1. #1
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    Default Thoughts Concerns on Automatic Nozzles

    Hi guys,
    I was wondering what your thoughts or concerns are about automatic nozzles. So, far the only advantage I can come up with is that is that at low GPM it LOOKS like a good stream but its not giving you the required GPM. Seems like the disadvantages are many! Plus, how much GPM are you flowing if you don't have a flowmeter on your panel. Most of our calculations are either based on GPM or PSI.

    We have several in service along with some fix gallonage nozzles. I'm thinking.......why keep these automatics on my engine?

    Whats your take on them and am I missing something or are they useless, in so many words.

    Thanks,
    Scottsfire

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    I wouldn't call them useless at all. Automatic nozzles are designed to regulate the tip pressure to a set amount of force. Typically this is 100 PSI. As you force more water into the nozzle, the baffle pushes open allowing more water to come out while maintaining that 100 PSI. Conversley, as water flow reduces (kinks, elevation, reduced pump pressures) the baffle closes to limit the flow since it is trying to maintain 100 PSI. This is the reason you get a great looking stream at very low flows. I would call that a disadvantage personally.

    A trained eye can tell if any nozzle is flowing a resonable amount of water, as will the amount of backpressure (reaction).

    The supporters of this type of nozzle believe that it offers you the ability to have alot of water available and alot of flexibility in flow ranges without having to change tips and nozzles etc. I will agree, but still am not a big fan of them. Unfortunately, unless you train your pump operators on the way they work, you'll ususlly have poor results when it comes to the flow at the tip.

    Not all automatics are created equal either. TFT incorporates a design called a slide valve, which is radically different than the typical ball valve. It allows turbulence free performance at any position of the bale, whereas a ball valve style shutoff offers alot of breakup and turbulence if it isnt opened all the way. TFT holds the exclusive rights to this design, so Elkhart and the others wil not feature this valve design.

    A common theory with an auto nozzle is that you pump it for max flow and use only the water you need (gate the bale back). With any 100 PSI tip pressure nozzle, you add alot of reaction force which makes handling difficult. Teach your men how to handle the lines flowing 150 GPM and more and you wont have to worry about them being lazy and gating the nozzle back while fire consumes the world around them. Some of todays auto nozzles come at lower tip pressures, this wil alleviate some of the reaction force.

    Regardless if you use a fixed GPM, auto or selectable gallonage nozzle, the tip pressure and flow will determine reaction force. Automatics dont make the line any harder to hold onto. 150 GPM at 100 PSI still equals abour 102 Lbs of reaction, whereas 160 GPM at 50 PSI is about 79 Lbs of reaction.

    With fixed gallonage nozzles, you will see better results in reduced flow situations (low pressures) if you have the right tip. A 200 GPM @ 100 PSI fixed gallonage nozzle actually performs well over a wide range of pressures and can deliver alot of water even at 50 PSI. Selectable gallonage nozzles offer the ability to cheat a little extra water out of the tip if you have a higher flow setting, even if the pump operator doesnt increase the flow.

    Another issue is cost. You'll pay alot less for fixed or selectable's as opposed to automatics. Automatics also tend to need regular lubrication, which not many places do. Without maintenance, they will lose their accuracy and may not flow the correct amount of water.

    The bottom line is to understand your equipment and train on it. It all works, as long as ya use it right.

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    A side note: One of the makers, in their catalog, say they are not reccomended for handlines.

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    Originally posted by MG3610
    Regardless if you use a fixed GPM, auto or selectable gallonage nozzle, the tip pressure and flow will determine reaction force. Automatics dont make the line any harder to hold onto. 150 GPM at 100 PSI still equals abour 102 Lbs of reaction, whereas 160 GPM at 50 PSI is about 79 Lbs of reaction.
    Good post MG3610.

    I'm curious where you got reaction force figures from. According to the TFT supplied chart for the Mid-Matic, it has 78 lbs. of reaction on a 200' 1 3/4 line flowing 151 GPM. I've always felt it was higher than that.

    I'm also not a fan of these nozzles because of, as Scottsfire stated, the potential for having a good looking stream that has pitiful GPM.

    Good thread and I'm looking forward to more discussion.
    FTM-PTB-DTRT

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    It really isn't that hard with an automatic nozzle.

