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Friction loss with Combat Hose

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  • Friction loss with Combat Hose

    Good morning,

    In March my department is planning on running some friction loss and GPM output tests with PONN Conquest combat hose (this is the hose we carry on our apparatus). We have done some digging and are pretty sure that we over pressurize our lines. We have been using old friction loss formulas used on old hose. I contacted the hose manufacturer and discovered that we were correct and have been over pressurizing. Although all the studies given used a smooth bore nozzle. Has anyone done any friction loss studies on PONN Conquest line (1.75, 2, and/or 2.5 inch) while using a Fog Nozzle? Thank you in advance for your input.

    Clearwater301

  • #2
    The type of nozzle has NOTHING to do with friction loss in the hose. Friction loss in the hose comes from gallons per minute flowing. The only thing affected by your type of nozzle will be the engine pressure. The example is just for example you are flowing 150 gpm in your lines at 35 psi friction loss per 100 feet, if you are using a smooth bore you add 50 to your friction loss for your engine pressure. Depending on the combination nozzle you may be adding 50, 75 or 100, depending on what the nozzle is designed to operate at, to the friction loss to determine your engine pressure.
    Crazy, but that's how it goes
    Millions of people living as foes
    Maybe it's not too late
    To learn how to love, and forget how to hate

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    • #3
      Originally posted by FyredUp View Post
      The only thing affected by your type of nozzle will be the engine pressure.
      How easy the hose kinks also has a direct relationship to the nozzle pressure, so the nozzle may have nothing to do with FL, but it is a factor that may be important to consider, and it is pretty easy to check all of these things in a single "test" session.

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      • #4
        Originally posted by RFDACM02 View Post
        How easy the hose kinks also has a direct relationship to the nozzle pressure, so the nozzle may have nothing to do with FL, but it is a factor that may be important to consider, and it is pretty easy to check all of these things in a single "test" session.
        A kink in good quality hose generally is not the fault of the hose. It is the fault of a lazy or inefficient hose team that doesn't kick kinks.

        Kinks are not an inherent friction loss hose design issue.
        Crazy, but that's how it goes
        Millions of people living as foes
        Maybe it's not too late
        To learn how to love, and forget how to hate

        Comment


        • #5
          Originally posted by FyredUp View Post
          A kink in good quality hose generally is not the fault of the hose. It is the fault of a lazy or inefficient hose team that doesn't kick kinks.

          Kinks are not an inherent friction loss hose design issue.
          Some has to determine it's "GOOD QUALITY HOSE" ... I guarantee the hose team works harder to minimize kinks when the the nozzle pressure is 50 psi vs. the same hose at 100 psi. With staffing as poor as most of us see, we need to our equipment to work for us vs. against us, hence testing the kinkability of hose through the expected parameters.

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          • #6
            Originally posted by RFDACM02 View Post

            Some has to determine it's "GOOD QUALITY HOSE" ... I guarantee the hose team works harder to minimize kinks when the the nozzle pressure is 50 psi vs. the same hose at 100 psi. With staffing as poor as most of us see, we need to our equipment to work for us vs. against us, hence testing the kinkability of hose through the expected parameters.
            The problem the majority of times when it comes to hose is a penny pincher in the process, whether the Chief, or head of the procurement department for the FD. They low bid hose and end up with hose that is flimsy garbage that kinks, whips, and is virtually impossible to use in the normal manner we use hose. In other words you can't push the hose out in front of you to do the up, down, all around move because it will kink, fold back and hit you in the face.

            Its pretty easy to determine good quality hose. TEST IT. Set a standard for performance and stay with that. GPM at REALISTIC friction loss figures, kink resistance at YOUR normal nozzle pressures, drag ease and resistance to damage. Any vendor that won't lend you hose to test is immediately eliminated from the purchase process. We set standards for so many other things why not hose?
            Crazy, but that's how it goes
            Millions of people living as foes
            Maybe it's not too late
            To learn how to love, and forget how to hate

            Comment


            • #7
              We just tested pon conquest attack line coupled with Chief 50 psi adjustable break away tip w 7/8 slug tip. The line was really good about not whipping, with the fog tip we got 150 gpm with 90-95 PDP. Remove the tip and flow went to 170.
              Our current setup is 100 psi turbo jets on standard 1.75, we get 150 [email protected] 170 PDP. The nozzle reaction on the chiefs was of course much less. The chiefs did not have as much reach or hitting power,.. all relevant to stream velocity. The chiefs did not seem to induce as much air when using fog patterns.
              I liked the hose quite a bit, the actual inside diameter was 1.82, it did not kink nearly as bad as our current line but they were still there... Working the bale did remove most of them.
              Get the first line into operation.

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              • #8
                On the chiefs reach, it was only about 10' less in an open parking lot so probably not going to be an issue in a building. The straight stream had more cohesion.. looks more like a solid stream.
                Get the first line into operation.

                Comment


                • #9
                  Originally posted by L-Webb View Post
                  On the chiefs reach, it was only about 10' less in an open parking lot so probably not going to be an issue in a building. The straight stream had more cohesion.. looks more like a solid stream.
                  My volly FD has been using 200 at 75 Chiefs for quite a while now and we haven't really notice any loss in performance. Like you maybe a hair less reach. I do agree that the straight stream appears more like a solid stream.
                  Crazy, but that's how it goes
                  Millions of people living as foes
                  Maybe it's not too late
                  To learn how to love, and forget how to hate

                  Comment

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