Hand Method for Calculating Friction Loss for Firefighters

[Yourname-hxwy]

Currently going through pump ops now! I been driving and pumping for 8 years, now they want us to have the class 😑 I’m halfway through and these videos have helped me understand a little better. A good resource to recap the days teaching! Thank you from Florida!

[richardkeilig]

Excellent class! I watch your videos often so I do not forget the main objectives and learning points.

[cbartoniv]

Explained very well! Thanks for posting! I watched/listened to all 7.

[FireForLunch]

So do you have a link for the video for the Subtract 10 method for 2.5?

[cm]

I think the 12 multiplier is too much on the 1 3/4.

[Kotten-Mason]

Will this work on a po practical.... also any difference in 2 inch hose

[jackbombajr]

Hello, I'm a firefighter in Brazil, in the city of São Paulo, I found this hand rule interesting, as it would be in our reality, do we use a one 30 meters 2.5 'hose, a derivative and a one 30 meters 1.5' hose more spray gun type?

[nelsongomez]

When you explain using the 246810 you were x the ist digit x the number in you hands. Here you did not use the coefficient.
Confused, or maybe I am just stupid♑️♎️♐️🈚️

[nick]

is there a hand method for 3 inch hose

[nelsongomez]

So you x 100x1 but when you use the 150 you x the # on 150 x the c(12) 36. Why you didn’t x 150x3x12. Confusing to me.

[broscup]

Are these the current IFSTA methods?  I know the older edition for 1 3/4" showed 9 for 125gpm and above and 12 for 100gpm.  Looking around the nets I'm finding multiple versions.

[davidhopkins]

when I learned the hand method the multiplier for the 2.5" Hose began with 3 as the thumb number?

[dlewis]

where's the other method you were talking about something 10 method

[stevehutchinson]

What is the multiplier if you are running 1.5" hose? thanks.

[Aekardlehs]

It seems like that multiplier is a bit off. Generally speaking, at 125 GPM you can add 12 PSI per 50 ft of 1.75" to get your friction loss. And if my math is correct, you should get roughly 18 PSI of friction loss per 50 ft or 1.75" section at 150 GPM. It's just a quick and easy method to get roughly the correct pressure per section per GPM. I know it isn't super precise but I feel like the hand method you were using would put you way over your desired pressure. Or maybe I am overlooking something. Does anyone else agree or am I pumping incorrectly?

[TheMajestikmse]

I'm sorry, but even this is just too complicated for use on the fireground. As stated in the beginning, it doesn't account for elevation, or other factors. So what's the point? I know I want 140 psi on the panel when I pull 200' of 1 3/4" with a 100 gpm fog nozzle (standard crosslay on my engines). If I need more or less pressure I ask for it. Sit down, in quarters, and figure this out without clever shortcuts for typical configurations, and make an easy to read chart. That is your starting point, then listen to the guy on the nozzle.