Thread: Nozzles

  1. #1
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    Default Nozzles

    I am currently in the process of trying to update the nozzles in our deparment. We currently have a combination of TFT Midmatic nozzles and old Akron ball valve nozzles on our handlines. I would like to convert to all TFT 50-350 gpm series nozzles for all our handlines. I am meeting resistance from our purchasing agents who state that there is nothing wrong with the old Akron's. They say that they flow water so there is no reason to upgrade them. I need as much information as possible to convince them to upgrade. Addition: We operate 1500 gpm dual stage pumpers. Almost all hose is new (within last 3 years) and is low bid. We use preconnected 150' lengths of 1.75 on crosslays and a preconnected 1.75 200' length off the back. We also use 2.50 inch Ponn Hose for larger operations that is preconnected at 200' but can be extended. Thanks for the help in advance.

    [ 09-08-2001: Message edited by: OakFD703 ]

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    -- What size are your pumps, and two-stage or single stage
    -- What size hose in your handlines and typical lengths used
    -- What pressures are you comfortable pumping lines at

    Gosh, I asked nothing about nozzles?

    1st, mid-matics don't go upto 350gpm. Those are considered the Handline series by TFT.

    They operate at 100psi nozzle pressure (unlike the Dual Force line that can flow 250gpm @ 55psi if you choose)

    At 350gpm, friction loss per 100' is:
    Standard 1.75" 190psi
    Angus Red Chief, Hi-Combat 1.75 118psi
    Ponn Supreme 1.75" 129 psi
    Standard 2" 98psi
    Ponn Supreme 2" 81psi
    Angus Chief 2" 48psi
    Standard 2.5" 25psi

    i.e. if your running low bid or 20 year old 1.75" your need to overcome a friction loss of 190psi for every hundred feet to flow 350gpm.

    For a 150' preconnect of conventional rubber lined 1.75", that's 275psi for friction loss, plus another 100psi for the nozzle -- so you need a Pump Discharge Pressure of 375psi. That's on the high side, and some pumps like a 1000gpm single stage can't generate that volume at that pressure.

    Move up to a good quality 2" like Angus Chief (although that has it's own problems, I hate advancing neoprene!) you could have a 200' length using only 96psi to overcome friction plus 100psi for nozzle, for a PDP of 196psi to deliver 350gpm -- that's easily doable by any Class A pumper.

    In other words, before you even consider buying nozzles, work out the hydraulics and improve your pumps and hose first. Only if they're in order is it time to consider upgrading nobs.

    BTW, when selecting hose either conduct your own tests on your hose to determine it's friction loss, or contact the manufacturer for your hose make/model's specific friction loss. The old tables in IFSTA, NFPA, etc are calculated on hose technology that's been obsolete for two decades.

    Also available if you have MS Excel is my fireinfo spreadsheet at http://www.mortlake.org/Miscfire/FireInfo/fireinfo.htm . It's what I used to whip up the numbers above.
    IACOJ Canine Officer
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    Their may be nothing wrong with your Akron nozzles. You need to find a flowmeter and test the older nozzles. I would personally dump the automatics and switch to something else.
    The selection of nozzles should be based upon your needs. What do you want to flow from your 2.5" lines? If all you want to flow is 250 or 300 GPM and that is what you are getting from the Akron then their is no need to change, unless you want the penetration of a smooth bore. Myself, if I pull a 2.5" I want BIG flows. I would choose a smooth bore or better yet a Vindicator Blitz Attack. It is rated for 325 @ 50. The nozzle reaction is almost nill. Up the pressure and you'll flow in the 400+ range and you will be able to work the line, without a problem.
    While you are testing the Akrons, try testing you TFT's also. You may be suprised at what the nozzles are actually flowing based on your pump charts and sop's.

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    Vindicator Blitz Attack. It is rated for 325 @ 50. The nozzle reaction is almost nill.

    123 lbs of reaction force is nill?

    Yippeee...can't wait till the next time a smoothbore diehard says a 185gpm 100psi Automatic nozzle on straight stream is too hard to handle with it's 93 lbs r.f.
    IACOJ Canine Officer
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    For those that like the Vindicator Blitz Attack, TFT is coming out with a nozzle very simliar. Very high gpm at very low pessure. It should be out shortly, sorry do not have all the details. Was just seen at ICHIEFS in New Orleans. Stay tuned though.
    If it gets too hot for you just go out and wait by the truck.

    Opinions are like *******s, everyone has one and now I have shared mine.

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    Dalmatian90, how did you come up with those numbers for nozzle reaction?

    To my knowledge their isn't any hard fast numbers for the vindicator in relation to nozzle reaction. I'm going purely by feel, and flowing the same gpm the vindicator is much easier to handle than a smooth bore or fog nozzle.

    On a side note if tft has this great new nozzle why isn't it published anywhere?

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    ADSN, the Vindicator Blitz Attack performs hydraulically like an 1-1/4 tip which at 50psi flows 328gpm with 123lbs R.F.

