Pipe Head Loss Calculator (Darcy-Weisbach Equation)
Calculate Friction Head Loss in Pipes
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Properties of Water (Metric)
| Temperature (°C) | Density (kg/m3) | Viscosity (μPa-s) |
|---|---|---|
| 0 | 999.84 | 1793 |
| 10 | 999.70 | 1307 |
| 20 | 998.21 | 1002 |
| 30 | 995.65 | 797.7 |
| 40 | 992.22 | 653.2 |
| 50 | 988.03 | 547.0 |
| 60 | 983.20 | 466.5 |
| 70 | 977.78 | 404.0 |
| 80 | 971.82 | 354.4 |
| 90 | 965.35 | 314.5 |
| 100 | 958.40 | 281.8 |
Source:
Specific Roughness Coefficient
| Pipe Material | Feet | Meters |
|---|---|---|
| Plastic (PVC, CPVC, HDPE, etc.) | 0.000005 | 0.0000015 |
| Copper and Brass | 0.000005 | 0.0000015 |
| Steel | 0.0002 | 0.00006 |
| Plain Cast Iron | 0.0008 | 0.00024 |
| Concrete | 0.004 | 0.0012 |
Source:
Properties of Water (Customary U.S. Units)
| Temperature (°F) | Density (lb/ft3) | Viscosity (lb-sec/ft) |
|---|---|---|
| 32 | 62.42 | 0.00003746 |
| 40 | 62.43 | 0.00003229 |
| 50 | 62.41 | 0.00002735 |
| 60 | 62.37 | 0.00002359 |
| 70 | 62.30 | 0.00002050 |
| 80 | 62.22 | 0.00001799 |
| 90 | 62.11 | 0.00001595 |
| 100 | 62.00 | 0.00001424 |
| 110 | 61.86 | 0.00001284 |
| 120 | 61.71 | 0.00001168 |
| 130 | 61.55 | 0.00001069 |
| 140 | 61.38 | 0.00000981 |
| 150 | 61.20 | 0.00000905 |
| 160 | 61.00 | 0.00000838 |
| 170 | 60.80 | 0.00000780 |
| 180 | 60.58 | 0.00000726 |
| 190 | 60.36 | 0.00000678 |
| 200 | 60.12 | 0.00000637 |
| 212 | 59.83 | 0.00000593 |
Source:
Darcy-Weisbach Equation:
$$h_{f} = {{f L v^{2}} \over {2Dg}}$$ where:
- H = Head Loss
- L = Length
- c = Velocity
- f = Darcy Friction Factor
- g = Gravity
