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Perhaps someone might know these formula's??

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  • Perhaps someone might know these formula's??

    I've been looking everywhere, but can't seem to find the formula's/equations for things such as... friction loss, GPM output given a specific nozzle diameter/PSI... all that fun stuff. If someone might know any of these formula's, or perhaps even more, I would be most thankful if you could help out.

  • #2
    The best place is a pumps or hydraulics book. I had a ? on calculating pressures for stacked tip nozzles and that is where I found it...for some formulas posted here in forums, check out the stacked tip topic...hope this can help.
    Keep Safe!


    • #3
      Usually these values are taken as some what an estimate, If you are realy serious about knowing what the ammout is write me back and I will try to help. You will need to know the coefficient of friction for the nozzle along with some other factors. write me back at my personal adress if you need more help. A good hydraulics book is sold by fire Protection Publications written buy Pat Brock. He is a Hydraulics professor at Oklahoma State University and realy knows what he is talking about. If you need more help let me know
      let me know if im not clear



      • #4
        the ifsta driver/operator book has a whole chapter on figuring friction loss and different formulas to use.


        • #5
          The formulas are standard and regarding hose, you need to contact the manufacturer and find out what it is for a particular hose. They are different depending on materials used in construction and the construction itself.

          FL = Friction Loss
          NP = Nozzle Pressure
          NR = Nozzle Reaction
          Q = flow rate in hundreds of gpm divided by 100
          L = hose feet in hundreds of feet divided by 100
          C = friction coeffecient
          • 1" = 150
          • 1.5" = 24
          • 1.75" = 15.5
          • 2" = 8
          • 2.5" = 2
          • 3" with 2.5" couplings = 0.8
          • 4" = 0.2
          • 4.5" = 0.1
          • 5" = 0.08
          • 6" = 0.05
          Friction Loss

          FL = C x Q sq. x L

          Smoothbore Flow

          GPM = 29.7 sq. x dia. of the orifice x sq.rt of the NP (pitoted)

          Fog Flow

          GPM = Rated Flow divided by sq rt of rated NP X sq rt. of NP
          It's only my opinion. I do not speak for any group or organization I belong to or associate with or people I know - especially my employer. If you like it, we can share it, you don't have to give me credit. If you don't, we are allowed to disagree too (but be ready to be challenged, you may be on to something I'm not). That's what makes America great!


          • #6
            If you have Microsoft Excel (5.0 through 2000) go to:

            It's the same spreadsheet I use when I come back with my indepth responses

            One of these days I'll figure out how to make a run-time executable out of it so you don't need Excel, but that may be far, far away!
            IACOJ Canine Officer


            • #7
              Another good source for basic hydraulics is at the Task Force Tips website. It explains nozzles and hydraulics. They'll even send you literature on same or you can download it there. They are great and have a good website.


              • #8
                OLD Stand-by Trick

                but don't tell anybody you heard from me...

                Use the THUMS school of fire fighting..
                THUMs up mo water
                THUMS down mo less water
                and the classic call over the radio from the IC SHUT DOWN that LINE
                N O W !!!!!!

                and you have 5 lines working at that time...

                The Real art as a Driver,..is to know who's on what line when the call comes out give me more psi...

                who's on first, what's on second,
                and I don't know third base...

                good luck

                [ 07-28-2001: Message edited by: Captain 12 ]


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