What is the difference between a disc welded metal bellows v

Writer： admin Time：2021-10-14 22:44 Browse：℃

What is the difference between a disc welded metal bellows vacuum valve and an ordinary valve? Vacuum valve refers to the vacuum state of the inner cavity of the valve, usually called negative pressure, and the inner cavity pressure is lower than atmospheric pressure. Valves used in vacuum piping systems include vacuum ball valves, vacuum butterfly valves, and vacuum diaphragm valves. The medium is high purity. Ball valves, gate valves, globe valves, etc. can all be produced into vacuum valves and ordinary conventional valves. There is no difference in appearance, and there is a difference in the design of the valve connection part, but it is only a matter of detail. Compared with the positive pressure valve, the vacuum valve has the following characteristics: the pressure is lower than the atmospheric pressure, and the pressure drop on the valve disc cannot exceed 1 kgf/cm2. The working temperature of the medium depends on the process of using the device. The temperature generally does not exceed the range of -70 ~ +150℃. The basic requirement for this type of valve is to ensure a high degree of sealing of the connection and the compactness of the structure and gasket material. According to the medium pressure, vacuum valves can be divided into four groups: 1) Low vacuum valve: medium pressure p=760~1 mmHg; 2) Medium vacuum valve: p=1×10-3 mmHg. 3) High vacuum valve: p=1×10-4 ~1×10-7 mmHg; 4) Ultra-high vacuum valve: p≤1×10-8 mmHg. Vacuum bellows globe valve with valve stem that moves linearly, which is widely used in vacuum valve. Gate valves are subject to greater restrictions, but for large diameters, ball valves, plunger valves and butterfly valves are also available."