Centrifugal Pump Specifications

• A centrifugal pump is a basic pump that is used to move liquid from one place to another. It is excellent for high-volume situations, but it is not particularly efficient. This means that water pumping forward always has some water flowing backward at the same time, thus detracting from the total output.

Impeller

• The impeller is the key part of a centrifugal pump. It is the moving part, attached to vanes that resemble a fan. As they spin, they create a flow by changing the liquid's pressure; as the liquid on the outside edges of the impeller becomes more pressurized through its higher energy, the liquid in the center becomes less pressurized.

  The faster the impeller spins, the higher its capacity for pressure and volume. This is because a faster-moving impeller will create higher pressure on the outside edges of the vanes, thus increasing the throughput of the pump.

Vanes

• The vanes are symbiotic with the impeller. Without the vanes, the impeller is just a spinning piece of metal; without the impeller, the vanes are just bulky pieces of metal that cannot accomplish anything due to lack of movement.

  The key point about the vanes is that they move the liquid. The larger they are, the more powerful they are, and the more liquid they can push through.

Suction Eye

• The suction eye is the point at the center of the impeller. It is where the water enters the centrifugal pump. It is created by the fact that pressure is high on the outside edges of the centrifuge and low in the middle; as liquid sloughs off the discharge valve on the side, the suction eye takes more liquid in to compensate for it. However, the pressure is always balanced--the suction eye pressure is always higher than the pressure in the discharge valve, otherwise the pump would not be effective.