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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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