    If the gpm you currently have selected isn't enough, open the bail a little more. Little fire, little water. Big fire, big water.

    And then of course you run into the problem where an inch and three quarter isn't enough, then you go to the bigger guns.
    Last edited by fdmhbozz; 05-13-2005 at 08:34 PM.
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    Originally posted by WTFD10


    Good post MG3610.

    I'm curious where you got reaction force figures from. According to the TFT supplied chart for the Mid-Matic, it has 78 lbs. of reaction on a 200' 1 3/4 line flowing 151 GPM. I've always felt it was higher than that.
    You were closer than I was. I did that off the top of my head and mixed up the numbers. My bad!

    Should be for 100 PSI tip pressure at 150 GPM a reaction of 76 LBS. For 50 PSI tip pressure a reaction of about 60 Lbs

    Data from Akron Brass Website.

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    Thanks although I'm disappointed your number's weren't correct It would have been one more point to use with my Chiefs in my efforts to get some smoothbores and 75 psi combos on our engines
    FTM-PTB-DTRT

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    Ive used solid bore, fixed gallonage, adjustable gallonage and automatics. All have advantages and disadvantages. And Im not going to get into a debate over which is better (again).

    The department I work for now has used TFTs since 1985. Never any real problems. All the engineers are used to pumping with them as are the crews with flowing them. They seem to work fine.

    I like the abillity of gateing back and not loosing your stream. It also makes the engineers job a bit easier, as all you really have to worry about is one pressure. The crew operating the line controls the amount of water.

    The one downside is you have to maintain them, cleaning and lubrication is a chore. This must be done, or they will malfunction over time.

    They (TFT) are real good as far as service and repairs. We had the TFT rep out a couple years ago to demo the Blitzfire. While he was here, he ran all our nozzles (even the original 85s) through his test equipment and all but one still flowed per factory specs. The one that didnt he took with him and they rebuilt it for free.



    BTW, I would rather use a solid bore
    Last edited by Dave1983; 05-14-2005 at 04:29 PM.
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    If I remember my history correctly, automatics were first developed to aid in aerial master streams. A chief noticed that each time he needed to flow more on his ladder pipe, he needed to detach another smooth bore tip. The automatic was developed to have a good stream no matter what psi and could give a range of gpms.

    When automatics were first used for handlines, fixed gallonage or adjustable gallonage nozzles were very sensitive to the correct psi. For example, if you flowed a 100psi nozzle at 75psi, it would give you poor stream with poor reach.

    Today's fog nozzles are more tolerable. For example, after extensive testing, we just switched to a fixed gallonage nozzle which flows 200gpm at 75psi. Those numbers give us a great stream with great reach. The same nozzle at 50psi will give you 165gpm with the same stream and reach. This will be our initial pressure for interior attack. We feel it is a good flow with low reaction, however we can still kick it up if more is needed.

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    Here is the history of the automatic nozzle as told to me. The first automatic nozzles were designed and manufactured by Clyde McMillan (TFT). He was the Chief of an auxiliary task force in the city where he lived, which escapes me right now, that supplied master streams to the local FD. Since they had no pumping apparatus they couldn't control the amount of water or pressure supplied to them and at times their streams were ineffective and looked terrible because of this. He designed the nozzle to give an effective looking stream until it could become adequately supplied and then become an adequate firefighting stream. If this is historically inaccurate I apologize, but again, this is how it was told to me.

    Anecdotal story about TFT's. I was at a fire school where an instructor had a 50 foot 2 1/2" line laid from an engine to simulate a standpipe connection. he connected a flow meter and a gated wye to the end of that hoseline. He then connected 100 feet of 1 3/4 inch hose to the wye. he placed a dual force nzzle on that line and had the pump oerator throttle up until there was 45 psi at the wye. Attempting to simulate a pressure reducing fitting on a standpipe discharge outlet. With the nozzle set on 100 psi we got an amazing 13 gpm' from that line. We switched it to low pressure and gained (sit down this may shock the heck out of you) an unbelievable 1 gpm to flow a total of 14 gpm. Oh the stream had reach, 70 feet or so. But not enough flow for anything beyond a waste basket. We replaced the TFT with a 15/16" smoothbore and flowed 118 gpm to a distance of about 40 feet or so. Okay you tell me, 14 gpm for 70 feet or 118 for 40 feet? Which line do you want crawling down that hallway?

