The invention of the pump itself was a significant breakthrough for mankind. Deadline simplified the supply of normal water. With growing demands for a well balanced water supply, largely clear of 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 this article.
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 desired level. Booster pumps are often 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 likewise stabilised and therefore improved.
Booster pumps functioning
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. 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. Some of them use 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 used for the direct control/monitoring of safety functions so that you can protect pumps with insufficient input pressure against dry running. An example of this can be the WIKA PSM-520 pressure switch.
How do mechanical pressure switches work?
The pressure component 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 when the force generated by the pressure in the pressure element is greater than the set pre-load force.
Note
Further information on the many 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: How does one set the switch point?
Mechanical vs. electronic pressure switches: Functionality
Further blog posts on mechanical pressure switches