Our Fire Chief recently purchased a single shut off 2.5 inch 100 psi Saber Jet Nozzle which has not been put into service. Our facility will, in the near future, be bringing an inline fire pump online to charge the fire protection grid. Pressure at the tip is expected to be around 100 to 120 psi. If the nozzle man is flowing the nozzle on the fog setting and switches over to the smoothbore setting, will the nozzle reaction be too much for him to handle? Are there other things he should be concerned about? I don't have any experience with SB nozzles so any help would be appreciated.
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Guess they are out there, but I have never seen a 2 1/2" nozzle pumped at 100psi unless it was attached to a deck gun and/or ladder pipe.
1 3/4" yes, 2 1/2" no."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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please tell me the size of the orifice on the saberjet, they are typically 7/8, 15/16, 1" and possibly 1 and 1/8". that is very tell tale of the reaction force.
depending on the flow, the friction loss in the hoses will occur dropping the nozzle pressure (all dependent on the flow). also what is the length of fire hose used.
once we find the orifice size, length of hose, and outlet pressure then i can help you.Originally Posted by madden01
"and everyone is encouraged to use Plain, Spelled Out English. I thought this was covered in NIMS training."
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Reaction force on a solid bore nozzle is - 1.5 x Nozzle Diameter squared times nozzle pressure. So a 1" nozzle at 50 psi nozzle pressure is 75 lbs. That 1" nozzle at 100 psi will have a 150 lb. reaction. For the fog nozzle the reaction force is almost 1/2 the gpms being delivered so a 250 gpm fog on straight stream has a reaction of 125 lbs. Since switching from 250 gpm fog to a 1" solid bore will cause an increase in flow, you will get slightly more friction loss in the hose, thus cutting the potential 300 gpm flow back to around 275 gpm and the reaction force back from 150 lbs to around 137 lbs. You don't specify the stationary pump pressures being supplied to the system nor the length of 2 1/2" hose attached to the hydrant or standpipe, so exact calculations are impossible. My best guess is above.
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Originally posted by emtiv1998 View PostOur Fire Chief recently purchased a single shut off 2.5 inch 100 psi Saber Jet Nozzle which has not been put into service. Our facility will, in the near future, be bringing an inline fire pump online to charge the fire protection grid. Pressure at the tip is expected to be around 100 to 120 psi. If the nozzle man is flowing the nozzle on the fog setting and switches over to the smoothbore setting, will the nozzle reaction be too much for him to handle? Are there other things he should be concerned about? I don't have any experience with SB nozzles so any help would be appreciated.
As for the handling question, considering that the NP for fog is twice that for the smoothbore, I'd imagine that there is a good chance that nozzleman could have trouble if the pump discharge pressure isn't reduced correspondingly.
Since you say it's a 2-1/2 nozzle, hopefully your tip insert is greater than 1" instead of only 7/8" like on our new 2-1/2 nozzle. I asked the person responsible for that selection if this was a mistake and was told that it was not a mistake. He didn't seem to think it was a problem that our small handline nozzles had bigger orifices (15/16 and 1") than the 2-1/2 (7/8").
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Originally posted by Bones42 View PostGuess they are out there, but I have never seen a 2 1/2" nozzle pumped at 100psi unless it was attached to a deck gun and/or ladder pipe.
1 3/4" yes, 2 1/2" no.
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Originally posted by emtiv1998 View PostOur Fire Chief recently purchased a single shut off 2.5 inch 100 psi Saber Jet Nozzle which has not been put into service. Our facility will, in the near future, be bringing an inline fire pump online to charge the fire protection grid. Pressure at the tip is expected to be around 100 to 120 psi. If the nozzle man is flowing the nozzle on the fog setting and switches over to the smoothbore setting, will the nozzle reaction be too much for him to handle? Are there other things he should be concerned about? I don't have any experience with SB nozzles so any help would be appreciated.
