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The points of contact of sacrificial anodes with the protected structures are often the most critical areas of the cathodic protection systems. Using insulation gaskets is necessary for preventing aggressive media penetration to these points. However, in many cases, especially, when the anodes are not provided with carbon steel rods or strips for their mounting on the protected structure, introducing of an insulation gasket between the anode and the structure is impossible, since it breaks the electric contact anode-structure. Applying special conductive rubber gaskets (CRG) is the best solution for such systems.
There are many types of conductive rubber. Most reliable CRG presents scores of thin metallic wires that are embedded in an elastomeric material. Thus, when the gasket is pressed between the surfaces of a protected structure and a sacrificial anode, the thin wires provide a reliable electric contact between them. At the same time, the rubber provides a reliable prevention from aggressive environment penetration to the points of contact.
Along with increasing the reliability of the contact anode–structure, using of the CRG widens the possibilities of cathodic protection. Dual Mg-Al and Mg-Zn anodes with CRG may be successfully used for rapid polarization of protected structures at the initial stage of their protection that may be most promising for cathodic protection of rigs and platforms in the areas of deep water.
Using CRG in combination with resistors makes it possible to regulate the consumption rate of Mg anodes and in this way to increase the lifetime of Mg anodes and to prevent overprotection of aluminum while these metal structures are protected by Mg anodes
