As we all know, the corrosion damage of metal has a considerable impact on the service life and reliability of the valve. The influence of mechanical and corrosive factors on metals greatly increases the total wear of the contact surfaces. The total amount of wear on the friction surfaces of the valve during operation. During valve operation, friction surfaces can wear and be damaged due to simultaneous mechanical and chemical or electrochemical interactions between the metal and the environment. For the valve, the climatic conditions of its pipeline work are complex; the presence of hydrogen sulfide, carbon dioxide and some organic acids in oil, natural gas and reservoir water increases the destructive power of its metal surface, resulting in a rapid loss of working ability.
Valve corrosion is generally understood as the damage of valve metal materials under the action of chemical or electrochemical environment. Since corrosion occurs in the spontaneous interaction of metals with the surrounding environment, how to isolate the metal from the surrounding environment or use more non-metallic composite materials has become a common concern.
Because the chemical corrosion of metals depends on the temperature, the mechanical load of the friction parts, the sulfides contained in the lubricating material and their acid stability, the contact time of the medium, the catalytic effect of the metal on the nitriding process, the conversion of the corrosive substance molecules to the metal Therefore, the anti-corrosion methods (or measures) of metal valves and the application of synthetic valves have become one of the research topics in the valve industry.
The anticorrosion of metal valves can be understood as the coating of conditional protective layers (such as paints, pigments, lubricating materials, etc.) on metal valves to protect them from corrosion, so that the valve can be used in the whole process of manufacturing, storage, transportation or use. not corroded. The method of corrosion protection for metal valves depends on the required protection period, transport and storage conditions, valve construction characteristics and materials. Of course, the economics of removing the coating should be considered.
There are four main anti-corrosion methods for metal valves and their parts:
1. Put the volatile corrosion inhibitor into the steam environment (wrap it with inhibitor paper, blow the inhibitor air into the product room, etc.).
2. Use inhibitory water and alcohol solutions.
3. Coat the surface of the valve and its parts with a thin layer of anti-corrosion (protection) material.
4. Apply an inhibitory film or a thin layer of polymer on the surface of the valve and its parts.