The kind of valve is a safety valve which directly loaded by spring and sealed by rubber, and it adopted to the style of direct-connect style, the strap and the screw air compressor and air-storage vessel.
The safety valve is a kind of balance structure valve accord the balance theory of air pressure and spring. When the adjust outfit of air compressor are good working, the pressure of vessel P less than the set pressure PS(pressure less than power of spring)and the valve core will close. So the pressure of vessel will not leak by safety valve and air compressor will keep good working. When the adjust outfit of air compressor are not working, the pressure of vessel P exceed the set pressure PS(air pressure exceed the power of spring)and the valve core will open, the high pressure air of vessel will be let into the by safety valve in order to avoid destroy the air compressor.

Accord national standard GB12241-2005, GB12242-2005, GB12243-2005