    The formula for a straight stream fog nozzle produces similiar results -- 325gpm, 50psi has 116lbs R.F.

    If you're seeing Reaction forces significantly below these, you'd see a corresponding dramatic drop in the reach of the stream. The key to any nozzle reaction is the velocity water is leaving the orifice -- the higher the velocity, the higher the nozzle reaction. Velocity also relates closely to reach -- to little velocity, the water goes out and drops on the ground -- although other factors come into play at the extreme far side of the reach when gravity, air resistance, wind, heat, etc start affecting the stream.

    For instance, you can flow 328gpm through a 1-1/4" solid bore. It takes 50psi and gives you 123lbs R.F. 325gpm through a 2" solid bore takes 7.5psi nozzle pressure and produces 47lbs R.F. -- not a lot of reaction, but I'm sure we'd agree 7.5psi isn't gonna travel far. 325 through a 15/16" takes 155psi nozzle pressure and produces 214lbs of R.F. -- in all three cases, the flow is the same, what changes is the pressure.

    F=MA which is Force = Mass x Acceleration
    Which is why the same GPM (which ways the same amount) produces different forces as it's velocity changes. Pressure at the nozzle determines how *fast* the water is pushed through the nozzle.

    Fog nozzles set to straight stream have very, very close r.f. given the same flow and pressure as a smoothbore.

    If the actual Reaction Force of a vindicator is significantly below those R.F.s, then the question becomes why? Fog nozzles set to 30 degree patterns have less R.F., and especially those set to 60 degree patterns have less. Two things come into play. First, the nozzle on the wider patterns tend to "block" more of the stream -- instead of the whole stream pushing straight back, some of the forces is being absorbed by the process of breaking up the stream to form a fog. Second, the force isn't all being directed straight back, but starts to vector somewhat against each other -- think of a wide 60 degree fog -- some of that pressure is going up, some is going down, and they help cancel each other out. But as you start to see significant decreases in nozzle reaction, you see significant reductions in nozzle reach.

    Similiar to a fog nozzle on fog pattern starting to drop nozzle reaction as it uses some of the energy to make the pattern, the Vindicator may also have a lower reaction force since the creation of the broken stream might suck up some of the energy.

    If it did have significantly less reaction force since it's using energy from the system to break up the stream, you should see a significant drop in reach of the stream -- unfortunately, First Strike gives their nozzle reach tested at 20 degrees, where other manufacturers use 32 degrees as the test angle.

    I do think 20 degree is probably a more practical angle, but unfortunately it leaves one unable to compare nozzles on a purely "paper" basis. (And in my humble opinion, nozzle reach except for master stream operations is irrelevant to the fire service -- just about any nozzle flowing 150gpm or more has enough reach to go in one side of most non-commercial buildings and out the other)

    Without nozzle reaction force formulas provided by First Strike (they don't on their website anyways), and without evidence to contrary like apples to apples reach comparisons, it is reasonable to assume the physics involved with a Vindicator nozzle is similiar to a smoothbore or straight stream fog. If it is any consolation, since Vindicator is a broken stream device it would be reasonable to use the fog straight stream formula instead -- which would knock the reaction force down from 123lbs to 116lbs -- still a way from nill.

    =====================
    Now, how you perceive reaction force can vary dramatically -- there's a lot of ways to handle it properly and set up hose & layouts to help absorb the force.
    IACOJ Canine Officer
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    The Vindicator can't be compared to any other nozzle "on paper". When I first say the vindicator in real life, (a few years ago) I thought that their was no way that that thing could do what was claimed by First Strike. But after their presentation, SEVERAL drill and some actual incidents I have found that everything reported about the vindicators high flows and ease of use is true.
    The Vindicator works like no other nozzle that I have seen on the market. It puts out a massive amount of water from a line that is easy to use.
    You have to see it to believe it, It also works great for AFFF.

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    Back to the question. The nozzles you have are most likely fine. You need to remember that there is no universial nozzle.We have used Akron, TFT, Vindicator, and smooth bore. They all have advantages and disavantages. What you may need is more of a variety of nozzles. We use 2 TFT dual force on 1 3/4" X 200', 1 Vindicator Heavy Attack on 1 3/4" X 150', 1 smooth bore(15/16") on 1 3/4" X 200', 1 TFT on 2 1/2" X 200', and a smooth bore with stacked tips on 2 1/2" X 200'. I am not saying to use the same as us, but the more "tools" you have the better chance of having the right one

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    at my dept i think we run Akron( i'm not sure) but if you want maximum flow of water run a smooth bore nozzle. Personally i don't like them as much but there's a full time dept near us there slowing replacing them all with smooth bore.

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    If you want to really upgrade you could get rid of the TFT's and keep the 20 year old Akrons.....Really in spite of what nozzle reps may say there is no one nozzle for every application. If you have a staffing problem try low psi fogs and smoothbores, and no, I wasn't paid to say that.

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