Vacuum valve used in electronic industry
Vacuum valve used in electronic industry
The valve in the vacuum device is used to separate the parts of the system. According to their working characteristics, they can be divided into pre vacuum valve and high vacuum valve. The diameter of the inlet and outlet of the former is generally about 15-20 mm, which is mostly sealed with vacuum rubber gasket, which is used for the pre vacuum part. The diameter of the latter is 65, 100, 150, 180 mm or more. Metal gasket is used for sealing (especially for valves in ultra-high vacuum part). Only when the limit vacuum is less than 10-6 Torr, rubber seal is used more. They are widely used in the use of materials, brass, steel, stainless steel and other metals, because of the porous casting, so vacuum valves are not casting.
For the valve stem and cover or with the valve body of the main form of sealing, rubber, metal corrugated pipe, film (refers to the valve made of bronze or nickel skin, thickness of 0.1-0.15 mm corrugated film seal, generally its reciprocating *** of 2-4 mm) is less used.
In the valve hole sealing (refers to the sealing of the closing valve), generally using vacuum rubber. The conical valve disc (made of soft material silver, nickel or brass) and the cylindrical seat (made of quenched steel) is tightly sealed in linear form. Due to its poor durability (such as the valve disc is slightly skewed to the seat, the sealing surface processing is defective, and the valve seat is pressed too tightly, the valve is no longer tight and needs to be repaired). It is only used in ultra-high vacuum. Oil seal and liquid metal seal are not widely used except for some systems with high vacuum requirement and small pipe size.