here is my problem. How do you know how many gpm's you are flowing? your saying 180 gpm but how do you know that? Our gauges all work off of PSI. basically you have to know how many gpm's your nozzle flows at what PSI to even use this equation. I just answered my own question ;)
Fixed gallonage nozzles at a certain nozzle pressure...and on the auto nozzles know your possible flow range so you pump to what your ideal gpm is...say 150gpm or whatever your target is...hit that pdp and you in theory should be flowing the correct gpm at the tip. Also there is a much faster method to pumping called the Wes Trainor Method long time Phoenix hydraulics guru. Hose size x gpm/10-10 Hs=1 for 2.5, 2 for 2" and 3 for 1.75" So 75 psi, 150 gpm nozzle 200' line of 1.75 would be.. HSxGPM÷10-10 3x150= 450...450÷10=45....45-10 =35 So 35psi FL per 100' 35+35+75 noz=145 psi pdp +/- 5psi for any elevation. Makes hoselays really easy to do rapidly.
