There are more than enough situations involving water in which the solution seems to be: use a water pump. Most people however, won’t have any experience with water pumps and more likely than not have no idea what a water pump is or what it does. To answer those people’s questions, I’ll answer the question: how does a water pump work?
Water pumps are devices designed to replace a body of water, and many other fluids, using an impeller, pressure and a vacuum. Once you place your water pump in any body of water and turn it on, the pressure surrounding the intake changes, creating a vacuum and sucking in the water around the intake. This water will be guided into the main body of the water pump, where it’ll go into the chamber with the impeller. The impeller is rotating at this point and as such will take the incoming water with itself. The water is then propelled out of water pump’s outlet. This whole cycle continues whilst the water pump is turned on. To keep a water pump working of peak efficiency, it’s important to make sure no air is trapped inside of the water pump, as this will massively decrease the pump’s effectivity. The design I just described is known as a centrifugal water pump. Another type, designed to overcome the centrifugal water pump’s weakness to air is the self-priming water pump.
The self-priming water pump mixes any air in the device with water and pumps this mixture, instead of pumping only pure water. This pump manages to do this, because of a reservoir filled with water inside of the pump. As such, it is important to keep this reservoir filled whilst the pump is working. Finally, there are positive displacement water pumps.
These pumps will displace water with both strokes of the device and as such work onder copious amounts of pressure. To protect the pump itself from this pressure it’s crucial to make sure a relief valve is installed.