difference between centrifugal pump and self priming pump

As the name suggests, centrifugal pumps move the water by means of centrifugal force. The liquid enters the pump through its suction inlet and is made to “centrifuge” by one or two impellers and then driven towards the pump discharge.

In this case, the priming is done manually and you have to make sure the pump primes each time it is put into operation, so the intake pipe must always be full of liquid.

They are versatile and efficient, making them ideal for use in various fields, such as the chemical and petrochemical industry, the pharmaceuticals sector, or for water processing and purification.

As far as their practical application is concerned, classic centrifugal pumps can be used in two ways:

under head, placed at a lower level than the liquid;
over head, placed at a higher level than the suction liquid.
In the former case, the force of gravity alone drives the liquid into the pump; in the latter, the liquid has to be pushed “up the pipe”, or you have to make sure the liquid never drains out of it. A foot valve combined with a tank ready to fill the pipe can be enough to guarantee priming, but the pump may not be able to prime if the valve fails or if the suction liquid contains solid particles capable of blocking it or keeping it open.

This is where a self-priming pump comes into play.Self-priming pumps are able to prime on their own, without the need for any manual procedure. There are several types of self-priming pumps. The most common types are those with a check valve built into the pump body, like the Robusta line.

To ensure self-priming, you have to fill up the body of the pump with water or a liquid that is compatible with the liquid for pumping. The impeller creates internal turbulence capable of removing the air from inside the intake pipe, producing a depression, and then subsequently expelling it through the delivery pipe. The water now rises up through the intake pipe until it fills completely, without the need for a foot valve.

As a result, the pump starts running.

Post time: Jan-05-2024