    The other problem with any automatic is the tendency amongst firefighters to gate the nozzle back anytime an attempt to flow over 150 gpm's is made. Nozzle reaction and the constant preaching of the salespeople that you control the flow at the tip has created the "I'll only flow as much as I feel comfortable with and not necessarily enough to do the job firefighters."

    If they work for you terrific. I'll stick with my low pressure, high flow combination nozzles and smoothbores.

    FyredUp

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    We pump our engines at 200 psi. The chiefs reasoning is that with the friction loss of the lines, that pump discharge pressure gives sufficient nozzle pressure. If you can't hold the nozzle at that pressure, you won't be on the knob.
    -Bozz

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    bozz.............I am not so sure that is a good rule of thumb .......maybe for a 1 3/4 or a 2. 5 .......but that would need an ape or few on that. We have a variety of automatic and fixed gallonages and a 2.5 lightweight smoothbore blitz line. The auto matica tell you right on there what psi = what gpm.
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    We use 1 3/4" Hi-Combat II, which is actually a lot closer to 2".
    -Bozz

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    FyredUp,

    You are right about the automatics. It had been a while since I had heard the story, but thats it.

    Bozz, if you are pumping 200ft of Hi-Combat at 200psi, you are probably over-pumping it. Hi-Combat is an excellent hose and has low friction loss. For a 100psi nozzle at 150gpm, the rule of thumb is 70psi friction loss on 200ft. I do not know what friction loss is in your pump, but I would imagine you are probably getting 130-150psi at your nozzle. Thats a lot of nozzle reaction for the guys on the end of the line. Everyone has their own ways, and if it works for you thats great, but its just something to consider.

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    We run through 150', and at full pressure, I can hold the nozzle all by myself, and I am by no means a big guy.
    -Bozz

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    We used a flow meter. TFT Automatic through 200' of 1 3/4" Ponn hose, pumped at 170psi gave us 150gpm. Screw theories and calculations, use a meter.

    PS - the nozzles had not been serviced in over 10 years. Akron salesman bet me a nozzle the TFT wouldn't flow correctly. Now I have a shiny new Akron.
    "This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?

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    What's better than a new nozzle? A FREE one!
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    Bozz...I'm guessing you guys never have to worry about kinks do ya?

    I want to flow the most GPM possible at the lowest PDP possible.

    I like Spencer534's idea of underpumping and still getting a great flow. Spencer, can you post the make and model number of that nozzle?
    FTM-PTB-DTRT

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    I don't ever remember having a kink.
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    Wow..........I should have used this forum in our shift training discussion. What a ton of great information and experience with each of the different kinds of nozzles. Find most of it a little "information overload" but when I get off shift tommarrow morning and go home I'm going to log on an start to analize all of this stuff.
    I will tell you this...........this thread has been more than educational for me. Thanks again guys for sharing your experience with those of us that have little experience in the seat with the wheel.

    Now if you will excuse me....I've got a automatic nozzle on my rig that I'm sure hasn't been cleaned or lubricated in 5 years!

    Scottsfire

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    WTFD10,

    The nozzle is an Akron Assault 200gpm @ 75psi tip (I can't remember the part number at this time) attached to a bail/shutoff with a 15/16 smoothbore. We can take the tip off and extend the line or go go big water with the smoothbore. Let me know if you need more info.

    Spencer

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    The 15/16's at the standard 50psi is 183 gpm as opposed to the 200gpm combo at 75psi. Are you overpumping the 15/16's and at what pressure?

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    oldman21220,

    We pump the smooth-bore at 50psi when we take the tip off and get the 183gpm you were talking about. From there we do overpressure it to 80psi (that's the highest we've tried) and got 230gpm. While this is some increase in gpm over the fog tip it is a big increase in reach.
    Last edited by Spencer534; 05-20-2005 at 04:52 PM.

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    Originally posted by Spencer534
    oldman21220,

    We pump the smooth-bore at 50psi when we take the tip off and get the 183gpm you were talking about. From there we do overpressure it to 80psi (that's the highest we've tried) and got 230gpm. While this is some increase in gpm over the fog tip it is a big increase in reach.
    Yeah, and I would guess an increase in reaction force as well...

    If I need more then 200gpm, I'm switching over to 2 1/2" hose
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    Must really do a job on sheet rock.

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