I agree that good hoseline pressure goes back to training, training and more training! I am starting my 39th year in the fire service and I see alot of pump operators today as handle pullers and throttle turners. As long as water is coming out the end of the nozzle everything is OK. Many operators have no concept of friction loss and nozzle pressures. Why? Most firefighters of today have been using "automatic" nozzles and every time you increase the pressure you increase the gallons flowing, maybe.
We did a 9 month study using flow meters and in-line gauges and found that 82% of our automaic nozzles were defective. We had a target flow of 150 gpm. We found that our "automatics" were flowing anywhere from 38 gallons to 148 gallons and the streams looked the same. All the pump operators knew was we pumped at 120 psi regardless.
We found another problem with our light weight hose. The thermo-plastic lining seperated from some of the sections restricting or clogging the line. We now purchase rubber-lined hose for everything. We looked at various nozzles manufactures and chose the Elkhart 4000-14. It has a fog nozzle (150 gpm@ 50 psi) tip screwed onto a 15/16th built-in smoothbore.Our pdp is 90 psi for both attack lines. (FL= 20 per 100 (40psi total) + 50 psi nozzle pressure = 90 Pump discharge pressure)
The next problem found was that our crosslays were 200 feet. Some of our structures are less that 20 feet from the street. We added a wye to the lower 2-1/2 discharge on both sides. Now we pull off the crosslay the amount of hose needed, break it, and connect to the wye set. Some cases we used only 100 feet of hose instead of the 200 feet. Kinks, kinks are everybodies problem. My firefighters had better not pass up a kink as they walk up a line, whether it is a supply line or attack line.
We use a rule of thumb friction loss, 1-1/2 is 30 psi per 100, 1-3/4 is 20 psi per 100, 2-1/2 is 10 per 100 and 3 is 5 per 100. this makes it easier for the pump operator to develope operating pressures faster. All our nozzles are constant gallon flow nozzles whether fog or smoothbore.
Just a little info for the brothers! Take care, be safe.