Product Features: 1. Suitable for industrial frequency oil injection screw air compressors. 2. It is a normally open intake valve, with control pressure signal input, and the intake valve is closed. 3. Special structural design, without the problem of large start-up load of normal normally open intake valves. 4. The intake valves of the whole series have a check function, and will not inject fuel under emergency shutdown conditions. 5. The intake valve has the function of unloading and replenishing air, which can effectively eliminate the cavitation noise generated by the main engine. 6. The intake valve integrates a discharge valve, an air supply valve, a solenoid valve, and a proportional valve, which is convenient and fast to install.