The invention of the pump itself was a major breakthrough for mankind. It significantly simplified the way to obtain drinking water. With growing demands for a stable water supply, largely free from pressure fluctuations, and at the same time increasing demands on the power efficiency of buildings, pumps are actually making their contribution as booster pumps. What their task is, how they function and what pressure switches do in the process is explained briefly and succinctly in the following paragraphs.
What exactly are booster pumps necessary 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 desired level. Booster pumps tend to be used in pipelines to increase the pressure therefore to move 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 therefore improved.
Booster pumps in operation
The figure gives an overview of the different 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
How 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. Booster pumps 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. Many 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 as a way to protect pumps with insufficient input pressure against dry running. Strange of this is actually the WIKA PSM-520 pressure switch.
How do mechanical pressure switches work?
The pressure part of the switch is really a resilient bellow which works against a spring mechanism with an adjustable pre-load force. On the spring mechanism there is a contact arm for actuating the change-over switch contact. The switch is actuated as soon as the force generated by the pressure in the pressure element is higher than the set pre-load force.
Note
Further information on the various measurement solutions which you can expect you for pumps and systems can be found on the WIKA website. Should you have any questions, your contact will gladly help you.
Also read our articles
Mechanical pressure switches: So how exactly does one set the switch point?
Mechanical vs. electronic pressure switches: Functionality
Further blog posts on mechanical pressure switches