Pump never sucks, it always create partial vacuum by Centrifugal or Regenerative working principle. The Earth's atmospheric pressure pushes fluid into suction pipe of pump once partial vacuum created by Pump, then the fluid is gets pressurised due to design and construction of the pump. This makes the fluids to transfer from one point to another with adequate pressure.
Right pump for a right application will make 50% success of any pumps. Few mandatory parameters are need to understand and considered before selection of pumps. The input of electric water pumps are power supply and the output of pumps are water discharge and pressure head.
Flow Rate or Discharge (Q): The volume of water to be delivered or transferred is known as Flow rate or discharge of a Pump. It is measured in unit of liters per hour, liters per second, liters per minute, cubic meter per hour or gallons per minutes.
Head (H): The pressure build by a pump to lift and deliver a certain volume of water against a vertical distance is called as Head of a pump. Usually measured in meter or feet.
Power (P): The input power supplied to a driver of a pumps to create torque and drive, in our case prime mover an AC electric motor. The power supplied are measured in kilowatt or horsepower.
Efficiency (η): Efficiency of a Pump is defined as the ratio between water horsepower output from the pump to the shaft horsepower input for the pump.