1. #1

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    Default fire ground pumping policy

    My department is jumping back and forth right now with our policy on initial pumping pressure for our preconnect lines on residential structure fires. Initially we pumped our trucks to produce 95 GPM, and now our training chiefs are pushing for 150 GPM.. Personally i never had any issues extinguishing our room and content fires with 95GPM, does anyone have any literature or ideas to take back to the chiefs that are either for or against this belief?

    this is on 1 3/4 inch preconnect lines with automatic fog nozzles by the way.

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    Well, using the estimated fire flow for 40'X30' home 25% involved (((LXW)/3)*% involved) give you ((40x30)/3*).25 which is a estimated flow of 100 gpm.

    That makes your 95 gpm just sufficient according to the textbook. Not saying that you won't be able to put the fire out with 95 gpm, but why not have the extra water and knock it quicker.

    My last department would flow 200 gpm through 1 3/4" hose. Current department flows about 150.

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    You may have to do some math. Check to see the GPM of your nozzle. Then figure out the fiction loss on your pre-connects and see what you need to pump to get the right GPM for your nozzle. Hope this is a start.

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    were running 120-150. It's not going to hurt to have more water.

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    Can of worms coming here I predict...

    Take away all the opinions on fire flow formulas, GPM'S vs BTU'S, narrow vs fog, adjustable gallonage vs smooth bore vs fixed rate, and do your own flow meter testing. Play with different nozzles, streams, hose sizes etc.

    We just recently switched to a new (to us) nozzle and found that the new way was much better. The old 125gpm adjustable nozzle with 100PSI NP was putting out 90-100gpm due to age, wear and tear, friction loss etc. The new nozzles are 50PSI NP and putting out 150-180 GPM depending on using the fog tip or breaking it off to use the straight stream. Simply said, more water, less pressure. Less pressure means less wear and tear on your pump.

    You're correct, you can put out alot of fire with 95gpm set ups. But if you're not increasing any pump pressure/wear and tear AND putting out 1 1/2 to almost 2 times the amount of water....why not do it? As PGFD said, more water won't hurt you. In fact, you might be surprised at how much MORE fire you can put out faster.

    Do your own testing.

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    58% more water with a little bit more work for the nozzle man. Better to have extra than not enough

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    Default Pressure

    150 psi sounds fine. That's the starting pressure we used. If it's too much you can always drop it to what ever is comfortable for your nozzelman. The saying goes....raise the pressure until your nozzelman just about comes off the ground and back off a bit. LOL
    Respectfully,
    Jay Dudley
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    Why not do both?

    Since your preconnects are a set length with a set nozzle you can figure out any number of flows and record the results. Mark your discharge gauges for two different pressures so you always know where you want to be.

    I have ours marked with a black line about 30 psi less than max for minor stuff, and a red line to signify maximum flow at 200 GPM on the 1 3/4. Do not exceed red line.

    95 GPM is pretty low for a 1 3/4. 150 sounds much better. How much flow can you get out of the automatic nozzle you have? You may want to figure out the max performance of the hose and nozzle and keep it marked on the discharge gauge for those times when you need maximum performance. Marking the gauge makes it easy for a substitute pump operator who may not have those numbers in his head when he is in a hurry.

    Alway verify flows with a flowmeter. Friction loss calculations are good if they are right. We have Key hose, and the numbers given by them are not right. The hose performs better than what they say so if I went by their numbers I would be overpumping our 1 3/4 by about 40 psi. I'm not sure how far over the 200 GPM target I would be, but it would make the stream quality go to hell and beat up the crew.

    Flowmeters are priceless.
    We do not rise to the occasion. We fall back to our level of training.

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    Quote Originally Posted by YFDLt08 View Post
    Can of worms coming here I predict...

    Take away all the opinions on fire flow formulas, GPM'S vs BTU'S, narrow vs fog, adjustable gallonage vs smooth bore vs fixed rate, and do your own flow meter testing. Play with different nozzles, streams, hose sizes etc.

    We just recently switched to a new (to us) nozzle and found that the new way was much better. The old 125gpm adjustable nozzle with 100PSI NP was putting out 90-100gpm due to age, wear and tear, friction loss etc. The new nozzles are 50PSI NP and putting out 150-180 GPM depending on using the fog tip or breaking it off to use the straight stream. Simply said, more water, less pressure. Less pressure means less wear and tear on your pump.

    You're correct, you can put out alot of fire with 95gpm set ups. But if you're not increasing any pump pressure/wear and tear AND putting out 1 1/2 to almost 2 times the amount of water....why not do it? As PGFD said, more water won't hurt you. In fact, you might be surprised at how much MORE fire you can put out faster.

    Do your own testing.
    What kind of nozzles are you using?
    FF/Paramedic

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    Quote Originally Posted by TNFF319 View Post
    What kind of nozzles are you using?
    black and orange ones.


    seriously, though, they are Elkhart Brass Chief line, on 1 3/4 hand lines, break apart nozzles. I'm currently drawing a blank on the exact model number, and couldn't find what I wanted on Elkhart's website. But that is the general ball park.

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    95 GPM intital fire flow is a joke. Just flow 150 and be glad you had the "extra" water when you needed it. IMO 150 should be the starting point for a house fire.

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    I don't get the "starting" pressure vs. full flow. Why not flow your target gpm and if it's not enough, get a bigger line? How do you evaluate when 95 or 125 is not enough and add only 50 gpm more? Flow what your FD determines to be the proper flow for the nozzle and use that to determine the effectiveness of you attack. We shoot for 180 gpm with SB's and 160 on the 100 psi fog nozzles. The only nozzle we might consider upping the psi for more water would be the Vindicator which has a much greater range of flows with little difference in reaction force, and that would only be in the event pulling another line would take to long or cannot be done simultaneously.

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    Quote Originally Posted by RFDACM02 View Post
    I don't get the "starting" pressure vs. full flow. Why not flow your target gpm and if it's not enough, get a bigger line?
    I agree... Why start low when you start at the top and then throttle down after knockdown. I've never flowed test our preconnects but pump our 200' footer at 170 psi. Never once during a fire has my crew or any of the others guys complain that was to much. Now stick them out in parking lot standing up flowing water at that psi and they'll **** and moan until it's back down.

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