Impressed Current Protection Anodes, (sometimes known as Impressed Current Cathodic Protection (ICCP) are a method of sacrificial protection that does not require that the anode be more ‘active’ than the metal structure to be protected. These type of anodes are mainly used for larger structures, or where electrolyte resistivity is high and galvanic (sacrificial) anodes cannot economically deliver enough current to provide protection. Impressed current protection anodes use an electrical support in the form of a controlled amount of direct current connected between the anode and the structure, where the positive part of the circuit is connected to the anode and the negative part to the structure.
Professionals state that Impressed Current Protection Anodes are the ultimate cutting edge long term solution to corrosion problems and are highly recognised as superior alternative to sacrificial anode systems. Before the electrochemical action of galvanic corrosion even has time to begin the system constantly regulates and monitors the electrical current to prevent this from happening. Specialist Castings offer 2 types of high quality and reliable Impressed Current Protection Anodes; MMO Anodes and Silicon Iron Anodes. We have over 30 years experience manufacturing anodes, therefore we guarantee durability and quality in all of our products.
How do impressed current protection anodes work?
Impressed current protection anodes work by having a direct current connected between the anode and the structure to be protected. These anodes can be made of various materials, including cast iron, mixed metal oxide or graphite and the anode itself can come in many shapes and sizes, such as sticks, plates or wires.
The anode is installed within the electrolyte around the structure to be protected and connected to the positive output, while the structure is connected to the negative terminal. The current flows from the anodes, through the electrolyte and onto the structure, with the metallic connection between the structure and the rectifier completing the DC circuit. The size of the electrical current is regulated by a sensor which is connected to the structure and increases in line with the hostility of the environment the structure is placed in.
Electrical resistance within the circuit is important and should be kept below 0.10 ohms. To this end connections should ideally be welded, or brazed to clean surfaces. That is, with any oxidisation coating removed.