Research On Technique Of Cathodic Protection

According to on site leakage on the oil storage tank, through research on cathodic protection technique, using appropriate cathodic protection measures, setting exact parameters to optimize the cathodic protection design. The cathodic protection technique for oil tank is fully developed. It can realize low cost and good protection effect as long as properly choose and control related parameters during design and operation process; at the same time, strictly control the quality of raw material and apparatus. It is not only benefit to the economic, but also to the society. Normally cathodic protection is acquired by sacrificial anodes or impressed current. Both methods have pros and cons. In different occasion, compare these methods and choose the better. While compare the methods, the following factors shall be taken into consideration: the surface layer protection situation of the tank, environment, power supply and economical benefit. If adopt cathodic protection method both on the inner and the outer surface of the tank, it can make up the insufficient coating by polarization the omission surface, and greatly reduce the corrosion. Thus, using cathodic protection and coating method together can realize the best tank protective effect. Through research on cathodic protection method, according to different using condition, combine with the on site testing effect, select appropriate cathodic protection method and solve problems. Analyses the corrosion area of the tank, find the influence factors as per the analysis to different areas, and decide the feasibility of cathodic protection method.. The most important is to confirm current density, material and type of sacrificial anodes, and the material and lifespan of anodes, As the corrosion area of coating increases, the current density shall increase accordingly. While determine the current density, take the lifespan of cathodic protector into consideration. As for the sacrificial anodes method, anodes are evenly distributed around the old tank, and are evenly under the new tank. Because the pipe in the casing is very difficult to repair and replace , we use sacrificial anodes method inside the casing for new pipe design. It makes a combination system of protection layer and cathodic protection inside the casing.