Booster pumps are secondary pumps used to increase the pressure of the liquid from the main pipeline. This means that they do not function alone but act as a piece of supporting equipment with the sole purpose of increasing the pressure or head that the main duty pump or gravity tank cannot achieve. They are under the centrifugal pump classification that uses one or more impellers to boost the water pressure.
Pressure boosters are typically used in systems that need to service skyrise buildings with an extremely high head requirement. Also, booster pumps are often paired with a vertical turbine or vertical submersible pumps to further boost the head of irrigation or drinking water pumped from wells. Finally, they are used in many process applications, where the pressure required is more than what the main pump can deliver, or in processes where a second pump is needed to ensure that the main pump does not cavitate.
Technically, since pressure booster pumps fall under the centrifugal pump group, they operate by using centrifugal force to speed up the fluid that goes inside the pump through the impeller eye. The fluid then gains kinetic energy as its velocity is increased and is forced to the end of the impeller vanes. Most of this energy is then converted to pressure energy as the water falls to the volute and pushed out to the discharge. But as we mentioned earlier, most pressure boosters are multistage, making sure that the fluid gets the right pressure needed to reach its final destination.
Pressure boosters can be installed before the main pump or after the main pump or at the pipeline before the set destination. Ultimately, they should be connected with a primary pump since they cannot move water all by themselves.