Difference Between Centrifugal Pump And Positive Displacement Pump Pdf

difference between centrifugal pump and positive displacement pump pdf

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There are two main types of pumps available: positive displacement and centrifugal rotodynamic pump. Positive displacement pump: the working principle involves an operation that moves fluid by trapping a fixed volume, usually in a cavity, and then forcing that trapped fluid into the discharge pipe. Centrifugal pump: this involves the transfer of kinetic energy from the motor to the liquid by a spinning impeller.

The Differences Between Centrifugal Pumps Vs. Positive Displacement Pumps

My Enquiry List: 0 items View list. Enquiry List. There are two main families of pumps; positive displacement and centrifugal rotodynamic , both of which have their uses and best areas of application. It is important however to be able to identify when each pump type should be selected, which ultimately comes down to their working principle and the application at hand. Positive displacement pumps are characterised by an operation that moves fluid by trapping a fixed volume, usually in a cavity, and then forces that trapped fluid into the discharge pipe.

Centrifugal and positive displacement pumps are powerful tools that can move fluid through complex industrial and municipal systems. Both centrifugal and positive displacement pumps transfer water from an inlet point to an outlet point at a controlled degree of force and quantity. However, the mechanisms they use are different. Centrifugal , or aerodynamic, pumps have a spinning impeller that draws the fluid into the pump and forces it out of the outlet point at an increased velocity. Each type of pump works best with different types of fluid. Positive displacement pumps can handle highly viscous fluids, and their flow rate can increase as the fluid gets thicker. Also, positive displacement pumps can handle shear sensitive fluids—or fluids that change when force, stress, or pressure is applied—whereas centrifugal pumps cannot; the impellers present a risk to the fluid.

DIFFERENCE BETWEEN A CENTRIFUGAL PUMP AND A POSITIVE DISPLACEMENT PUMP

A positive displacement pump makes a fluid move by trapping a fixed amount and forcing displacing that trapped volume into the discharge pipe. Some positive displacement pumps use an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant through each cycle of operation. Rotodynamic pumps or dynamic pumps are a type of velocity pump in which kinetic energy is added to the fluid by increasing the flow velocity.

JavaScript is disabled for your browser. Some features of this site may not work without it. Author Purcell, John E. Metadata Show full item record. Abstract Positive displacement and centrifugal pumps sometimes seem to inhabit different worlds. Users are generally much more familiar with one type than the other.


The obvious difference between the two is in the way they operate. As displayed above, centrifugal pumps impart velocity to the liquid, resulting in pressure at the outlet. Positive displacement pumps capture confined amounts of liquid and transfers it from the suction to the discharge port.


Positive Displacement vs Centrifugal Pumps

The dividing line in the world of pumps falls between those that push and those that throw, or more specifically, positive displacement and dynamic displacement. Positive-displacement machines use some form of variable-volume cavity to draw fluid in and push fluid out. Machines come in many rotary and reciprocating styles. Dynamic-displacement machines rely on motion imparted to the fluid by way of a rotating element, called an impeller, to increase the velocity of the fluid and so its pressure. The selection of one pump type over another is determined by many factors such as flow rates and pressures required, fluid viscosities, etc.

Often times it is hard to determine when to use a centrifugal pump or a positive displacement pump. Each has its own unique properties with respect to flow rate, pressure, viscosity, and efficiency. What is the difference between a positive displacement pump vs a centrifugal pump? Centrifugal pumps produce flow by creating pressure.

Centrifugal Pumps vs. Positive Displacement Pumps

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