How to distinguish the corrosion resistance level of sanitary butterfly valve?

The corrosion resistance grades of sanitary butterfly valves are also distinguished, so how to distinguish the corrosion resistance grades of sanitary butterfly valves? Here we take a look! Corrosion of sanitary butterfly valve is usually understood as the damage to the metal material of sanitary butterfly valve under the action of chemical or electrochemical environment. Since the phenomenon of "corrosion" occurs in the spontaneous interaction between metal and the surrounding environment, how to isolate the metal from the surrounding environment or use more non-metallic composite materials is the focus of anti-corrosion.

   The valve body (including the bonnet) of the sanitary butterfly valve occupies most of the weight of the sanitary butterfly valve, and is in frequent contact with the medium, so the selection of sanitary butterfly valve often starts from the valve body material.

    There are only two forms of corrosion of the valve body, namely chemical corrosion and electrochemical corrosion. Its corrosion rate depends on the temperature, pressure, chemical properties of the medium and the corrosion resistance of the valve body material. The corrosion rate can be divided into six grades.

    The anti-corrosion of the valve body mainly depends on the correct selection of materials. Although the anti-corrosion information is very rich, it is not easy to choose the right one, because the problem of corrosion is very complicated. For example, sulfuric acid is very corrosive to steel when the concentration is low. Passivation film, can prevent corrosion; hydrogen only shows strong corrosiveness to steel under high temperature and high pressure, chlorine gas is not very corrosive when it is in a dry state, and has strong corrosiveness when there is a certain humidity, many materials can not be used . The difficulty in choosing valve body materials is that not only the corrosion problem, but also the pressure and temperature resistance capability, whether it is economically reasonable, and whether it is easy to purchase must be considered. So you have to be careful. The above is an introduction to the corrosion resistance level of sanitary butterfly valves.