What is the primary method of preventing corrosion of the interior of metal tanks?

The primary method of preventing corrosion of the interior of metal tanks is through cathodic protection. This method involves using a sacrificial anode or impressed current to protect the metal structure from corrosion. In a water storage tank, the metal can corrode due to electrochemical reactions, especially when in contact with water and other environmental factors.

Cathodic protection works by redirecting the corrosion process from the metal tank to another more easily corroded material (the sacrificial anode), thereby safeguarding the tank's interior. By maintaining a negative electrical charge on the tank, it minimizes corrosion rates and extends the life of the metal structure.

Other methods such as chemical coating, galvanization, and anodizing can also be effective for corrosion prevention. However, cathodic protection is particularly suited for large, water-filled metal tanks, where the environment can accelerate the corrosive process, making it the preferred choice in these applications.