Thread: Automatic Nozzles
02-23-2000, 08:55 PM #1StaticPressureFirehouse.com Guest
Having received a new copy of the manual that goes along with our nozzles I am anxious to find out what you think the advantages or disadvantages of Automatic nozzles are.
Disclaimer: The views expressed in this post are purely mine and not that of the department or any associations of which I am a member. They have their own ridiculous views.
Stay Safe and Stay In the House!
03-24-2000, 03:12 AM #2oldrepeaterFirehouse.com Guest
Like you our hall is considering using auto nozzles.
I am a volly but do hydraulics for a living, so I was intrigued by how the auto nozzle worked.
I found that their hydraulic cousin is a "Pressure compensated flow control" and like their higher pressure kin, the one and only thing to keep in mind is that the auto reaction has limits. The spool or slug that moves to compensate for the change in pressure is finite in it's length. Therefore the nozzle will function beautifully within it's operating brackets but once you have exceed those, the nozzle will respond like a "normal" non compensated model.
So I guess what I am saying is like any other piece of equipment know it's limits, know how it works, and apply accordingly.
[This message has been edited by oldrepeater (edited March 24, 2000).]
03-24-2000, 04:50 PM #3NUMBYFirehouse.com Guest
We dont use auotmatic nozzles here, we use smoothbores with a 15/16 tip, but we also have have combination nozzles, i think Akron turbojet, but not positive. We have looked at some automatic nozzles, a neighboring department uses them. The thinkg you have to watch is that, the nozzle will aoutmatically adjust to your pressure and make a nice pattern. They were flowing at like 150 psi, which only came out to like 75GPM's when checked with a flow meter, so if your gonna use them make sure to flow them properly to get a good flow.
Anything left in the forums is my opinion and does not reflect my department or any organization i belong to.
03-31-2000, 12:16 PM #4wv-engineerFirehouse.com Guest
There is one advantage, that is minimal, if you want more water you still have to tell the engineer to throttle up, with an automatic the nozzleman does not have to change the setting as on a select-a-gallonage the nozzle does it "automaticlly"
The major disadvanage is the nozzleman does not know how much water s/he is following, all streams with in the range of the nozzle look good. What is the engineer supplying, a kink in the hose, pinch by a door.
With a selet-a-gallonage nozzle if the pressure is to low the stream looks bad and the nozzleman knows something is wrong, if the pressure is to high all the extra psi go to reaction force.
A good looking stream does not put out fires, GPM does.
One more advantage that I forgot. If your drivers do not know how to do hydraulics, then they will want automatics, becuase they will almost always pump a good looking stream.
This maybe more personal preforance, but the nozzle debate lives on!
04-08-2000, 01:14 AM #5Firstin88Firehouse.com Guest
We use automatic nozzels exclusively, we love them! We will never go back. We use class A foam on everything except class B fires and it works very good. I tend to disagree with the disadvantages listed above. But I guess your last sentance says it all!
Stay Safe and God Bless
04-09-2000, 03:58 PM #6FyredUpFirehouse.com Guest
Well here goes my 2 cents or perhaps it's worth less than that!
Automatic nozzles for the most part do exactly what they are intended to do. They regulate pressure, most to roughly 100 psi, some to roughly 75 psi. As more water and pressure are pumped to the nozzle the spring allows the baffle to open and more water to flow. If pressure and gpms are reduced the spring pulls the baffle back and reduces flow, but maintains pressure.
I agree that the nozzle operator doesn't always know what they are flowing. But I disagree with the concept that a nozzle operator can't discern the difference between 50 gpms and 150 or 200 gpms. If they can't tell, then they need more time on the training grounds. Nozzle reaction will increase with increased gpms.
The biggest problem I have seen with auto nozzles, in my FD and many others, is that people gate the flow to a comfortably managed flow. The exact amount varies with each FF. But my point is this, it makes no sense to plan on 200 gpm flows if your nozzle operator gates the nozzle to a more comfortable to handle 75 gpms. The second problem is pump operators pumping inadequate pressure to meet the planned flow. Correctable problems? Sure, but still reality.
Now, is anything the auto nozzle is doing wrong? NO, it does what it is supposed to do. The choice of what nozzle to use is up to your FD.
But I would ask some questions first: 1) What do you see as the advantage to an automatic nozzle? 2) What gpms do you intend to flow? Not what will the nozzle flow, but what you realistically intend to flow. 3) How will you determine what nozzle will meet your requirements? Flow testing? Catalog data? Salespeople? Don't believe the hype, get flow meters and inline pressure gauges and test what you are looking at. If a salesperson won't let you test their product using flow meters and gauges you have to ask yourself why not?
Now before you figure I am an auto nozzle guy....I am not. My FD uses low pressure 200 gpm at 75 psi nozzles backed with a
1 1/4" slug tip on 2 inch hose. We had auto nozzles and after extensive research and testing we made the change. Am I suggesting you do the same....NO. But test what you are looking at, make sure it will do what you want, in the way you want, before you buy.
Also, I am not now, nor have I ever been a fire equipment salesperson, manufacturer or distributor. I am a firefighter and as such, an end user of fire equipment.
These are my opinions, yours may be different. Have a nice day.
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