The invention of the pump itself was a major breakthrough for mankind. It significantly simplified the supply of drinking water. With growing demands for a stable water supply, largely free from pressure fluctuations, and at exactly the same time increasing demands on the energy efficiency of buildings, pumps are now making their contribution as booster pumps. What their task is, how they function and what pressure switches do along the way is explained briefly and succinctly on this page.
What are booster pumps needed for?
A booster pump increases low water pressure and, with that, improves the flow rate. It provides an extra boost to create the water pressure to the required level. Booster pumps tend to be used in pipelines to increase the pressure and so to go the liquid along to the next pump, and in addition for pumping in residential houses or large commercial buildings. An expansion vessel can extend a pressure booster system. By using this expansion vessel, the water pressure is additionally stabilised and thus improved.
Booster pumps in operation
The figure gives a synopsis of the various measuring points inside a pressure booster system:
1 Input pressure ? Pressure
2a Dry run protection ? Pressure
2b Dry run protection ? Level
3 Output pressure ? Pressure
4 Pump performance ? Differential pressure
So how exactly does a booster pump work?
Booster pumps are selected based on application demands. Instead of selecting one large pump, consider selecting multiple pumps with smaller horsepower. Stupid-simple have an impeller that moves water that comes in through the inlet and exits through the outlet. A motor makes the impellers spin. The pumps differ in how they draw the water in and push it out. Some of them work with a spinning propeller, others use an oscillating diaphragm or other pump principles.
What do mechanical pressure switches in booster pumps do?
The mechanical pressure switches in booster pumps are employed for the direct control/monitoring of safety functions to be able to protect pumps with insufficient input pressure against dry running. An example of this is actually the WIKA PSM-520 pressure switch.
Just how do mechanical pressure switches work?
The pressure element of the switch is really a resilient bellow which works against a spring mechanism with an adjustable pre-load force. On the spring mechanism you will find a contact arm for actuating the change-over switch contact. The switch is actuated when the force generated by the pressure in the pressure element is higher than the set pre-load force.
Note
Further information on the many measurement solutions which we offer you for pumps and systems can be found on the WIKA website. Assuming you have any questions, your contact will gladly help you.
Also read our articles
Mechanical pressure switches: How does one set the switch point?
Mechanical vs. electronic pressure switches: Functionality
Further blogs on mechanical pressure switches