View Full Version : Pressure Sprayers

Randy Meijer
07-03-2005, 10:26 PM
I know what they are and what they do; but would like to know "HOW" they work. Specifically, what kind of pump do they use to increase the "house" pressure to the thousand + pounds at the nozzle. Any information would be appreciated. Thanks!!

Ken Garlock
07-04-2005, 11:07 AM
Randy, the ones I know about are powered by a 3 to 5 hp gas engine that runs the equivalent of a hydraulic pump not unlike you see on a farm tractor. You can get a good feel for the pumps at Northern Tool (http://www.northerntool.com/webapp/wcs/stores/servlet/CatDsp?storeId=6970&N=32) :)

Norman Hitt
07-04-2005, 4:27 PM
Randy, maybe the easiest to explain their "workings" is that they do basically the same thing as an air compressor. They take in low pressure-high volume water and run it into a "Triplex" (3 piston) or larger, (more pistons) pump which is capable of high pressures since they are a "positive displacement" type pump and then on out through the hose and spray nozzle. The small orfice in the spray nozzle is what keeps the pressure high. As the size of the spray tip orfice, (hole diameter), is increased, the pressure would decrease on a sliding scale to some fixed minimum pressure boost, depending on the individual pump and it's outlet size and number of pump stages, (pistons). If I remember correctly, the outlet of the first piston feeds to the inlet of the second piston, and it's outlet feeds to the inlet of the third piston, etc. This is what allows them to get such high boost pressures with such a small unit.

Hope this makes sense