Standard Specification for Anodes, Sacrificial Zinc Alloy

This specification covers the requirements for sacrificial anodes of zinc alloy in the form of slabs, plates, discs, and rods for corrosion protection (cathodic protection) of metals and alloys. These anodes are primarily intended to reduce corrosion of surface ship and submarine hulls, steel and aluminum equipment and structures, sea chests, sonar domes, and the seawater side of condensers and other heat exchangers. The anodes are available either as cast-in cores (Class 1) or plain with no cores (Class 2). Class 1 anodes shall be of the following types: Type ZHS—hull slabs with steel straps; Type ZHB—hull slabs with brass straps; Type ZHC—hull slabs with core straps; Type ZSS—submarine slabs with steel straps; Type ZTS—teardrop shapes with steel straps; Type ZEP—heat exchanger or fair water discs (pipe core or pipe bushing core) that are in the form of square slabs (Style A), circular slabs (Style B), and semicircular slabs (Style C); Type ZBP—bars with pipe cores; and Type ZDM—segmented discs with machine formed interlocking cores. Conversely, Class 2 anodes shall be of the following types: Type ZRN—extruded, drawn or rolled rods; and Type ZPN—rolled plates. Anodes shall conform to material and manufacture, chemical composition, mechanical property, and dimensional requirements specified uniquely for each type.