These pumps operate by developing a high liquid velocity and converting the velocity to pressure in a diffusing flow passage. Dynamic pumps usually have lower efficiencies than positive displacement pumps, but also have lower maintenance requirements.
Dynamic pumps are also able to operate at fairly high speeds and high fluid flow rates.
A centrifugal pump consists of an impeller and an intake at its center. These are arranged so that when the impeller rotates, liquid is discharged by centrifugal force into a casing surounding the impeller. The casing is there in order to gradually decrease the velocity of the fluid which leaves the impeller at a high velocity. This velocity is converted to pressure which is needed to discharge the fluid. Some of the advantages of cenrtifugal pumps are, smooth flow through the pump and uniform pressure in the discharge pipe, low cost, and an operating speed that allows for direct connection to steam turbines and electric motors.