The characteristics and selection of vacuum valve according to the introduction

The vacuum valve is a component used in the vacuum system to regulate the gas flow, cut off and close the pipeline. According to its working principle, it is mainly divided into a vacuum butterfly valve, a vacuum diaphragm valve, a vacuum flapper valve, a vacuum ball valve, a vacuum solenoid valve and the like.

    The vacuum valve has the following characteristics: the working pressure is lower than atmospheric pressure. The operating temperature of the media depends on the process in which the device is used. Half of the temperature does not exceed the range of -70 to +150 °C.

    The most basic requirement for such valves is to ensure a high degree of sealing of the joint and the compactness of the gasket material of the domain.

Vacuum valves can be divided into four groups according to the medium pressure:

    1 low vacuum valve: medium pressure P = 760 ~ 1 mm Hg;

    2 medium vacuum valve: P = 1X10-3 mm Hg;

    3 high vacuum valve: P = 1X10-4 ~ 1X10-7 mm Hg;

The selection of vacuum valves is based on the following points:

    1. According to the working pressure, there are low vacuum valves, high vacuum valves and ultra high vacuum valves;

    2. According to the structural characteristics, there are vacuum butterfly valve, vacuum ball valve, vacuum diaphragm valve, vacuum flapper valve, vacuum flapper valve, vacuum angle valve, vacuum straight-through valve, vacuum three-way valve, etc.

    3. According to the transmission principle, there are manual, pneumatic, electric and electromagnetic. Generally, the pneumatic process is an electromagnetic pilot and a cylinder performs an action, and the process of performing the action of the pilot valve cylinder can also be controlled by hand. Electric for both hands and electricity, when the power is off, you can use manual operation.

    4. According to the material, the valve contains stainless steel, carbon steel and aluminum alloy as the main material.

    5, according to the sealing material of the vacuum valve can be divided into metal sealed or non-metallic sealed valve. The O-ring rubber ring for the shaft seal generally has a leakage rate of 10-4 Pa.L/S for the vacuum dynamic seal. The vacuum is not high during the shaft movement, and can be used under the vacuum condition where the requirement is not high; the shaft seal is a bellows seal. The leak rate is 10-7Pa.L/S, which is suitable for use under ultra-high vacuum conditions.