The basic characteristics of the valve of the PVD coating machine are high air tightness (reliable sealing); the resistance to airflow is as small as possible (that is, the conductance of the valve is as large as possible); the sealing parts have good wear resistance, can be used repeatedly, and have a long life. ; The valve body material and seals have a small amount of air release; flexible operation, easy to clean and install, reliable performance, and convenient maintenance. In addition, the ultra-high vacuum valve is required to be able to withstand high temperature baking (450℃); the throttle valve is required to be able to adjust the gas flow evenly.

       The materials of commonly used vacuum valve body are mainly metal and glass. The manual vacuum valve drive hand wheel is made of high-strength plastic material. The glass vacuum piston is also called "Cock" and is generally used in glass vacuum systems, small vacuum devices, vacuum gauges or calibration systems. The advantages are relatively easy to manufacture, convenient to use, easy to clean and observe, chemically stable and insulating, and less outgassing. The disadvantage is that the brittleness of the glass and the coating of grease on the elbow of the piston limit its scope of use. Vacuum devices required for industrial production, such as PVD coating machines, vacuum smelting equipment, vacuum heat treatment equipment, space environment simulation equipment, rocket engine simulation equipment, satellite surface charging simulation equipment, particle accelerators and controlled nuclear fusion devices, heavy particle accelerators, etc. All use metal valves.
       Vacuum valves of vacuum coating machines are usually classified according to their working characteristics, transmission principles, connection methods and uses, etc., and can be divided into the following categories:
       ①According to the working pressure: there are low vacuum valves, high vacuum valves, ultra-high vacuum valves;
       ②According to the purpose: there are stop valve, isolation valve, charging (discharging) valve, throttle valve+, reversing valve, closed feeding valve, etc.;
       ③According to the transmission principle: there are manual valves, dual-purpose valves with flashlights, solenoid valves, pneumatic valves, and hydraulic vacuum valves;
       ④According to the material: there are glass vacuum piston (Cock), metal vacuum valve;
       ⑤According to the structural characteristics: there are flapper valves, flap valves, butterfly valves, ball valves, connecting rod valves, diaphragm valves, gate valves, two-way valves, three-way valves, four-way valves, straight-way valves, right-angle valves, etc.
        The valve of the PVD coating machine is an important part of the PVD coating machine. Therefore, the customer pays special attention when purchasing equipment. Whether the valve is selected properly has a great relationship with the coating effect and life of the later PVD coating machine.