Selection of Protective Coating System for Tank Inner Surface

Abstract

Inner surface of tanks is subject to corrosion due to constant contact with aggressive medium. The greatest danger from the point of view of possible corrosion destruction of steel is water (bottom, lower belts of the tank) and gas-air mixture (roof, upper belt) due to saturation with aggressive components: hydrogen sulfide, carbon dioxide, salts. Failure statistics show that the main reason for the failure of oil tanks (about 70%) is the corrosive wear of the surface that comes into contact with the aggressive medium. The application of paint coatings on the internal surfaces of steel tanks for the storage of oil and oil products is an effective measure to reduce corrosion and increase the life of tanks. However, there are a great many coatings. From the experience of tank operation, paint coatings of the following types were selected to analyze the effectiveness of corrosion protection: XC-717, EP-0020, FL-777, VN-780. To select the paint coating of the inner surface of the tank, physical and mechanical parameters were determined and calculations of the corrosion rate of the tank walls for the above paint coatings were carried out. After physical and mechanical tests, it was established that the best values of the coating are EP-0020. Thus, it is recommended to use a EP-0020 coating as a passive protection of the inner surface to ensure the durability of the tanks.