What is your Target Flow?

Replies to This Discussion

Permalink Reply by Tony Piontek on March 18, 2008 at 4:47pm

High flow all the way...the knockdown and reach are what you need. Remember it's physics, more gpms than btus. Don't have to tell you that but you might want to remind the others. We use 2 types of nozzles, SM-30's (automatic) and chiefs (constant Gal, 200@75psi), and when I do live fire training, its a smoothbore 15/16 or 1" tip on a 1 1/2 shutoff. I don't particularly mind the higher pressure of the SM-30, sometimes it helps having that line under extreme pressure for less kinks and for up/down stairs. Gallons brother, gallons! Oh and by the way...180gpm+ is my goal for 1 3/4, cant get it from a 1 1/2.

Permalink Reply by Ray on March 19, 2008 at 11:10pm

I use a simple formula
1 3/4 line 175 GPM
2 1/2 line 250 GPM

Permalink Reply by Bob Shovald on March 20, 2008 at 4:52pm

Shane -
We use a break-apart nozzle. The combination tip is 150gpm @ 50 psi attached to a 15/16" slug tip (Akron Assult) We flow 185 gpm from the soild stream and average 165 gpm with the combination tip in place. We marked the discharge gauges at the 185 gpm flow setting using the solid stream. With the combination tip in place and flowing at the predetermined mark on the discharge gauge we see a flow of 165 gpm using the combination tip. This allows the engineer to flow either the soild or the combination tip at the same nozzle pressure of 50 psi. We use 1 3/4" lines on our apparatus. For our 2 1/2" lines we use only 1 1/4" solid stream tips for around 325 gpm. As for your initial question we determined our target flow to be no less than 150 gpm for interior operations. The problem with automatic nozzles is without a flow meter the engineer does not know what gpm he/she is suppling the attack crew. Keep pushing for the change its all about safety.

Permalink Reply by Shane Furuta on March 20, 2008 at 7:27pm

Thanks Brothers! This all great stuff... Exactly what I am looking for, keep it coming!

Permalink Reply by Ray on March 20, 2008 at 8:53pm

Shane - What you are flowing (100 GPM's) is way below what you should be flowing. When I say 175 for 1 3/4 you can go higher and you can go a bit lower.
You need to set up a side by side comparison test with the powers that be and show everyone what the differences are between the two flows. Fire department handlines should not remind us of garden hoses. P.S. Tell your chiefs to pick up a fire magazine once and awhile, it is 2008.

Permalink Reply by Shane Furuta on March 20, 2008 at 9:19pm

Ray- I totally understand this... I don't plan on giving up on this one. Mean while, I will continue to educate the ones who want to listen, and keep working on the ones who don't. I will be in Indy this year, I'll be sure to find you and say hi. Thanks again for the comments...

Permalink Reply by Kristofer DeMauro on March 20, 2008 at 10:16pm

Shane,

You have hit an age old situation right on the nose. Many firefighters believe that you must use water sparingly on a fire to limit the damage caused by water. Just because a line can flow 200 gpm does not mean that you are going to apply that much. On my rig we use TFT 75 psi nozzles that flow up to 200 gpm (as claimed in the technical data). I use the NFA formula for calculating needed fire flow. (length X width divided by 3 for a 100% involvement). For a typical 1800 sf home or floor that would be 600 gpm for a fully involved, 300 gpm for 50%, 150 for 25%, and so on. This give a ballpark number only, adjustments need to be made for contents and exposures. I have included a copy of an article that was published on the Fire Engineering web page titles "The Thompson Diagram." It contains a chart that I use. I hope it helps. Keep pushing and remember no only means no today, not tomorrow!

Attachments:

• thompson diagram.rtf, 6.4 MB

Permalink Reply by Jay Michael on March 21, 2008 at 1:53pm

Lots of water, If it is burned its junk, if it gets wet it will dry. Use lots of water, knock the crap out of the fire, then shut the water off. Our 1.75" hose has 15/16 tip getting 180 gpm maybe a little more. Our 2.5" hose has 1.250" tip getting a little over 320 gpm. Pump operators are trained to pump these lines properly. Company officers may request a little more or less depending on conditions.

