A pump is a device for lifting, transferring, or moving fluids by suction or pressure from one position to another.
The centrifugal pump is a type of pump that uses the kinetic energy of a rotating impeller to impart motion to the fluid The rotating impeller accelerates the fluid through its vanes and into the pump casing where the kinetic energy
of the moving fluid is converted to potential energy at higher pressure. As the fluid leaves the impeller through the pump discharge, more fluid is drawn into the pump inlet where the pressure is lowest. This fluid passes through the impeller as still more fluid enters the impeller.
There are three classifications of centrifugal pumps: radial flow, mixed flow and axial flow based on the direction the fluid enters the inlet (eye) of the impeller, see figure 1.2. Radial and mixed flow pumps are either single or double suction designs.