There are 3 sizes of sacrificial anodes in zinc, magnesium, and aluminum alloys:


  • U.S.S.-12:  U.S.S.-12 anodes are 4 inches in diameter and 12 inches long. They are optimal for use in low resistivity environments and are recommended to be used for internal protection of tanks. The U.S.S.-12 versatility allows it to be used for external protection of structures in soil as well. Aluminum anodes are not applicable for soil environments.

  • U.S.S.-4:  U.S.S.-4 anodes are 6 inches in diameter and 4 inches long. They are designed to perform in soil and protect against external corrosion of structures. U.S.S.-4 can also be used for internal protection of tanks and vessels.

  • U.S.S.-2:  U.S.S.-2 anodes are 10 inches in diameter and 2 inches long. They are designed for installation in tanks and hulls for internal and external protection. The U.S.S.-2 larger diameter and shorter height provides a lower profile, easing the installation inside tanks and hulls.


All 3 types of anodes can be stacked together and secured with threaded joints to achieve the desired anode weight and surface area. This allows CP system designers to customize anode size and weights based on the needs of the system. To secure the anodes to vessel structures in liquid environments, threaded joints are welded onto the vessel surfaces. The anodes are then stacked onto glass-reinforced epoxy isolators to help prevent internal coating damage. The threaded joint welded to the vessel surface passes through the isolator and threads into the anodes.


The following charts illustrate the effects of adding additional segments of Multipurpose Segmented Sacrificial Anodes on surface area, height, weight, life, resistance, and current output on each available standard alloy.