Metal corrosion and protection method of pneumatic valve pneumatic body < / div >

corrosion of pneumatic valve, pneumatic valve is often understood as metal materials in the chemical or electrochemical environment under the action of the damage. As a result of 'corrosion' phenomena appeared in the metal and the surrounding environment of spontaneous interaction, how the metal with the surrounding environment or more isolated from the use of non-metallic composite material, is the key point of anti-corrosion. Pneumatic valve pneumatic valve body ( Including pneumatic valve cover) , make up most of the pneumatic valve weight, again in frequent contacts with the media, so choose pneumatic valves, often from pneumatic valve body material. Pneumatic valve body corrosion, comes in two forms, namely, chemical corrosion and electrochemical corrosion. The corrosion rate of it depends on the medium temperature, pressure, chemical properties and corrosion resistance of pneumatic valve body material. Corrosion velocity can be divided into six: 1, complete corrosion: corrosion speed below zero. 001 mm/year; 2, corrosion resistant, corrosion speed of 0. 001 to 0. 01 mm/year; 3, corrosion resistant, corrosion speed of 0. To 0 01. 1 mm/year; 4, it is corrosion resistant, corrosion speed of 0. 1 to 1. 0 mm/year; 1 5, poor corrosion resistance: the corrosion rate. 0 to 10 mm/year; 6, no corrosion, corrosion speed is greater than 10 mm/year. Pneumatic valve anti-corrosion, mainly is the right to choose material. Although anticorrosion materials is very rich, but can choose appropriate, or not easy thing, because the problem of corrosion is very complex, such as sulfuric acid at low concentrations to steel corrosion resistance, high concentration, make steel passivation membrane, corrosion resistance; To show only under high temperature and high pressure hydrogen corrosion of steel is very strong, chlorine gas in the dry state when corrosion is not large, with a certain humidity, strong corrosion performance of many materials can't use. Choose pneumatic valve body material difficulty, is not only considered corrosion problem, the pressure must be considered and heat-resistant ability at the same time, the economically reasonable, whether the purchase easy and other factors. So you have to is in the heart. Followed by lining measures, such as lining, lining aluminum, lead lining engineering plastics, lining natural rubber and various synthetic rubber, etc. Such as medium conditions permit, it is a way to save. Again, in the case of pressure, temperature is not high, made from non-metallic pneumatic valve body material, often can effectively control the corrosion. In addition, pneumatic valve body outer surface by atmospheric corrosion, steel materials are usually protection by paint.