The nozzle has a 1" smoothbore tip;
The fog nozzle markings indicate it will flow 135 gpm at 100 psi (which I know is a crappy flow rate for a bigger line);
I'd estimate the hose lay will be between 50 to 100 feet of 2.5;
The pumps are stationary fire pumps to charge the fire protection grid. I don't anticipate anyone being there to adjust the pump output. I suppose you could gate it down from an appliance at the hydrant if you switched from a fog to a SB but really don't see that happening.
Hope this helps and thanks for the feedback.
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Originally posted by emtiv1998 View PostA little more information:
The nozzle has a 1" smoothbore tip;
The fog nozzle markings indicate it will flow 135 gpm at 100 psi (which I know is a crappy flow rate for a bigger line);
I'd estimate the hose lay will be between 50 to 100 feet of 2.5;
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Originally posted by emtiv1998 View PostOur Fire Chief recently purchased a single shut off 2.5 inch 100 psi Saber Jet Nozzle which has not been put into service. Our facility will, in the near future, be bringing an inline fire pump online to charge the fire protection grid. .
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We have one of these nozzles on a front trash line and everyone hates it. I personally don't like them for the simple fact that they pretty much take every basic nozzle handling technique and throw it out the window. No more all the way open, all the way closed. No more right to fight. Unless you are trained on them extensively, they are an accident waiting to happen.Career Firefighter
Volunteer Captain
-Professional in Either Role-
Originally posted by Rescue101I don't mind fire rolling over my head. I just don't like it rolling UNDER my a**.
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Originally posted by emtiv1998 View PostA little more information:
The nozzle has a 1" smoothbore tip;
The fog nozzle markings indicate it will flow 135 gpm at 100 psi (which I know is a crappy flow rate for a bigger line);
I'd estimate the hose lay will be between 50 to 100 feet of 2.5;
The pumps are stationary fire pumps to charge the fire protection grid. I don't anticipate anyone being there to adjust the pump output. I suppose you could gate it down from an appliance at the hydrant if you switched from a fog to a SB but really don't see that happening.
Hope this helps and thanks for the feedback.
At 100 Psi 280 solid(SB)/135 gpm Fog. These nozzles switch easily from SB to fog but you WILL find a reaction going from Fog to SB at 100psi supplied. T.C.
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I bought some for my vollie department to put on our brush truck with a CAFS skid. It gives us some options with straight water, as well as the smooth bore for CAFS.
To be honest, I think that's about the only application I'd use one. We use TurboJets on our 1 3/4" lines and Assaults ([email protected]) on our 2 1/2" fogs.
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Cracks you up? I don't understand why! For certain applications, I wouldn't use a solid bore, unless I wanted to spread the fire. Ever try to control a refined petroleum product fire with a straight stream? Didn't think so! In some cases I still prefer a "Low velocity" fog application. Oh we are modern and there is no reason to trust that old "Navy Nozzle"
2 1/2" line on a blitz is exactly correct if you want to use both a blitz at 400 gpm and a 1 3/4" at 180 gpm. And you can supply them both from a 3" tank to pump line (580 gpm).
Cracks me up!
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Originally posted by KuhShise View PostCracks you up? I don't understand why! For certain applications, I wouldn't use a solid bore, unless I wanted to spread the fire. Ever try to control a refined petroleum product fire with a straight stream? Didn't think so! In some cases I still prefer a "Low velocity" fog application. Oh we are modern and there is no reason to trust that old "Navy Nozzle"
2 1/2" line on a blitz is exactly correct if you want to use both a blitz at 400 gpm and a 1 3/4" at 180 gpm. And you can supply them both from a 3" tank to pump line (580 gpm).
Cracks me up!
but, as a matter of fact, for any "outside" fire, including what you mentioned, I have no reservations about using a fog nozzle.
A fog nozzle on a 2.5 or a master stream is not a good choice for obvious reasons. Do I need to tell you why? you looking foolish with a fog on your master stream will not only keep you there longer, but you'll crack me up with how foolish you look.
When did I say I want to use the blitz at 400?, I want to use it at what it's intended. a 2.5 feeding a blitz still cracks me up...do you like to use things for their potential, or settle for less? hint hint
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