Cathodic protection of a metal can be performed by coupling the metal with a less noble material, called “galvanic anode” which will corrode instead of the interested main structure thereby preserving it over time (Sacrificial Anodes Cathodic Protection - SACP) or polarizing the metal with an external voltage source (Impressed Current Cathodic Protection systems – ICCP).
Sacrificial anodes have a long and successful application history; their use can be traced back to 1824 when Sir Humphry David protected copper sheathing of a warship using iron anodes.
Nowadays, use of sacrificial anodes have spread to many different application, and the material technology allowed the production of way more efficient anodic alloys targeted to increasingly specific applications.
Impressed current C.P. system have a more recent history, and overcome some of the limits of galvanic anodes: polarization of the structures to be protected is achieved using an external voltage source (Transformer/Rectifier) whose negative terminal is connected to the structure, while the positive terminal is connected to a series of earth electrodes (impressed current anodes) that delivers the electrical current necessary for the polarization.
More information on these solutions can be found in the relative section of our offer.