Cathodic protection construction of storage tanks

Regarding cathodic protection, the outer wall of the tank bottom plate must undergo cathodic protection, and the applicable cathodic protection methods vary depending on the environment and equipment size. For large storage tanks, especially when the soil resistivity is high, the cathodic protection method is external current cathodic protection; For small storage tanks and environments with low soil resistivity, the appropriate cathodic protection method should be sacrificial anode cathodic protection. Before selecting the cathodic protection mode, it is necessary to calculate the cathodic protection current. In this regard, it is necessary to consider that the grounding system of cathodic protection may result in a loss of cathodic protection current.

When making the foundation of the storage tank, it is often necessary to sprinkle a layer of asphalt sand on the cathodic protection system. It is not recommended to do so because it will hinder the current generated by the cathodic protection system from moving towards the bottom plate of the storage tank, which will affect the effectiveness of the cathodic protection system. So now most storage tanks are coated with a layer of primer on the outside of the tank bottom plate. Many people believe that the primer is easily damaged during the welding process and are worried. Actually, this is quite normal. Although the primer is easily damaged, only a small part of it is damaged, and most of it can still be well preserved. This will effectively reduce the current demand of the cathodic protection system, and the current distribution will be very uniform.