- D: Pipe diameter (m)
- ε: Roughness height (m) (More detail show as table below).
Darcy friction factor calculator
Roughness height table:
Surface
|
Absolute Roughness
height ε
|
(x10-3 m) or (mm)
|
|
| Copper, Lead, Brass, Aluminum (new) |
0.001 - 0.002
|
| PVC and Plastic Pipes |
0.0015 - 0.007
|
| Stainless steel, bead blasted |
0.001 - 0.006
|
| Stainless steel, turned |
0.0004 - 0.006
|
| Stainless steel, electropolished |
0.0001 - 0.0008
|
| Steel commercial pipe |
0.045 - 0.09
|
| Stretched steel |
0.015
|
| Weld steel |
0.045
|
| Galvanized steel |
0.15
|
| Rusted steel (corrosion) |
0.15 - 4
|
| New cast iron |
0.25 - 0.8
|
| Worn cast iron |
0.8 - 1.5
|
| Rusty cast iron |
1.5 - 2.5
|
| Sheet or asphalted cast iron |
0.01 - 0.015
|
| Smoothed cement |
0.3
|
| Ordinary concrete |
0.3 - 1
|
| Coarse concrete |
0.3 - 5
|
| Well planed wood |
0.18 - 0.9
|
| Ordinary wood |
5
|