Specialist Castings have over 30 years experience in manufacturing and supplying anodes for cathodic protection.  Our range of anodes includes various specifications of both impressed current protection and sacrificial anodes.

We produce an extensive range of standard anodes and have the ability to produce non-standard items to exact specifications.

All of our anodes are produced according to the strictest quality and traceability guidelines and international standards. Whether to ASTM standards, British standards, European standards or International standards, the foundry manufactures to these standards and also carries out testing to these International standards. Whether it is chemical certificates from NAMAS approved testing laboratories, or G97 accelerated corrosion tests from USA laboratories or X-ray testing of anodes to ASTM E184 or other criteria, we ensure we operate at the highest quality levels required of the worldwide marketplace. We are currently, for instance, the only fully approved Chinese supplier of Magnesium anodes to Aramco and we have 4 spectrometers for silicon iron alone, as well as 2 spectrometers for Magnesium testing and we are still currently expanding these testing and inspection facilities.

We pride our selves on the quality of our products and adhere to strict processes throughout the production process, to ensure full transparency and traceability of our products.


What is Cathodic Protection?

Cathodic Protection is a method that is employed to limit or control the corrosion of a metal. In particular metal surfaces that are constantly exposed to highly corrosive environments, such as underground oil or gas pipes, or ships.

It is an electro-chemical method and works by making the metal to be protected the cathode of an electrochemical cell. The metal to be protected is forced to become “cathodic” in character by the anode that consequently becomes “anodic” in character, by the anode which consequently works by offering itself as “sacrificial metal”, thus defending the metal to be protected.   In short, the sacrificial metal (or anode) corrodes instead of the metal being protected.  There are two primary methods of cathodic protection; sacrificial protection and impressed current protection.

With sacrificial cathodic protection, polarisation of the structure to be protected (the cathode) is caused by the electron flow from the anode to the cathode, so the two metals must have a good electrically conductive contact. The driving force for the cathodic protection current is the difference in electrode potential between the anode and the cathode.  These systems are stand alone and do not require an additional electrical source. Types of sacrificial anodes include magnesium anodes, aluminium anodes, water box anodes and zinc ribbon anodes.

In an impressed current protection system, an external source of electric current is used to help drive the protective electrochemical reaction.

This type of approach is more often used for larger structures, or where electrolyte resistivity is high and galvanic anodes cannot economically deliver enough current to provide protection.  Anodes used in this type of cathodic protection include silicon iron anodes, mixed metal anodes and, occasionally, graphite to titanium anodes.  The most commonly used impressed current anodes are silicon iron tubular anodes, silicon iron solid (or stick anodes and MMO anodes.