1)Start: 

The motor starts, the host revolves and the air come through the intake valve. The compressed oil gas enters the oil-air tank and the system pressure rises gradually.

2)Disassembly:

When the pressure rises to the upper limit of differential pressure switch,

the differential pressure switch sends an electrical signal to three-way  electromagnetic valve. The electromagnetic valve stops providing the air to the cylinder and control the cylinder away from the pressure. The butterfly valve shuts and make the hole inlet. At that time the check valve can timely and quickly shut closely and meanwhile open the discharge valve to release the pressure to the basic oil pressure. Then the air compressor works in the state of the unloading.  

3)Stopping:

The stopping signal is from empty too long or that the system pressure is in the upper limit of the pressure. The motor and the host stops and no longer inlet. The inner check valve shuts quickly and make sure there is no spitting oil. Then the discharge valve continue to empty until the pressure is up to the external atmospheric pressure.