Friction Loss Flow Charts
Feet Of Head Pressure Loss Per 100 Ft. of Plastic Pipe
Example: Using 1" pipe flowing at 5 GPM you would lose 1.72 feet of head pressure per hundred feet
| GPM |
Pipe Diameter |
| 1/2" |
3/4" |
1" |
1-1/4" |
1-1/2" |
2" |
2-1/2" |
3" |
4" |
5" |
6" |
| 1 |
2.08 |
0.51 |
|
|
|
|
|
|
|
|
|
| 2 |
4.16 |
1.02 |
0.55 |
0.14 |
0.07 |
|
|
|
|
|
|
| 5 |
23.44 |
5.73 |
1.72 |
0.44 |
0.22 |
0.066 |
0.038 |
0.015 |
|
|
|
| 7 |
43.06 |
10.52 |
3.17 |
0.81 |
0.38 |
0.11 |
0.051 |
0.021 |
|
|
|
| 10 |
82.02 |
20.04 |
6.02 |
1.55 |
0.72 |
0.21 |
0.09 |
0.03 |
|
|
|
| 15 |
|
42.46 |
12.77 |
3.28 |
1.53 |
0.45 |
0.19 |
0.07 |
|
|
|
| 20 |
|
72.34 |
21.75 |
5.59 |
2.61 |
0.76 |
0.32 |
0.11 |
0.03 |
|
|
| 25 |
|
|
32.88 |
8.45 |
3.95 |
1.15 |
0.49 |
0.17 |
0.04 |
|
|
| 30 |
|
|
46.08 |
11.85 |
5.53 |
1.62 |
0.68 |
0.23 |
0.06 |
0.02 |
|
| 35 |
|
|
|
15.76 |
7.36 |
2.15 |
0.91 |
0.31 |
0.08 |
0.03 |
|
| 40 |
|
|
|
20.18 |
9.43 |
2.75 |
1.16 |
0.40 |
0.11 |
0.03 |
|
| 45 |
|
|
|
25.10 |
11.73 |
3.43 |
1.44 |
0.50 |
0.13 |
0.04 |
|
| 50 |
|
|
|
30.51 |
14.25 |
4.16 |
1.75 |
0.60 |
0.16 |
0.05 |
0.02 |
| 60 |
|
|
|
|
19.98 |
5.84 |
2.46 |
0.85 |
0.22 |
0.07 |
0.03 |
| 70 |
|
|
|
|
|
7.76 |
3.27 |
1.13 |
0.30 |
0.10 |
0.04 |
| 75 |
|
|
|
|
|
8.82 |
3.71 |
1.28 |
0.34 |
0.11 |
0.05 |
| 80 |
|
|
|
|
|
9.94 |
4.19 |
1.44 |
0.38 |
0.13 |
0.05 |
| 90 |
|
|
|
|
|
12.37 |
5.21 |
1.80 |
0.47 |
0.16 |
0.06 |
| 100 |
|
|
|
|
|
15.03 |
6.33 |
2.18 |
0.58 |
0.19 |
0.08 |
| 125 |
|
|
|
|
|
|
9.58 |
3.31 |
0.88 |
0.29 |
0.10 |
| 150 |
|
|
|
|
|
|
13.41 |
4.63 |
1.22 |
0.40 |
0.20 |
| 175 |
|
|
|
|
|
|
|
6.16 |
1.63 |
0.54 |
0.20 |
| 200 |
|
|
|
|
|
|
|
7.88 |
2.08 |
0.69 |
0.30 |
| 250 |
|
|
|
|
|
|
|
11.93 |
3.15 |
1.05 |
0.40 |
| 300 |
|
|
|
|
|
|
|
|
4.41 |
1.46 |
0.60 |
| 350 |
|
|
|
|
|
|
|
|
5.87 |
1.95 |
0.80 |
| 400 |
|
|
|
|
|
|
|
|
7.52 |
2.49 |
1.00 |
| 450 |
|
|
|
|
|
|
|
|
|
3.09 |
1.30 |
| 500 |
|
|
|
|
|
|
|
|
|
3.90 |
1.50 |
Friction Loss in PVC Fittings = EQUIVALENT FEET OF STRAIGHT PIPE
Using fittings creates friction loss:
Below we show the comparison of friction loss of "average" fittings compared to "average" feet water travels inside pipe.
Example: using one 1/2" 90 degree elbow is approx. the same as using 1 1/2 feet of 1/2" pipe
The less fittings that you are able to use, the less friction loss you'll have!
PVC
Type |
Pipe Size |
| 1/2" |
3/4" |
1" |
1-1/4" |
1-1/2" |
2" |
2-1/2" |
3" |
4" |
6" |
8" |
| 90° elbow |
1.5 |
2.0 |
2.25 |
4.0 |
4.0 |
6.0 |
8.0 |
8.0 |
12.0 |
16.7 |
21.0 |
| 45° elbow |
0.75 |
1.0 |
1.4 |
1.75 |
2.0 |
2.5 |
3.0 |
4.0 |
5.0 |
8.0 |
10.6 |
| insert coupling |
0.5 |
0.75 |
1.0 |
1.25 |
1.5 |
2.0 |
3.0 |
3.0 |
4.0 |
-- |
-- |
| gate valve |
0.3 |
0.4 |
0.6 |
0.8 |
1.0 |
1.5 |
1.6 |
2.0 |
3.0 |
-- |
-- |
| male/female adapter |
1.0 |
1.5 |
2.0 |
2.75 |
3.5 |
4.5 |
5.5 |
6.5 |
9.5 |
-- |
-- |
| tee-flow (run) |
1.0 |
1.4 |
1.7 |
2.3 |
2.7 |
4.3 |
5.1 |
6.3 |
8.3 |
12.3 |
14.0 |
| tee-flow (branch) |
4.0 |
5.0 |
6.0 |
7.0 |
8.0 |
12.0 |
15.0 |
16.0 |
22.0 |
32.7 |
49.0 |
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