With the advancement of skills, industrial production of high-parameter high temperature, high pressure, deep cold, high vacuum, strong corrosion, radioactivity, flammable and explosive and other high-parameter messy working conditions are increasing. Higher and more stringent requirements have been put forward in aspects such as life span.
Because the "corrosion" phenomenon occurs in the spontaneous interaction of metal with the surrounding environment, how to isolate the metal from the surrounding environment or use non-metallic synthetic materials is the focus of anti-corrosion. Valve corrosion is generally understood as the damage to valve metal materials under the influence of chemical or electrochemical environment.
There are two forms of valve body corrosion, namely chemical corrosion and electrochemical corrosion. Its corrosion rate is determined by 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 categories:
1. Complete corrosion resistance: the corrosion rate is lower than 0.001 mm / year;
2. Extremely corrosion-resistant: the corrosion rate is 0.001 to 0.01 mm / year;
3. Corrosion resistance: The corrosion rate is 0.01 to 0.1 mm / year;
4. Corrosion resistance: the corrosion rate is 0.1 to 1.0 mm / year;
5, poor corrosion resistance: corrosion rate of 1.0 to 10 mm / year;
6. Non-corrosion resistance: The corrosion rate is greater than 10 mm / year.
Although there is a wealth of information on valve body corrosion prevention, it is still not easy to choose it properly, because the problem of corrosion is very complicated. So, what are the protection methods for valve body corrosion?
First, choose the right materials. The difficulty in selecting the material of the valve body lies in the fact that not only the corrosion problem can be considered, but also the pressure and temperature resistance, whether it is economically reasonable, and whether it is easy to purchase and so on.
Followed by lining measures, such as lead lining, aluminum lining, engineering plastics, natural rubber and various synthetic rubber. If the media conditions permit, this is a way to save.
Thirdly, when the pressure and temperature are not high, using non-metals as the main material of the valve can often prevent corrosion very effectively.
In addition, the outer surface of the valve body is also corroded by the atmosphere. Generally, steel materials are protected by painting.
Address: 283 Weiyang Road, Yangzhou City, Jiangsu Province
Copyright © Copyright: Yangzhou Kaidesi Environmental Protection Equipment Co., Ltd. 苏 ICP 备 19005859 号