Diaphragm pumps are for applications in all cases where the capacity to transfer thick liquids, containing abrasives or solid bodies in suspension, is required, and a high flow rate where the discharge head is not high.
The diaphragm pump is a 'positive displacement' pump which means for every pulse, the same amount of fluid, air, or mix of both is pumped.
When the diaphragm is drawn up, this discharge valve is sucked closed, and at the same time the suction flap valve opens to let the liquid into the pump chamber.
The diaphragm then begins to come down, forcing the suction flap valve closed so the liquid has to exit on the discharge side of the pump.
Because of the action of the pump and the simple design, these pumps can handle and pass large solids without damage. They can also run dry 24/7 with no damage.