Williams LD Series Pneumatic Plunger Pumps
The pneumatic diaphragm metering pump consists of a liquid chamber and an air chamber, separated by a diaphragm. In the liquid chamber, the suction (inlet) and discharge (outlet) ports have check valves that control the direction of the fluid flow. A pipe nipple connects the controller to the pump air chamber. In the air chamber, the air/gas power supply from the controller enters and exhausts through the pipe nipple connector. When the controller exhausts the air/gas supply, the liquid suction pressure and the return spring force the diaphragm backwards. The diaphragm stops when the end of the diaphragm stem, which is attached to the air chamber side of the diaphragm, collides with the end of the stroke adjuster.