Products >> Centrifugal Pumps/Displacement Pumps, Vacuum Pump, Diaphragm pump, Submersible Pumps

Diaphragm pumps use a positive displacement design rather than centrifugal force to move water through the casing. This means that the pump will deliver a specific amount of flow per stroke, revolution or cycle.

Engine powered versions are the most common and typically use the drive shaft to turn an offset connecting rod that is coupled to a flexible diaphragm. The connecting rod alternatively raises (expands) and lowers (contracts) the diaphragm at a RPM rate.

A vacuum is created inside the pump casing each time the diaphragm is raised. This opens the inlet valve and seals the discharge valve allowing a liquid and air to enter the pump. When the diaphragm is lowered the resulting pressure seals the inlet and opens the outlet valve purging the pump housing of water and air. Unlike centrifugal designs the water inside the casing is positively displaced and no recirculation occurs.

Types of diaphragm pumps

Diaphragm pumps are subcategorized into three types. The first type is one that is sealed on both sides with pumped fluid on one end and air or hydraulic fluid on the other. This type of diaphragm is flexible enough to cause increase or decrease in the pump volume chamber. With the help of non-return check valves, the reversed flow of fluid is prevented.

A second type of diaphragm pump is one that works with the help of volumetric positive displacement. In this type, electromechanical measures make the pump work instead of employing air or oil in the process. The mechanical action makes the pump more flexible as the other side of the diaphragm pump is open.

The third type of diaphragm pump is one that has unsealed diaphragms. Either one or more of these diaphragms work even without using any seal. Fluid is pumped on both sides while the diaphragm is flexed. The flexibility causes the volume of production to change.