Centrifugal Pumps

What is a centrifugal pump?

The most common type of pump with dozen of different configurations available including: fire pumps, end suction pumps, chopper pumps, grinder pumps, magnetic drive pumps and many more.

Centrifugal pumps use one or more impellers which attach to and rotate with the shaft, providing the energy that moves liquid through the pump and pressurizes the liquid to move it through the piping system. They are usually quick to install, require less maintenance than other alternatives, and are generally easy to repair.

They are usually the best choice for lower viscosity (thin) liquids and high flow rates. They pumps are also used in many residential, commercial, industrial, and municipal applications. Multi-stage centrifugal pumps have more than one impeller, and are used for applications that require higher pressure or head.

Centrifugal pumps generally work within the following ranges:

• Flow rate ranges between 5 and 200,000 gpm
• Total head (pressure) ranges between 10 and 7,500 ft
• Horsepower ranges between 0.125 and 5,000 hp

There are a wide variety of materials of construction, ranging from various plastics and cast iron or stamped stainless steel for lighter duties - to bronzes, stainless steels, exotic alloys, and specialty plastics for more corrosive, abrasive, hygienic, or other difficult applications.

Piping connections on centrifugal pumps are available with standard pipe threads on smaller sizes, and flanges on larger sizes. Specialty connections are available from some pump manufacturers for particular applications. The normal drivers supplied are A.C. induction motors, but some manufacturers offer pumps with D.C. drives or adaptable to other power transmission devices such as engines and gear boxes.

How do they work?

A centrifugal pump works by:

1. First the pump directs the liquid in the system into the suction port of the pump and from there into the inlet of the impeller.
2. The rotating impeller moves the liquid along the spinning vanes, which increases the velocity energy of the liquid.
3. The liquid then leaves the impeller vanes and then moves into the pump volute or diffuser casing, where the high velocity of the fluid is converted into high pressure through a diffusion process.
4. The fluid is then guided into the discharge port of the pump and from there out into the system, or on to the next stage in the case of a multi-stage pump.