Cathodic Protection

The principle of cathodic protection is in connecting an external anode to the metal surface to be protected and the passing of the ensuing electrical dc current so the metal surface becomes cathodic and therefore does not corrode.

There are two forms of anodic protection.

1) Galvanic Sacrificial Anodes

This form of ANODIC protection requires:

• A sacrificial anode
• These anodes are welded directly to the surface to be protected
• Minimum electrical resistance at the connection interface

2) Impressed Current

This form of ANODIC protection requires:

• Inert anodes
• DC power source
• Insulated connectors with minimum electrical resistance between the power source and anode
• Minimum electrical resistance in the connection between the power source and structure.