Thread: Automatic Nozzles
05-06-2000, 11:12 PM #1firemedic490Firehouse.com Guest
Our department is currently doing research on automatic nozzles. Please let me know your likes and dislikes. We currently use selectable gallonage nozzles. Please discuss the automatics in relation to selectable gallonage. Thank you.
05-07-2000, 10:50 AM #2FyredUpFirehouse.com Guest
Okay here we go!!
First of all let me state automatic nozzles do exactly what they are designed to do. And....that is to attempt to maintain a predetermined nozzle pressure, whether that pressure is 75 or 100 psi, through a defined flow range specific to that nozzle usually somewhere between 50-200 or 50-350 gpm for handlines. Hopefully we can all agree on that.
Selectable gallonage nozzles also do what they are designed to do. With the nozzle set at a particular flow 30-60-95-125, or 90-125-150-200, or 120-150-200-250, or whatever, the pump operator must pump the proper pressure to meet the flow set on the nozzle. Generally the nozzle is set at one flow to start and if a change needs to be made the pump operator must be notified of the gpm change. If the pump operator is not notified of the chnage simply switching the setting does not gaurantee that the flow will be as set.
Now that we have a basic understanding of both nozzles here is my opinion, REMEMBER this is my opinion.
I have used both types of nozzles and they both work. The real question to be asked here is what is it you are looking to do? Why has the idea of change come up? Is it to increase gpm's? Or are the selectable gallonage nozzles worn-out and need to be replaced?
The reason I ask those questions is part of the problem with nozzle selection is that many times people don't think out what they really want to do. If your intent is to have a nozzle that automatically adjusts flows and the nozzle person can gate to a handleable flow then the auto is the choice. If the selectable gallonage nozzles have worked for you and flow enough water what is the motivation for the change?
My department had selectable gallonage nozzles and when we moved up to 1 3/4" hose we upgraded to automatics to increase flow. (My next statements will open me up to attack and ridicule but I will state them anyway because they are true) What we found was simply this, almost every time the line was pumped to flow over 150 gpm's the nozzle operator gated down the nozzle to have better control. This was not limited to my FD, it included neighboring Volly FD's as well as the large career department close to us. Now of course the nozzle reaction for flows over 150 gpm's would be roughly equivalent in the selectable gallonage nozzle for the same flows at the same nozzle pressure.
There are low pressure automatics on the market, and if your current selectable nozzles have a setting of 200 gpm or more you can operate them as a low pressure nozzle. Set the nozzle at 200 and underpump it to flow 170 gpm at a lower nozzle pressure. Either one of these choices allow higher gpm flows at lower nozzle reaction.
Given the choices you have listed, here is my opinion. If the selecatble gallonage nozzles flow enough water and are in good condition, keep them. If they are reaching the end of their service life or don't flow enough water I would look at a low pressure automatic nozzle.
My FD uses a single gallonage nozzle that is a break apart nozzle the combo tip flows 200 at 75 psi and the smoothbore slug behind that flow 300 at 40 psi. It works for us. Is it what you should do? Only you know what you want to do.
Take care and stay safe,
Others, remember these were only my opinions, yours may differ, but it doesn't have to become another war.
Have a nice day!!
05-07-2000, 03:47 PM #3reddogFirehouse.com Guest
I agree with Don, if the issue is a new nozzle, a good choice would be a 'low-pressure' automatic. Elkhart has a SM 30LP, that delivers plenty of water @ aprox 70,psi at the tip. A flow of 175 gpm with 1 3/4 hose, will give you all thats normally needed for a basic room and content fire.
When the job calls for it the firefighter still has a range higher or lower with good stream quality and gallonage. Exmple, if you pump the nozzle at 75 psi, your gallon per minute is 220, if you pump lower, ie; 60 psi the flow is 87 gpm.
Low pressure nozzles mean more water at less pressure. Automatic/low pressure nozzles are relativity new to the fire service and once a firefighter gets their hands on one, they understand how much easier applying water becomes. All the best to you and your brothers and sisters. Be safe.
05-07-2000, 09:04 PM #4S. CookFirehouse.com Guest
Problems I've encountered with selectable gallonage nozzles -
#1 problem - nozzleman inadvertantly changes the gpm selection when changing the pattern.
#2 problem - Two brand new ones used the other day, took 2 hands to adjust the pattern because the nozzle head swivels for whatever dumb reason.
#3 problem - diiferent crews set them at different pressures. An aggressive crew bumps 'em to a higher setting so they can fight fire, another sets it lower because they think it's easier to hold.
Admittedly, problem 1 and 3 should be remedied through training. But the nozzles in problem 2 are brand spanking new pieces of crap.
After watching an industrial brigade that gets a limited amount of training fumble with these nozzles, I'll begin working to get their whole stock of nozzles replaced with autos.
05-20-2000, 11:59 PM #5fireresc32Firehouse.com Guest
Recently tried out and did some field testing with the new taskforce automatic nozzles. They were great...Get in touch with the rep in the area he let us borrow the nozzles for close to a week to play with. Try them youll love them.
05-21-2000, 12:14 AM #6FirehoseFirehouse.com Guest
Our Department ment to Elkhart SM's in 1991 and love em. On our last purchase, we bought SM 20 and SM 30 Break a parts giving us the flexiability to go with smooth slug tips for CAFS and automatic combination fog for plain water attack. We chose the following combination of precons: front jump 100 feet 1 1/2 with a 7/8 smooth, upper speedlay 150 feet of 1 3/4 with a SM 20 breakapart. Loweer speedlay 200 feet of 1 3/4 with a SM 20 breakapart. 2 1/2 crosslay 150 feet with a stacktip smooth, 2 inch crosslay with 200 feet and a breakapart SM 30, and rear Blitz line with 250 feet of 3 inch with a SM 30 playpipe.
05-21-2000, 11:15 AM #7resqbFirehouse.com Guest
OK here's my OPINION, and mine alone. I do not like automatic nozzles. Period. If I had the option of a varible gallonage nozzle, or an auto, then the auto stays on the truck. Autos are bulky, and when you are inside and the hydrant pressure hits the rig, and your pump operator or the relief valve fail to do theiir jobs you are coming out the front door in the air. I.E. recently pump operator joked that I briefly had 360lbs. on an 1 3/4 line. Until he got it backed down. Well I knew I had a problem, it sent me across a room with the bale wide open and into a wall. There was no time to close bale down and the difference from 180lbs to 360 isn't childs play boys.
Autos also always have a good stream, too little pressure or too much, it's always tight with alot of throw. If there's not enough presure on a varible gallonage nozzle, you get a crappy stream.
I also have spun the dial on variable gallonage nozzles once, but it would never happen again. I felt the line had stiffened, (from going from 125 gpm to 60 gpm) but I didn't put 2 and 2 together until later, after I had gotten blown out of the room by fire. now I know what changing the setting feels like when it happens by accident.
However, if you do get automatics, please don't get pistol grips. They are bulky, and often get stuck in the crosslay. We pack nozzle in the middle of the lay so it comes out either side I also like to shove the nozzle into the ceiling or attic, and the grip often gets stuck, or doesn't let me work the nozzle back and forth as much.
Whatever you do don't change for the sake of change. Study each nozzle and work with them. Remember, water BTU absorption > fire BTU = knockdown. Make your decision on facts not on my or anyone elses opinion here.
These opinions are mine alone and do not represent the opinions or doctrines of others. Only a few probies were melted in the operations cited .
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