[quote name='Ladder 68' post='127682' date='Jul 9 2007, 23:50 ']At that pressure we are flowing approximately 165GPM using an automatic nozzle.[/quote]
I'm not sure what type of nozzle you are using but the automatic nozzle manufacturers (especially TFT) always taught that on 200' of 1 3/4" hose that if you flowed it at 150 psi pump pressure that you would be flowing 150 gpm at the nozzle.
In DC our pump manual states that 100' of 1 1/2 hose has 30 psi friction loss when flowing 125 gpm. I was taught, and many have told me, that that number may be a little low. I was always taught that it was 35 psi (some may differ over whether it's 30, 35, or even 40 as that has sometimes been controversial over what it exactly is). Of course, the quality of the hose you are using will have a big effect on your friction loss.
I'm not sure what type of nozzle you are using but the automatic nozzle manufacturers (especially TFT) always taught that on 200' of 1 3/4" hose that if you flowed it at 150 psi pump pressure that you would be flowing 150 gpm at the nozzle.
In DC our pump manual states that 100' of 1 1/2 hose has 30 psi friction loss when flowing 125 gpm. I was taught, and many have told me, that that number may be a little low. I was always taught that it was 35 psi (some may differ over whether it's 30, 35, or even 40 as that has sometimes been controversial over what it exactly is). Of course, the quality of the hose you are using will have a big effect on your friction loss.