The flexible impeller pump is a rotating pump. It is capable of sucking the liquid itself into the pump, but the pump has to be filled with liquid. If the pump is running dry, the life time of the pump will be greatly reduced.
The flexible impeller pump consists of a rotor with flexible vanes attached to it. The pumphouse is smaller in a specific part between the outlet and inlet of the pumphouse. When the rotor rotates, the vanes rotate with it. When the vanes reach the smaller part the vanes are pushed down, making the space between two vanes smaller, pushing the liquid into the outlet. When the vanes exit the smaller part of the pumphouse, they regain their normal form, creating an increase in volume between two vanes. The liquid from the inlet then flows into the empty space.
The flexible impeller pump is suitable to pump clean, troubled and highly viscous liquids. The pump can rotate in both directions, changing the inlet to the outlet and vice versa. Because of it's simple construction, the pump is easily cleaned.

(1) While the rotor rotates, the vanes of the pump regain it's form creating an increase in volume between the two vanes. The increase in space between two vanes will suck the liquid into the pump.

(2) When the liquid has filled the empty space, it is trapped between the two vanes and the pumphouse. The rotor rotates, transporting the liquid to the outletside.

(3) When the liquid reaches the outlet side, the vanes are pushed down because of the smaller pumphousing, and the space between two vanes decreases. Because the decrease in volume between two vanes, the liquid inside is pushed out, to the outlet.

(1)	(2)	(3)