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| Absolute Pipe Roughness |
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Included here is a sampling of absolute pipe roughness e data taken from
Binder (1973). These values are for new pipes;
aged pipes typically exhibit in rise in apparent roughness. In some cases this rise can be very significant.
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| Pipe Material |
Absolute Roughness, e |
| x 10-6 feet |
micron
(unless noted) |
| drawn brass | 5 | 1.5 |
| drawn copper | 5 | 1.5 |
| commercial steel | 150 | 45 |
| wrought iron | 150 | 45 |
| asphalted cast iron | 400 | 120 |
| galvanized iron | 500 | 150 |
| cast iron | 850 | 260 |
| wood stave | 600 to 3000 | 0.2 to 0.9 mm |
| concrete | 1000 to 10,000 | 0.3 to 3 mm |
| riveted steel | 3000 to 30,000 | 0.9 to 9 mm |
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Relative pipe roughness is computed by dividing the absolute roughness e by the pipe diameter D,
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