Brief Introduction of Vacuum Valve
To select the model and specification of the valve correctly, we need to know the preparation method of the vacuum valve model; the preparation method of the vacuum valve model of our company is basically similar to zbj78016-89 “vacuum valve model and preparation method”. The product model is composed of basic model and auxiliary model, separated by short horizontal lines. The model composition is as follows:
Represents the range of vacuum degree used by the product, which is represented by the first letter (block capital) of its keyword Chinese Pinyin
- The range of representative vacuum degree is: for low vacuum 105 ~ 10-1pa (760 ~ 10torr) – D;
- Representative vacuum range: G for high vacuum 105 ~ 10-4Pa (760 ~ 10-6 Torr);
- The range of representative vacuum degree is: for ultra-high vacuum 10-10-7pa (760-10-9 Torr) – C;
It represents the structural form of valve plate or product functional category, which is represented by the first (or second) letter (in block capitals) of Chinese Pinyin as follows:
C plug valve, Q charging valve, D baffle valve, u ball valve, f flap valve, w fine adjustment valve, I butterfly valve, y differential pressure valve, m diaphragm valve;
Represents the product driving mode, which is represented by the first letter of Chinese Pinyin (printed capital):
S manual, D electric, Q pneumatic, C magnetic, y hydraulic;
Represents the form of valve channel, represented by the first letter of Chinese Pinyin (printed capital):
Z through valve, J angle valve and s three-way valve;
Special case: only valves with inflation are coded with capital letter Q in Chinese Pinyin, and other types of valves are not.
Represents the product specification parameter – nominal diameter, expressed in Arabic numerals, in mm:
For example: DN 16mm, 100mm, 500mm, etc. are represented by 16100500, etc.
Special case: “30” in the model of gw-30-t high vacuum fine tuning valve indicates that the maximum adjustable value of high vacuum fine tuning valve is 30 Torr. L / s.
The angle note represents the seal structure of shaft seal. At present, only stainless steel bellows are used as the seal, and the Chinese Pinyin small letter B is used as the code. Other seal structures (such as rubber seal, polytetrafluoroethylene, etc.) are not represented by letters.
Only individual products (such as vacuum (pressure) ball valves) use capital letters with brackets to indicate the connection mode or the code of main sealing materials of valves.
(KF) refers to gb4982 clamping vacuum quick release flange standard, (g) refers to gb7306 cylindrical pipe thread standard, (f) refers to gb6070 looper vacuum flange standard, (JB) refers to jb919-75 vacuum flange standard h or H (I) refers to the welding structure of the interface at both ends of the valve, H (II) It means that one end of the valve is welded and the other end is rubber pipe;
The products designed for the first time are as follows:
- Gm-25h (I) high vacuum diaphragm valve, nominal diameter 25 mm, welded structure at both ends.
- Ccq-150 pneumatic ultra-high vacuum gate valve, nominal diameter of 150 mm.
- Gid-250 electric high vacuum butterfly valve, nominal diameter 250mm.
- Guq-40 (KF) pneumatic high vacuum (pressure) ball valve, nominal diameter 40mm, connection method is gb4982 clamping vacuum quick release flange Dn40 quick release flange.
- Gd-j100b high vacuum flapper valve, nominal diameter of 100mm, conduction form of angle type, shaft seal form of stainless steel metal bellows.
- Dyc-jq50 electromagnetic vacuum differential pressure valve, nominal diameter: 50mm, conduction type: angle type. (low vacuum generally only needs two words of vacuum).
- Ddc-jq80 electromagnetic vacuum with inflation valve, nominal diameter 80mm, conduction form is angle type. (low vacuum generally only needs two words of vacuum).
- Gdc-j25b electromagnetic high vacuum flapper valve, nominal diameter 25mm, conduction form is angle type. The shaft seal is made of stainless steel metal bellows.
The vacuum valve has the following characteristics:
The pressure is lower than atmospheric pressure, and the pressure drop on the 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 to + 150 ℃.
The most basic requirement for this kind of valve is to ensure the high tightness of the connection and the compactness of the structure and gasket material.
According to the medium pressure vacuum valve can be divided into four groups:
1) Low vacuum valve: medium pressure P = 760 ~ 1mm Hg
2) Medium vacuum valve: P = 1 × 10-3 mm Hg.
3) High vacuum valve: P = 1 × 10-4 ~ 1 × 10-7 mm Hg
4) Ultra high vacuum valve: P ≤ 1 × 10-8 mm Hg.
As a closed-circuit valve with a diameter less than 250mm, the widely used valve stem is a vacuum bellows stop valve with a linear motion. Gate valves are subject to greater restrictions, but this is mainly for large diameters. Also available are ball cock (ball valve), plunger valve and butterfly valve. The plug valve used as a vacuum valve has not been popularized because the plug valve needs to be lubricated with oil so that oil vapor may enter the vacuum system, which is not allowed. The vacuum valve can be controlled by hand and remote control on site, as well as electric, electromagnetic drive (solenoid valve), pneumatic and hydraulic control.
