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Friction Loss

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Friction Loss Calculator

Friction Loss Formula

Friction Loss Chart
Fire Hose Friction Loss Formula
Friction Loss
occurs when water is pumped through a hose or pipe. Distance, diameter, and the GPM all affect friction loss. As water passes through the fire hose, friction develops between the moving water and the inside surface of the hose. This turbulance reduces the PSI at the other end of the hose. The friction loss formula calculates the friction loss for hoses between 3/4" & 6" diameter.
Use the following formula to determine friction loss. You can use a scientific calculator or if you are good with math, write out the equation by hand to solve for friction loss. Create your own friction loss problems, like the problem below, and solve for the answer. Use the online
Friction Loss Calculator
to verify your answer.
Fire Hose Friction Loss Formula
FL = C * (Q / 100) ^2 * L / 100
FL = Friction loss in PSI
C = Friction loss Coefficient (Table 1)
Q = Flow rate in GPM
L = Hose length
Example:
Determine the friction loss for a 100 foot section of 1 inch hose with 60 GPM of flow.
FL = C * (Q / 100) ^2 * L / 100
54.0 = 150 * (60 / 100) ^2 * 100 / 100
Coefficient (
C
) for 1" hose is 150
GPM (
Q
) = 60 GPM
Length (
L
) = 100 feet
Answer:
There is 54.0 PSI of friction loss for a 100 foot section of 1 inch hose with 60 GPM of water passing through it.
Table 1
Friction Loss Coefficient
Diameter
Coefficient
0.75 inch hose
1100
1 inch hose
150
1 ¼ inch hose
80
1 ½ inch hose
24
1 ¾ inch hose
15.5
2 inch hose
8
2 ½ inch hose
2
3 inch hose
0.677
3 ½ inch hose
0.34
4 inch hose
0.2
4 ½ inch hose
0.1
5 inch hose
0.08
6 inch hose
0.05
Methods to determining friction loss calculations:
The
Friction Loss Formula
calculates friction loss for fire hose between 3/4" & 6" and is the most accurate method. But, determining friction loss with this method is the most time intensive, has a high probablity for human error, and is not very practical in the field or for learning hydraulics theory.
The
Friction Loss Calculator
will calculate Friction loss for any size fire hose between 3/4" & 6". This method uses the friction loss formula to perform calculations and is just as accurate.
The
Friction Loss Slide Rule
can provide calculations for a wide variety of hose sizes and is faster than the friction loss formula, but it has a higher probability for human error, and the slide rule is the least accurate of the three methods.
The
Friction Loss Chart
(by
FireDepartment.net
)
provides a friction loss chart for each size of hose between 3/4" & 6". The Friction Loss Grid is a little more bulky, but is the easiest, fastest, and a very accurate method of determining friction loss.
Information about
Hardware Friction Loss
.
FireDepartment.net strives to provide fire departments & firefighters with qulaity tools. But, the user takes full responsiblity for the information contained above. Use at your own risk!
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