Air Operated Plunger Pumps
... utilize a piston within the cylinder to create an alternating increase and decrease in flow between the suction side and discharge side. As the piston move backward (up), the available volume in the intake portion of the cylinder increases. A one-way suction valve opens to allow fluid to enter. Air Operated Plunger Pumps are built with a unique hollow piston and internal check valve. On the forward stroke (down), the fluid is compressed and flows through the piston into the discharge side of the cylinder, trapped from returning by the check valve. On the next backward (up) stroke, the fluid is forced out through the discharge tee.