Principle and scope of application of vacuum baffle valve of PVD coating machine: The working principle of vacuum baffle valve is that the valve plate is sealed by the up and down movement of the valve stem. There are three ways to drive the valve stem to move the transmission parts: manual, flashlight, and pneumatic. The manual transmission parts are mainly threaded structure, and flat cam structure can also be adopted.

        The manual transmission part is composed of electric actuator, worm gear and worm, and is equipped with a travel switch. , When the power is turned on, the motor rotates in a certain direction (such as the opening direction), and the valve stem is moved upward through the worm gear and worm to make the valve plate rise. When the valve plate rises to a certain height, the travel switch automatically cuts off the power. The valve stem movement stops immediately, and vice versa. During manual operation, loosen the cap on the back of the handwheel and turn the handwheel in a certain direction by hand. Figure 3 shows the outline drawing of the GDD type manual and electric vacuum baffle valve. Pneumatic transmission components use compressed air as power, change the direction of the air path through the electromagnetic reversing valve, push the cylinder piston up and down, drive the valve stem to move up and down, open and close the valve plate, so as to achieve the purpose of connecting or stopping the air flow.
       There are two types of vacuum flapper valves: high vacuum flapper valves and ultra-high vacuum flapper valves. The high vacuum flapper valve is used to connect or cut off the air flow in the high vacuum system. Applicable pressure range: 105～1.3×10-4Pa when the shaft seal is rubber; 105～1.3×10-5Pa when the shaft seal is a bellows structure. Working medium temperature: -25～80℃ (seal is nitrile rubber); -30～150℃ (seal is fluorine rubber). Body material: carbon steel nickel-plated or stainless steel; valve plate sealing material T-nitrile rubber or fluorine rubber. The ultra-high vacuum flapper valve is used to connect or cut off the air flow in the ultra-high vacuum system. The applicable pressure range is 105～1.3×10-8Pa and other valve open state, the baking temperature is less than 400℃, the valve body material is stainless steel; the valve plate material is oxygen-free copper; the seal material at the shaft seal is stainless steel bellows. : The working medium used by these two vacuum flapper valves is clean air or clean gas that does not corrode the valve. It is not suitable for long-term use under conditions of strong corrosion to metals and gas containing particulate dust.
       The high vacuum baffle valve has the characteristics of reliable sealing, large flow conductance, good safety, manual control, electric control, and air control. It has various forms, complete specifications, 150-120mm diameter and reasonable structure. Therefore, it is Widely used in vacuum systems of large and medium-sized high vacuum devices, such as PVD coating machines, vacuum heat treatment furnaces, vacuum brazing, high vacuum electron beam welding machines, ion beam etching equipment, space ring die equipment, etc. .