Constuction: It consist of a diaphragm, displacement chamber, two valves, and a driving mechanism. The diaphragm is made of a flexible material compatible with the pumped media. It is sealed in place between the side of the displacement chamber and an attached flange. The chamber's volume is slightly greater than what the diaphragm can displace. The valves are typically spring-loaded ball valves or flapper valves made of the same material as the diaphragm, and they function to admit the fluid in and out of the chamber. The driving mechanism is what flexes the diaphragm - in the diagram below, the drive mechanism is a spring activated by a solenoid. Working: Diaphragm pumps are positive displacement pumps, meaning they use contracting and expanding cavities to move fluids. Diaphragm pumps work by flexing the diaphragm out of the displacement chamber. When the diaphragm moves out, the volume of the pump chamber increases and causes the pressure within the chamber to decrease and draw in fluid. The inward stroke has the opposite effect, decreasing the volume and increasing the pressure of the chamber to move out fluid. This operation is very similar to the draw in, push out, concept of human breathing.
