Loss of head in feet per 100 feet of pipe length
This chart shows friction losses in various pipe materials at the standard water temperature of 68.4 F or 20.2 C. This chart is just a guide. There are too many types of pipe to list individually. The PVC column shows a slightly better pipe choice than average. The polyethylene is a slightly worse choice. The cast iron reference is almost a worst case scenario but sometimes a necessary pipe choice for very high head pipelines. You should also check the flow velocity chart and temperature chart for reference and keep the number of sharp turns to a minimum.
| GPM | 3/4″ PVC Class 160 |
3/4″ PE SDR |
3/4″ Cast Steel |
1″ PVC Class 160 |
1″ PE SDR |
1″ Cast Steel |
1.25″ PVC Class 160 |
1.25″ PE SDR |
1.25″ Cast Steel |
1.5″ PVC Class 160 |
1.5″ PE SDR |
1.5″ Cast Steel |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.17 | 0.28 | 0.5 | 0.05 | 0.09 | 0.2 | 0.02 | 0.02 | 0.05 | |||
| 2 | 0.62 | 1.04 | 2.0 | 0.14 | 0.32 | 0.6 | 0.05 | 0.09 | 0.16 | 0.02 | 0.04 | 0.06 |
| 3 | 1.3 | 2.19 | 4.0 | 0.32 | 0.67 | 1.1 | 0.09 | 0.19 | 0.29 | 0.04 | 0.09 | |
| 4 | 2.3 | 3.73 | 7.2 | 0.53 | 1.15 | 1.8 | 0.16 | 0.30 | 0.50 | 0.09 | 0.14 | 0.27 |
| 5 | 3.6 | 5.61 | 11.0 | 0.8 | 1.75 | 2.6 | 0.25 | 0.46 | 0.78 | 0.12 | 0.21 | 0.34 |
| 6 | 4.7 | 7.89 | 15.0 | 1.13 | 2.44 | 3.6 | 0.35 | 0.65 | 1.1 | 0.18 | 0.3 | 0.51 |
| 7 | 6.3 | 10.5 | 20.4 | 1.52 | 3.24 | 4.8 | 0.46 | 0.85 | 1.44 | |||
| 8 | 7.8 | 13.4 | 25.5 | 1.9 | 4.1 | 6.2 | 0.58 | 1.08 | 1.82 | 0.3 | 0.51 | 0.84 |
| 10 | 12.1 | 20.3 | 39.0 | 2.9 | 6.3 | 9.4 | 0.87 | 1.66 | 2.7 | 0.46 | 0.78 | 1.1 |
| 12 | 4.1 | 8.8 | 13.0 | 1.22 | 2.32 | 3.76 | 0.64 | 1.11 | 1.6 | |||
| 14 | 5.45 | 11.7 | 17.1 | 1.63 | 3.1 | 5.0 | 0.85 | 1.45 | 2.2 | |||
| 16 | 7.0 | 15.0 | 21.8 | 2.1 | 3.9 | 6.5 | 1.08 | 1.87 | 2.8 | |||
| 18 | 8.7 | 18.6 | 27.1 | 2.6 | 4.9 | 8.0 | 1.33 | 2.32 | 3.5 | |||
| 20 | 10.6 | 22.6 | 33.0 | 3.2 | 6.0 | 10.4 | 1.63 | 2.81 | 4.3 | |||
| 25 | 4.7 | 9.0 | 15.2 | 2.48 | 4.27 | 7.0 | ||||||
| 30 | 6.7 | 12.6 | 21.2 | 3.5 | 5.96 | 9.5 | ||||||
| 35 | 8.9 | 16.8 | 27.3 | 4.6 | 7.94 | 12.5 | ||||||
| 40 | 11.4 | 21.5 | 35.2 | 5.9 | 10.2 | 16.0 | ||||||
| 45 | 7.3 | 12.7 | 19.6 | |||||||||
| 50 | 8.9 | 15.4 | 24.0 | |||||||||
| 55 | 10.6 | 18.3 | 28.6 | |||||||||
| 60 | 12.5 | 21.5 | 34.0 | |||||||||
| 65 | 14.4 | 23.8 | 39.2 | |||||||||
| 70 | 16.6 | 28.7 | 45.0 | |||||||||
| 75 | 18.8 | 32.7 | ||||||||||
| 80 | 21.3 |