Two Different Ways of Moving Fluid

In considering the centrifugal pump vs positive displacement pump, it’s important to look at the basics of mechanics. The centrifugal pump makes use of the rotating impeller which is responsible for imparting energy to the fluid being pumped and moving it out from the discharge end of the pump. On the other hand, the positive displacement pump uses mechanical action to move the fluid out from the chamber.

Flow Rate and Pressure Response

The effect of pressure changes is experienced quite differently by each type of pump. The positive displacement pump has a flow rate that remains constant regardless of pressure variations, thus providing reliable pumping action for accurate dosing purposes. On the contrary, the centrifugal pump works well at a particular pressure level, and the flow rate decreases with deviation from that pressure level.

Handling Viscosity and Sensitive Fluids

Viscosity is another deciding factor. As the viscosity of the fluid increases, the efficiency of the centrifugal pump decreases, but the efficiency of the positive displacement pump increases because thicker liquids will fill up the clearance of the mechanism efficiently. In addition, the positive displacement pump creates less shear on the liquid than the centrifugal pump.

The Right Pump for the Right Job

A centrifugal pump is used to move large amounts of thin liquids such as water under low pressure conditions. The portable nature of the pump makes it suitable for use in small spaces. A positive displacement pump is appropriate for viscous liquid transfer and oil transport among others.

It is important to learn about these pumps in order to determine which one would work best for your needs.
Lakeside Equipment Corporation has decades of experience helping facilities select and implement the right pumping solutions for water and wastewater treatment needs - ensuring reliable performance no matter which pump type fits the job best.