Implementation - internal surfaces in contact with liquid

The most used anodes for cathodic protection of “internal surfaces” under impressed current are: ferro-silicon, graphite, conductive polymers, coating made of platinum or oxides of titanium or another noble metal, sometimes aluminium or iron.

The galvanic anodes for fresh water are made of magnesium alloy, whereas in sea water they are made of zinc or aluminium.

Chart 3 : Requirements about internal surfaces under cathodic protection, with a risk of hydrogen emission