The Role and Classification of Vacuum Valves in Vacuum Systems
In the vacuum system, the vacuum valve is used to change the direction of air flow, adjust the size of the air flow, and cut or connect the vacuum system of the pipeline
The role of vacuum valve in vacuum system:
(1) The switch gas circuit is shown in Figure 1. When valve 1 and valve 4 are closed and valve 2 is opened, the mechanical vacuum pump III vacuums container I, and the air flows through the pre-vacuum pumping pipeline; when valve 2 is closed, valve 4 When opened, the mechanical pump can vacuum the diffusion pump alone; when valve 1 and valve 4 are opened at the same time, the diffusion pump and the mechanical pump can work at the same time to evacuate the container, and the airflow flows through the diffusion pump. It can be seen that the function of the valve in this operation is to switch the air path and change the route of the air flow.
(2) Control the air flow and adjust the vacuum degree. In Figure 1, the opening angle of the valve cover of valve 1 can be adjusted to adjust the air flow through the pipeline; the valve 2 and valve 4 are closed, and the air release valve 3 can The inlet of the pump III is released into the atmosphere; the vacuum degree in the container can be adjusted through the air release valve 5.
(3) Quantitative inflation is shown in Figure 2. There is a small hole of a certain volume in the plunger of the glass valve. When the small hole is turned to the right and connected to the high-pressure gas cylinder, the small hole can be filled with high-pressure gas; when it turns When the left side is connected to the vacuum container, the high-pressure gas of the volume is put into the container, which plays the role of quantitative inflation.
There are many types of vacuum valves, which are usually classified according to the valve’s function, structure, drive mode, material and use. See Table 1 for their classification.
The model compilation method of vacuum valve is stipulated in the national professional standard, and you can consult the relevant standards.
Classification of vacuum valves
According to the function of the valve: low vacuum valve, high vacuum valve, ultra-high vacuum valve
Plastic type according to structure: flap valve, flap valve, butterfly valve, partition valve, gate valve, needle valve, flapper valve
According to the driving mode: manual valve, electric valve, dual purpose valve with flashlight, solenoid valve, pneumatic valve, hydraulic vacuum valve
According to the material: metal vacuum valve, glass vacuum piston (cork), plastic valve
According to application: stop valve, isolation valve, air release valve, throttle valve, reversing valve, closed feeding valve
According to the channel mode: foot valve, straight-way valve, two-way valve, three-way valve, four-way valve