Which component is classified as the anode in cathodic protection for sewer pipes?

In cathodic protection systems, specifically for sewer pipes, the sacrificial metal serves as the anode. This component is intentionally installed to prevent corrosion of the piping.

When a sacrificial anode is used, it is typically made of a more electrically active metal, such as zinc or magnesium. These metals corrode preferentially instead of the metal of the sewer pipes. By sacrificing themselves, they generate a flow of electrical current that helps to protect the cathode, which in this case is the sewer pipe itself.

This mechanism is effective because it creates an electrochemical reaction that reduces the overall corrosion rate of the pipe materials. By understanding the role of the sacrificial metal within this system, it becomes evident why it is classified as the anode: it plays a critical role in protecting the structure against the damaging effects of corrosion.