Working principle of intake valve:1. The air intake control valve is mainly composed of valve body, valve, piston, cylinder, spring, sealing ring, etc., has control block control solenoid valve installed on the side of the valve to integrate the functions of on / off adjustment load reduction, mute, pressure reduction close exhaust. 2. When reducing the load, a small part of the gas is released through the small hole on the valve to balance the intake volume of the small hole on the intake control valve, so as to maintain the pressure in the separation tank at 0.2-0.3mpa for normal air compressor oil circulation. 3. The opening closing action of the air inlet control valve is automatically controlled by the pressure sensor solenoid valve of the regulating system ZD. It is very important for the reliability of screw machine whether the opening closing action of intake control valve is flexible. The intake valve is the breathing port of the air compressor.After the ordinary air enters the intake valve reaches the compressor head, it is compressed to produce compressed gas. It can control the loading unloading of air compressor as well as the size flow of air pressure. It is the main component of the air compressor (intake control system). The intake valve has two functions: 1. Control the opening closing of the intake channel. 2. Control air intake.