Centrifugal pumps

Frequently Asked Questions About Centrifugal Pumps

What is a centrifugal pump?

A centrifugal pump is a type of water pump used to transport fluids by converting rotational kinetic energy into hydrodynamic energy. The pump features a rotating peripheral impeller that generates suction at the pump inlet, drawing the liquid inside. It then uses centrifugal force to propel the liquid outward through the discharge outlet. Centrifugal pumps are commonly used in industrial, agricultural, and commercial applications to pump water, chemicals, and other liquids. They have a simple design, are easy to operate, and accommodate a wide range of flow rates and pressures.

What applications are Elpumps centrifugal pumps suitable for?

Elpumps centrifugal pumps are designed for small-scale residential or commercial use. Centrifugal pumps are used, for example, to supply clean water, boost water pressure, drain basements, cellars, and pools, irrigate small gardens and lawns, and pump water from wells, boreholes, or rainwater collection systems. They are also suitable for pumping non-corrosive, non-flammable liquids such as oil, as the bronze impeller ensures spark-free operation.

Which is better: a centrifugal pump or a jet pump?

It depends on your needs. In general, centrifugal pumps are more efficient than jet pumps when it comes to moving liquids to greater heights and achieving higher flow rates, which is crucial in commercial or industrial settings. Jet pumps, on the other hand, are often more efficient for shorter distances and lower flow requirements, which is typical in domestic applications such as supplying water to a home or garden.

Another major advantage of jet pumps over centrifugal pumps is their resistance to air accumulation in the pump housing. Jet pumps can easily expel small amounts of air and continue operating without interruption. Centrifugal pumps, however, cannot do this—if even a small amount of air is trapped in the housing, the pump immediately stops pumping and must be re-primed. Therefore, a third advantage of jet pumps is that they are self-priming, whereas centrifugal pumps are not.

In summary, if you need a pump for a specific task in a domestic or small commercial setting—such as pumping oil or other liquids—a centrifugal pump will perform reliably. But for general tasks like garden irrigation, a jet pump (or garden pump) is a better choice.

Do Elpumps centrifugal pumps switch on and off automatically based on water usage?

No, Elpumps centrifugal pumps are not equipped with a pressure switch or flow sensor, meaning they do not automatically turn on or off when you open or close a tap or garden hose. This pump type operates when plugged in and stops when unplugged.

Do these types of centrifugal pumps have dry-run protection?

No. The pump cannot detect whether there is water in the pump chamber, so manual monitoring is necessary if there’s a risk of the water source running dry—such as when pumping from barrels or water tanks. Running the pump dry can burn out the motor, which is considered user error and is not covered by the warranty.

How does a centrifugal pump work, and what is its working principle?

A centrifugal pump is designed to move liquids using centrifugal force. The pump casing houses a rotating impeller driven by a motor. As the impeller spins, it creates rotational energy that pushes the surrounding fluid outward, generating a low-pressure area at the center. This low pressure draws fluid in through the suction port and expels it through the discharge outlet.

Where are the suction and discharge ports located?

The suction port is located at the front of the pump, where the suction hose should be connected. The discharge port is the opening at the top of the pump, where the discharge hose or pipe should be connected.

Do I need a foot valve or a non-return valve? Where should it be installed?

Because centrifugal pumps are highly sensitive to air entering the pump housing, it is strongly recommended to use a non-return valve somewhere on the suction side or a foot valve at the end of the suction hose submerged in water.

Why can a centrifugal pump only operate when it is primed?

A centrifugal pump requires water inside its housing to function. If air is present in the pump casing, the pump cannot draw water and therefore cannot operate. The pump must be primed to remove the air, create a vacuum, and allow water to be drawn in.

How do you prime a centrifugal pump?

To prime a centrifugal pump, remove the priming screw and completely fill the pump housing with water. Then, re-tighten the priming screw.

What should I do if the centrifugal pump won’t prime?

If the pump won’t prime, several factors may be responsible—such as air trapped in the housing, a blocked suction pipe, or a defective seal. First, check whether the pump is properly primed and that all connections are tight. If the issue continues, consult a professional.

Are the Elpumps centrifugal pump models suitable for both domestic applications and industrial applications?

Elpumps centrifugal pumps are designed to be used in domestic applications and light commercial use, such as garden irrigation or water transfer. They are not designed for heavy industrial applications.