: Penarth Pier / Sea Wall. Sika XP2 Galvanic Anodes

Cathodic protection system 1
Cathodic protection system 2