A sacrificial anode is a metal that has a more negative potential with respect to the structure metal to be protected. Sacrificial anodes corrode preferentially to the protected structure, providing protection to the structure.
The objective of a galvanic anode system is to deliver sufficient current to protect part of the structure for the designed life of the system. Sacrificial anode materials are usually alloys of aluminum, zinc, or magnesium.
There are three basic components of a marine sacrificial anode cathodic protection system (SACP):
1.Anode(s)
2.Connecting System, including cabling and fasteners
3.Protected Structure
Protected structures in ships include but are not limited to: ship hull, shafts, rudders, sea chests, heat exchangers, condensers, ballast tanks, etc.
