Understanding The Working Formula Of Positive Displacement Pumps
To properly understand the working formula of positive displacement pumps, you need to differentiate the same from centrifugal pumps, especially the way in which each operates.
The working procedure
Positive displacement pumps have a series of working cycles. Each cycle pushes a certain volume of fluid and moves it mechanically through the system. The back pressure of the pump is dependent on the type of pump and the liquid being handled. The maximum pressure developed in the pump is limited by the mechanical strength, system and the driving capacity. However, the effect of this pressure can be controlled by simply attaching a pressure relief or safety valve.
The major advantage of the positive displacement pump is its ability to deliver consistent capacity of fluid. This is because, the outlet is solely dependent on the basic design of the pump and the speed it develops. This means that somehow if the liquid does not move through the system at the required flow rate, it can always be rectified with the help of force development and the safety release valve.
Understanding the centrifugal pumps
Centrifugal pumps may be the best choice in household applications. But things may change when it comes to industrial requirement. The above mentioned advantages are not achievable from a centrifugal pump. If a fluid is filled with rock and stones, pumping it through the centrifugal can damage the blades that are responsible to create extreme force. The design of a centrifugal can only react to the pressure demand of the system, and if the back pressure on the pump changes so will the capacity of the pump.
The advantages of PDPs
Positive displacement pumps are suitable for handling highly viscous liquids. As they are self-priming, they have the ability to handle liquids with a certain volume of entrained air. One such example is the piston pump. It is the oldest and best known in the category of positive displacement pump. It has a piston or plunger that forces liquid from the inlet to the outlet of the pump. When the piston moves upwards, it reduces the pressure in the pump body, causing the pressure in the suction line to open the suction valve and permit the liquid to flow into the pump.
Understanding the working procedure of PDP is crucial as it lets you to determine the actual model of a pump best suited for your requirement.
To know more about positive displacement pumps, stay tuned to our blog space.