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An insight into the working of Grundfos pressure booster pumps

Grundfos mq3-45 pumps are the most common of all the well pumps used now-a-days. They are very powerful, reliable and efficient. These Grundfos booster pumps work well by suction. The suction is formed by producing a vacuity. The electric motor forces the impeller to carry water through a jet. The velocity of the water is increased in this way and it creates the suction when water exits the jet. There is a venture tube behind the jet which increases in diameter when water flows through it.

Pressure boost pump system

The wells can be shallow or deep. Therefore, the Grundfos mq3-45 pumps work differently in both the cases. In the shallow wells, one can use only a single drop setup of the pump. In this set up, there is a single pipe that goes through the well and carries the water up to the pump. While in the deep wells, the jet and the impeller are separately placed. One pipe is used to supply water to the jet while another pipe carries the water up to the well. This setup of two pipes is known as double drop setup.

Priming and storage in Grundfos mq3-35 pumps

The booster pumps must be primed, which means that pump should contain some amount of water all the time. The pump shifts the water to a storage tank. This tank contains an air bladder which creates pressure when filled up with water. The pressure should be between 40-60 pounds per square inch, i.e. PSI. The bladder upholds the pressure. When this pressure drops by a specified amount, it activates the jet pump.


Grundfos mq3-35 pumps of different capacities are available in the markets. Usually they are differentiated from each other according to pressure or Gallons per Minute. It is necessary that one purchases the pump that is compatible with the well for the best results.