Comparison Between Centrifugal Pump and Positive Displacement Pump
Centrifugal pump is one of the commonly used pumps among pumps used for various applications. However, centrifugal pump may not be right one for sanitary processes.
For the sanitary process all components like Sanitary Pumps and flow pumps that you may choose should be chosen with careful consideration.
Often, we need to decide between centrifugal and positive displacement pumps which are few very commonly used pumps in this industry. Let us therefore make a comparative study about both these two types of pumps.
What is their difference?
- The positive displacement pumps generally provide a continuous flow irrespective of pressure, whereas centrifugal pump pressure will depend on their changing flow. This may have little impact on the speed of the sanitary processes.
- Also, the effect of viscosity for each type of pump will be based on capability of the pump. Centrifugal pump may lose flow as the viscosity increases hence it will suit more for transferring applications of liquids with low viscosity.
PD pump flow will increase with liquids of higher viscosity. For positive displacement pumps, it will offer higher efficiency rate which is not found in centrifugal pumps.
- Normally PD pumps can produce more pressure as compared to centrifugal pumps, and also, they operate at much lower speed too. Therefore, PD seals also last longer than the seals of centrifugal pump.
- In very high flow conditions, centrifugal pumps will perform better. Whereas for applications where high pressure or low flow rate is needed positive displacement pumps will be preferred.
Things to check while choosing any pump component of sanitary process
Before choosing the best pump in order to carry out your process you need to consider the following few characteristics:
- Desired flow rate
- Total head or its pressure capability
- Suction lift
- Fluid characteristics
Positive displacement pumps may be preferred for following conditions:
- For thick and viscous liquid displacement
- In dry condition or even if liquid is not present this type of pump will be suitable.
- You can easily control the rate of flow to match with other pump components
- More suitable for suspended solid items.
Centrifugal pumps may be preferred for following conditions:
- More suitable for thin oil, water or any other similar liquids which are to be displaced in high volumes.
- Not suitable in without liquid condition.
- Suitable for high volume liquid displacement.
- More suitable for sensitive fluids.