Corrosion on metal valves means that metal materials used for valves are destroyed under chemical or electrochemical environment. 

 

As is known to all, corrosion on metal has great impact on reliability and service life of valves. Mechanism and corrosion on metal increase total abrasion on contact surface. In terms of valves, the working environments are quite complicated. Hydrogen sulfide, carbon dioxide contained in oil, gas and oil reservoir water and some organic acids intensify destructive power on surface of metal, so metals valves lose service ability rapidly. 

 

Chemical corrosion on metal depends on temperature, mechanical loads on wearing components, sulfides contained in lubricating materials and stability for acid resistance. For this, corrosion resistance on metal valves and application of valves made of synthetic materials become one of the subjects in valve industry. 

 

Corrosion resistance of metal valves can be treated as that protective lever (such as lacquers, pigments and lubrication materials) is coated on the surface of metal valves to protect valves from being corroded. Nevertheless, the valves cannot be corroded during manufacturing, storage, transportation or utilization. 

 

Corrosion preventions of metal valves rely on protection duration, transportation and storage, features of valves and materials. So, economics of corrosion preventions also should be taken into consideration.  

 

The followings are corrosion preventions used for metal valves and their parts:

1. Highly volatile corrosion inhibitors are put into steam;

2. Use water and alcohol solution having been inhabited;

3. Corrosion prevention materials layer is coated on the surface of valves and their parts;

4. Film having been inhabited or layer of polymer is coated on the surface of valves and components.