Single stage centrifugal pumps are the most common pump for fluid transfer in high flow rate, low pressure installations. Centrifugal water pumps are common single stage pumps, however due to the wide range of materials available centrifugal pumps can also be used for other low viscosity fluids such as fuel, oils and petrochemicals. Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuse or volute chamber (casing), from where it exits.