10-20Nm³/H Oxygen Generator,Oxygen Generator,20Nm3/H Oxygen Generator,High Efficiency Oxygen Generator Jiangsu Minnuo Group Co.,Ltd , https://www.mingngroupcn.com
Corrosion of the metal needle valve
Corrosion of needle valves is generally understood as the destruction of the needle valve metal material under the effect of a chemical or electrochemical environment. Since "corrosion" occurs in the spontaneous interaction between metal and the surrounding environment, how to separate the metal from the surrounding environment or use more non-metallic synthetic materials is the key point of anti-corrosion. Needle valve body (including valve cover), accounting for most of the weight of the valve, but also in regular contact with the medium, so the choice of valve, often starting from the valve body material. Valve body corrosion no more than two forms, namely chemical corrosion and electrochemical corrosion. Its corrosion rate depends on the medium temperature, pressure, chemical properties and corrosion resistance of the valve body material. Corrosion rate can be divided into six grades: 1, Corrosion resistance: Corrosion rate lower than 0.001 mm / year; 2, Corrosion resistance: corrosion rate of 0.001 to 0.01 mm / year; 3, Corrosion: corrosion rate of 0.01 to 0.1 mm / Year; 4, still corrosion: corrosion rate of 0.1 to 1.0 mm / year; 5, poor corrosion resistance: corrosion rate of 1.0 to 10 mm / year; 6, corrosion resistance: corrosion rate greater than 10 mm / year.