Zinc rod/zinc plate

Scope of application: water pipelines, natural gas pipelines, petroleum pipelines, and city gas pipelines can also be used for cathodic protection of steel structures in fresh water.

In the natural environment, water, oxygen, acid-base mineral salts and microorganisms in the soil cause corrosion of metal pipes. The main function of pipe coating is physical barrier, which separates the metal matrix from the external environment, thereby avoiding metal and The surrounding environment, but there are two reasons that can cause metal corrosion. One is the inevitable defects of the coating itself, and the existence of pinholes; the other is that the coating will inevitably be destroyed during construction and operation, causing Metal is exposed to a corrosive environment. The existence of these defects leads to the phenomenon of large cathodes and small anodes, which greatly accelerates the corrosion of the damaged parts of the coating. Corrosion and perforation of the pipeline will occur, resulting in safety accidents. Years of practice at home and abroad have proven that the most effective corrosion The control measure is the combined protection of coating and cathodic protection.

There are two methods of cathodic protection: sacrificial anode cathodic protection and impressed current cathodic protection.

Sacrificial anode cathodic protection>>>
Sacrificial anode cathodic protection is to connect a metal with a more negative potential to the protected metal, and in the same electrolyte, so that the electrons on the metal are transferred to the protected metal, so that the entire protected metal is in one More negative at the same potential. This method is simple and easy to implement, does not require an external power supply, and rarely produces corrosion interference. It is widely used to protect small metal structures (current generally less than 1 ampere) or in low soil resistivity environments (soil resistivity less than 100 ohm•m). . For example, when designing a sacrificial anode cathodic protection system for urban pipe networks, small storage tanks, etc., in addition to strictly controlling the anode composition, it is necessary to choose an anode bed position with low soil resistivity.