MMO coated titanium anodes for cathodic protection: Fid-Bau Portal

MMO coated titanium anodes for cathodic protection

Kroon, David H.

Not all mixed metal oxide (MMO) coated titanium anodes are the same. MMO coatings have different compositions, some of which perform better for specific applications. Certain environments can cause increased wear rates or anode fouling. The performance of iridium oxide and ruthenium oxide coatings are compared. In addition to the coating, preparation of the titanium substrate, application of the coating, lead wire insulation, electrical connection and quality control procedures have substantial impact on anode performance and life. Case histories for underground conventional and concrete cathodic protection applications are included. Mixed metal oxide coated titanium electrodes have become the anode of choice for many impressed current cathodic protection applications. Case histories clearly demonstrate that MMO anodes will meet all performance objectives. To ensure MMO anode performance which satisfies system design criteria, it is important that: The anode is supplied with the optimum MMO coating for the application. The MMO coating is properly applied, with the necessary process control and quality control procedures to assure optimum performance. The electrical connection to the anode is very low resistance and positively sealed from moisture. The lead wire insulation is resistant to attack from gases that evolve as a result of the oxidation reactions at the anode surface.