0.75 Inch Hose - Friction Loss Table
This chart is designed (using the friction loss formula) to find quick and accurate answers for 3/4" fire hose friciton loss. To find the friction loss for a 100 foot section of fire hose, find the column with the desired GPM and to its right you'll see the corrosponding friction loss. You can also print this image on a 8.5x11 sheet of paper.
Example: Friction loss for 100 ft of 3/4" fire hose with 25 GPM is 68.8. You can find the corrosponding friction loss for 25 gpm at the bottom of column 2 in the chart below. You can see that 25 gpm has 68.6 psi friction loss. You can also see the answer on the friction loss calculator
As you can see, 3/4" fire hose has very limited capacity and builds friction loss at a very low GPM. Be careful where you use 3/4 inch fire hose.
Friction Loss Explained
Friction loss occurs when water passes through a hose. Hose length, diameter, and GPM (volume) all affect friction loss. As water passes through a hose, friction between the water and the inside surface of the hose causes turbulence, which slows the water. The results in a PSI drop (pressure loss) at the other end of the hose. The higher the gpm passing through a hose, the more turbulance and friction loss will result.
Friction loss examples:100 ft 1" @ 100 gpm = 150 PSI
100 ft 1 1/2" @ 100 gpm = 24 PSI
100 ft 1 3/4" @ 150 gpm = 34.88 PSI
200 ft 1 3/4" @ 150 gpm = 69.75 PSI
100 ft 1 3/4" @ 185 gpm = 53.05 PSI
200 ft 1 3/4" @ 185 gpm = 106.1 PSI
100 ft 1 3/4" @ 200 gpm = 62 PSI
200 ft 1 3/4" @ 200 gpm = 124 PSI
100 ft 2 1/2" @ 150 gpm = 4.5 PSI
100 ft 2 1/2" @ 200 gpm = 8 PSI
100 ft 2 1/2" @ 300 gpm = 18 PSI
200 ft 2 1/2" @ 300 gpm = 36 PSI
Fire Engine Operator Tools
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