Positive displacement pumps and centrifugal pumps are the two most common types of pumps available for commercial applications. Positive displacement pumps in GA are able to sustain a relatively constant fluid flow rate, at a given speed, regardless of the discharge pressure. This fundamental feature sets them apart from centrifugal pumps, which are also referred to as negative displacement pumps.
Positive displacement pumps move fluids by pulling them into an expanding space. This cavity then reduces to discharge the same fluids. These pumps typically come in three types – rotary, reciprocating, and linear.
This classification is based on the device the pump relies on to transfer the liquid. The first type utilizes rotating instruments such as gears and screws to complete the task. The second type achieves positive displacement by utilizing piston or plunger machines; a hand pump is a good example of this. The last type depends on ropes and chains.
Here are a few important things you should know before you purchase your next positive displacement pumps in GA.
1. Positive displacement pumps can be used when a constant flow rate is mandatory.
2. These pumps should never be operated with a closed valve because unlike centrifugal pumps, they don’t have shutoff heads and will continue to pump. This can cause a discharge line to leak or even burst.
3. An internal or external safety controller should be installed on the discharge end when using these pumps to prevent damage.
4. Positive displacement pumps in GA are best suitable for applications that require only moderate flow and pressure rates.
5. The rotary type of positive displacement pumps are very efficient but they are not suitable for high flow rate uses. The revolutions per minute can be elevated to increase the flow rate, but this will eventually wear down the rotary mechanism, while increasing the clearance between the rotor and the side walls and decreasing efficiency.
6. Like centrifugal pumps, positive displacement pumps in GA are not self- priming.
7. Unlike most centrifugal pumps, positive displacement pumps can remove trapped air in the system on their own.
8. However, these pumps can only function when the pressure at the inflow end delivers the least pressure required by a unit. This is also essential to getting rid of any trapped air.
9. These pumps are best suited to handle high-viscosity fluids.
10. Positive displacement pumps in GA are reliable machines that are available in a wide variety of configurations, making them the preferred type of pumps to handle a broad range of fluids.
For more detailed information regarding positive displacement pumps in GA and to get professional advice on choosing the right type to suit your needs, please call our office today to speak with one of our experts. Keep in mind that we specialize in a variety of advisory and installation services, all designed to help you get the most out of your liquid handling equipment.