Operating point of Pump

 Best Efficiency Point (BEP):

The Best Efficiency Point (BEP) is the point of highest efficiency of the pump. It is not possible to completely convert kinetic energy to pressure energy. Some of the energy is always lost.

The operating point will always be where the system curve and Head flow curve intersect. Operating the pump beyond the BEP not only decreases its efficiency but also subjects it to mechanical and hydraulic problems. For centrifugal pump, an increasing system resistance will reduce the flow of pump.

Therefore, the pump is recommended to operate in a range of ±15% around the BEP. The pump should never be operated at a flow rate lower than 60% of the Best Efficiency Point. If we operate pump beyond BEP range, then excessive vibrations that can destroy its bearings. If we operate pump at a flow rate higher than 120% of the Best Efficiency Point, then cavitation will create inside the pump and that destroys its impeller.