Fire Engineering Training Community

Where firefighters come to talk training

Hey brothers, I am just wondering what kind of target flow you have for your 1 3/4-inch or 1 1/2-inch attack lines. The department that I belong to currently uses 1 3/4-inch hose lines, 55/100 psi automatic nozzles with a target flow of 100 gpms. I have been trying to convince the powers at be to up our flows, but have not won that battle yet. With that said, I have my crew flowing a 180 gpms at 55 psi NP. So tell me, what is your target flow?

Views: 2380

Replies to This Discussion

Our target flows are 150 GPM with TFT nozzles, and 180 GPM with 15/16" smoothbores. The problem is that the TFTs are 100 PSI nozzles, so the pump operator needs to be on the ball. We use smoothbore 2 1/2" nozzles, and we start out at 250 GPM.
The biggest question is to ask the Chief of the Department what his target flows are for 1 3/4" and 2 1/2" hose. I bet most don't even think of the question!
Right now we use the Akron Assualt nozzles with a break apart and a slug tip. 15/16" for the slug tip and a 150/50 combination tip. So I guess our minimum is 150 gpm with 1 3/4" hose. I use only the solid tip for interior operations so I guess my personnal minimum is 185 gpm. What are you using for a backup line if your target flow is 100 gpm?
Hey Bob, our back up attack line would be another 1 3/4" hoseline flowing 100 gpm. That is why I teaching as many people that is willing to hear me, that we must up our flows. I have not given up the fight yet... One day I hope to announce to all of the Brothers here that I won my battle, till then, please keep sending me this great information. -Aloha
Is it just me, or are we just preaching to the chior on these blogs?! It is obvious that we all are on the "same page".....but the "book" is written by chiefs that have not been in a job since 60 GPM could handle a typical R+C fire.
I have 25 on now. I am just getting to the point of being able to effect change. My advice to everyone here is to not lower your standards, keep up your individual fights, but think like a PAC little chomp at a time. Soon enough, if you do your homework, and your results are indisputable 10 or 20 years from now you will be in position to effect change ( and yes it will be that long). Remember your convictions and do it. When I first got promoted, I had visions of changing everything to what I thought should be done or what was "right". Now my goal is to change just one item for our engines before I retire. Then the next "kid" I influenced will take up the fight...then a kid he influenced will take up his fight, so on and so forth. So after I am long dead and worm food, change will be made. I know it sucks, but as we said before about the fire service, we move at a snail's pace. "centuries of tradition un-impeded by progress". But we also should not effect change just for the sake of change.
Keep the faith
We flow 125 gpm thru TFT fog nozzles. IMO, that is the least that you should flow for any interior job. If you have the manpower, 250 gpm lines are the way to go.
Awesome thread and very good info I can use for my fight at my volly house(whole different story!!) Where i work we flow 150gpm w/the 50 psi chief nozzles...great nozzles, but im a smooth bore fan. I carry a 15/16" in my pocket for many many reasons. Dont always think to use it though.

I have a question for you guys...I have tried this scenario twice. A 7/8" slug on 100' 1 3/4 attack line. On a 1990 seagrave w/ a waterous pump at a pressure of 100psi, i flow a great stream w/ very little nozzle reaction. (no pitot or flow meter)
And on a 1990 KME w/a Hale pump, the same nozzle, same size hose but different make, at 100psi, and it comes close to knocking me off my feet, when i lowered the discharge pressure to 80psi, I got better stream w/longer reach but still very strong nozzle reaction. Anybody have any thoughts on this? Or can you personally describe the NR you receive when utilizing SB nozzles.
Due to the fact of the different designs of the plumbing in the pump area, your rigs will be different. The reason is the bends in the piping on the pump, and that creates turbulance which can increase internal pressures in the systems. If you were to put a inline gauge on each of your discharges, I would bet you will find disparities between the master pump discharge gauge, which is picked up over the top of the impeller, the outlet's discharge gauge, which is picked up past the ball valve, and the inline gauge.
KME are known for their tight pump package areas, with a lot of bends in the plumbing.
Hope that helps
Just a question, why are you guys trying to push 200 GPM through the line? Your nozzle reaction must be tremendous? My agency just completed a boatload of testing for flows, and we found that formula friction losses are way too much. We are now running our 1 3/4" at 15 PSI per length, (we teach by lengths as we have pre connects and static loads). We are now running all our hand held smoothbores at 40 PSI, nozzle pressure, as it cut down nozzle reaction tremedously and actually tightened up the stream. We are putting out 175 GPM with 1.75 in, and 260 gpm with 2 1/2" with a 1 1/8" tip.
If you guys are running 200 gpm with the 15/16" it is a great line, but I bet you need some help moving on interior operations.
Be wary of Sho Flos. They are almost always off by as much as 20 percent.
Do you use CAFS lines for supported interior attacks? Meaning I see the need for them at stations that will perform a transitional (defensive to offensive) knock down from the outside. We are facing implementation of CAFS Engines into our fleet. What are your flows for: 1 3/4, 2 1/2 interior lines? Do you use CAFS for interior attacks in structures that do not have carpet or other absorbant materials for flooring? We are looking for tactical information on the actual use of CAFS for interior attacks. Thanks, Scott
Agreed on the testing. You'll never know what you're really flowing unless you lay it out and see.

However, here's a good rule of thumb for 3:00 a.m.:

I call it "Joe's 12-20-25 Rule" (you can substitute your own name...)

For 2.5" lines with 1.25" tips: Roughly 325 gpm and 12 psi loss per 50' section
For 1.75" lines with 7/8" tips: Roughly 160 gpm and 20 psi loss per 50' section
For 1.75" lines with 15/16" tips: Roughly 180 gpm and 25 psi loss per 50' section.


NOTE: These are 50' sections, not 100' of length, like you'd use in CQsquaredL and such.

Our department carries all three of these tips and it works out pretty well (you've just gotta remember to pull the 1" and 1.125" tips off the deuce's stack first). We also carry TFTs and the same friction loss applies if you use the same target flows, just be sure to add another 50# nozzle pressure.


We use TFT's on 1.75"  w 100 psi settings. We send 200 p.s.i. to them. This should, in theory, give you 200 gpm provided you don't have kinks and the TFT is in proper working order. Realistically because of friction loss, kinks, (ever seen a line with no kinks at all?) but 175 to 180 is probably more like it. Our TFT's are well maintained, but those kinks are, well, kinks. We kick 'em out as best we can. We use a smooth bore and 2" on hi rise jobs.


Policy Page


The login above DOES NOT provide access to Fire Engineering magazine archives. Please go here for our archives.


Our contributors' posts are not vetted by the Fire Engineering technical board, and reflect the views and opinions of the individual authors. Anyone is welcome to participate.

For vetted content, please go to

We are excited to have you participate in our discussions and interactive forums. Before you begin posting, please take a moment to read our community policy page.  

Be Alert for Spam
We actively monitor the community for spam, however some does slip through. Please use common sense and caution when clicking links. If you suspect you've been hit by spam, e-mail

FE Podcasts

Check out the most recent episode and schedule of

© 2024   Created by fireeng.   Powered by

Badges  |  Report an Issue  |  Terms of Service