I'd second running your own tests and developing your own cards. We've found that different hose and discharges have a significant difference in FL. We use the C Formulas as a baseline, but nothing beats a calibrated flow meter and pitot gauge to determine actual friction loss and preset gauges.
Bob, did you guys test your hose and pumps to validate your numbers? In particular the 1.75" FL you show as 20 psi by formula would be accurate at less than 125 gpm and the 3" FL at 5 psi is theoretically/mathematically correct for under 335 gpm both far less GPM than normally flowed through the respective hoses. Again, these number could very well be true given newer hose tends to be "oversize" in dia. and liners tend to create much less drag than older types. We've found a huge difference in our three types of 1.75" hose all between 35-72 psi FL @ 185 gpm per 100 ft.Hi Colin,
We developed a simple "rule of thumb" friction loss for our engineers. 1-1/2 hose is 30 psi per 100 1-3/4 hose is 20 psi per 100
2-1/2 hose is 10 psi per 100
3 hose is 5 psi per 100
All you have to add is your nozzle pressure and lenght of line and you are all set!
We use 50 psi nozzles for our 1-3/4. we carry 200 ft with nozzle, FL=40+ Np 50 = 90/100 Pump discharge pressure.
Some engineers have marked the gauges for normal pump ops, knowing if at the add a line they know how much to adjust the pump throttle.
Come visit me a "Let's Talk Pumps", FDIC, Thursday 1030-1215, Room 206-207
Hope this helps,
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