We used to use automatic SM20 and SM30 Elkhart Brass nozzles. In the mid 90's we flow tested these and found we were only getting 65-85 gpm out of the SM20. Crews said they were too hard to handle at proper nozzle pressure. Given they were automatics, the fire stream looked good, just didn't have any water in it. Didn't take long for the purse strings to loosen and we got our current nozzles.

I am not trying to make a debate on nozzle types, the absolute best nozzle to use to attack a fire is.... the one in your hand. Use it to its fullest advantage.
Jay

Permalink Reply by Greg Wyant on April 4, 2008 at 6:31pm

Have you thought about going to the 2" attack line?? 210GPM @50PSI with a 1" tip it has the knock down power of a small cannon. Go up to 60PSI 225GPM. My department has had a lot of sucess with the 2" line.

Permalink Reply by Sean Stumbaugh on April 7, 2008 at 1:26pm

Hey Ya'll,

This has been a debate in my department forever. It has been a goal of mine to try to set a target flow for a long time. I have been in the training division now for three years and I am about to see success. Our problem has been one of explosive growth. Our community grew so fast that we had an influx of people in the deapartment and have had people doing duplicate efforts in ordering equipment. That has led to a wide variety of nozzles. A few years ago we started buying CAFS on our engines. We are 100% CAFS now. This means we carry a combination nozzle with a breakaway to a 7/8" slug tip.
Every where I go I ask what people are using for target flows. I get a wide variety of answers. It seems that no one wants to go out on a limb to publish their findings. The only place I have seen it written down has been in Fire Engineering articles. I have used those articles and NFPA 1410 to come to my conclusion. I have also used the input from my line captains (they're the ones who do the work!). The problem I run in to is what their desired target flow is. The range of opinions is as wide as the number of captains out there. Someone had to make a decision to put this debate to bed.
Long story short (good luck)? 1410 says the first line off should be 100 GPM, the second line off (backup) should be 200 GPM. We can pump 100 GPM at idle, and some of my captains wont accept a 200 GPM 1 3/4" line. My compromise? Split the difference. Since the net flow in 1410 is 300 GPM for initial operations I set our minimum flow at 150 GPM. We tested each apparatus with 4 different types of nozzles. We also tested 180 GPM and 200 GPM. We got the high and low PSI reading and also published an average across the district. We then put the information out to a vote. We settled on an Akron fog tip with 7/8" slug and a pistol grip ball shut off. With all of this information we convinced our operations division to purchase the required number of nozzles to standardize everything in the department. We now have a minimum flow of 150, a target flow of 180, and a maximum flow of 200 GPM on an 1 3/4" hand line. If you need more than that its time to drop the 2 1/2" (thats another debate!).
With our 7/8" tip we can get 160 GPM, thats above our minimum. That's also the size tip we carry into buildings with stand pipes. This standard gives captains who like softer lines the ability to get what they want and max flow captains to have their engineers pump it a little hotter.
With this standard we were able to get a department specific friction loss coeficient for 1 3/4" hose, standard engine pressure charts, and a standard pressure relief valve setting. This is all brand new so I am waiting for feedback from the line, we'll see how it goes.
If you want further information let me know!

Sean

Permalink Reply by Sean Stumbaugh on April 7, 2008 at 1:37pm

One more item to think about, BTUs per pound of fireloading have doubled with the introduction of plastics into our homes. If you are using 100 GPM as your target flow thats too "old school". Your fire loads are more like 16,000 BTUs per pound as compared to 8,000 BTUs per pound. I'm no scientist but it seems smart to me that twice the BTUs equals twice the water. I got as close to that as I could get with a target of 180 GPM.

Keep fightin' the fight Brother!

Sean

Permalink Reply by Bob Shovald on April 8, 2008 at 10:36am

Sean -
Your reply was very interesting. I was involved in a simular situation. Ours ended up almost exactly as yours did with one exception. Instead of a 7/8" slug tip we choose the 15/16". We also flowed the preconnects using a flow meter with the slug tip in place. When the slug tip was flowing 185 gpm we marked the discharge gauge with a reflective arrow. We found that when the engineer uses ths predetermined mark with the 150/50 fog nozzle in place the line actually flows 165gpm. This system has worked very well for us.
Bob

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