Mechanical diaphragm pumps are established as one of the most popular positive displacement pump types. The pump’s popularity is attributable to its simple design. The diaphragm and the valves are the only parts that come in contact with the fluid, hence servicing is easier compared to other types with complex structure. Furthermore, diaphragm pumps have good self-priming capability, making them suitable for fluid transfer applications where high suction lift is required.
They also provide controllable flow rates, which is the main reason why they are one of the most broadly adopted positive displacement pump types across a broad spectrum of industries. They are especially in demand in sectors that require accurate metering like in chemical manufacturing and processing facilities.
Diaphragm pumps, in general, give good chemical compatibility over centrifugal, piston pumps or lobe pumps.
Reciprocating Diaphragm and Valves
The basic design of a mechanical diaphragm pump is that one side of a chamber is made up of a diaphragm, which is blocked at the inlet and discharge ports via ball valves. The diaphragm is a round disc composed of a flexible material which is pushed forwards and backwards in a chamber via a mechanical shaft. As the diaphragm is pulled inwards on the suction stroke, the volume of the chamber expands and the ball valve at the inlet opens, introducing fluid into the chamber. On the discharge stroke, the ball valve at the discharge port opens as the inlet valve shuts.