Centrifugal pumps are based on the working principle of transferring energy to a fluid by altering its angular momentum by means of a torque which is transmitted from an evenly rotating impeller to the fluid flowing through it.
A centrifugal pump can be described as driven machinery considering the direction of energy flow, turbomachinery considering the nature of energy conversion, or hydraulic turbomachinery considering the nature of the fluid. Centrifugal pumps are able to continuously pump high flow rates at high and very high pressure. For high flow rates centrifugal pumps are clearly more cost-effective and reliable than positive displacement pumps.
Examples of centrifugal pumps are axial flow pumps, mixed flow pumps, radial flow pumps and side channel pumps. For a summary of the many variations of centrifugal pumps see Type of pump and Pump application.
Centrifugal pumps are characterised by values such as their flow rate, head, suction characteristics, flow velocity, total head, pressure, altitude, power, power input, efficiency, pump efficiency, rotational speed and specific speed.