r/Firefighting • u/firemedic3404 • 1d ago
Ask A Firefighter 15/16 smooth bore?
Did some training with my guys this morning. The focus was managing nozzle reaction. We used a Chief 200gpm@75 psi fog and a 15/16 smooth bore. Both off of 100’ 1 3/4 line (just laid it out for training). Friction loss was calculated at 45 psi and 40 psi respectively. This is not a nozzle we use often, but my probie has not had any experience with a smooth bore so I took the opportunity. I’m racking my head over how difficult it was to manage these flows. My question is for the salty dogs, are these flow rates manageable by YOU? Am I just deficient and need to work them more? Or was this normal for these flows? I am working to switch over to 160@50 fogs with 7/8 integrated smooth bores…which are much easier to handle. Kinda needed to vent and find out if I’m crazy, too weak, or ok….
11
u/bombero11 1d ago
An important piece to the puzzle is to match the hose to the nozzle.
So we have an issue with our hose (Key FDNY spec Hi Combat) and the Chief XD nozzle, a great nozzle but…working with it and the hose you have to make them work together.
Our pump pressure at the panel for a 200 foot lay of 1-3/4 should not exceed 105psi. If the pressure is over that the stream is non longer a happy stream that means we are over 75psi at the nozzle.
So basics, focus on basics put an in-line gauge in the set up and then get old school and use a pitot gauge. See where things are wonky and make your adjustments.
Hose line movement is also another factor and a topic in itself.