The Way It Works:
During the down stroke of the piston, air is forced into the cylinder by atmospheric pressure through an inlet filter and an intake valve located in the head of the compressor. When the piston reaches the bottom of the stroke, the intake valve closes; the air is now trapped in the cylinder. During the upstroke of the piston, the air is compressed in the cylinder, the discharge valve opens and the compressed air is delivered into the air receiver tank. The total compression, from atmospheric to the final discharge pressure, is accomplished in one stroke of the piston.