UMG70XV3-4EN 12.01.2009 231
C Reference
Table C.2: Typical Roughness Coefficients of Pipes
The values are based on experience and measurements.
material absolute roughness
[mm]
drawn pipes of non-ferrous metal,
glass, plastics and light metal
0…0.0015
drawn steel pipes 0.01…0.05
fine-planed, polished surface max. 0.01
planed surface 0.01…0.04
rough-planed surface 0.05…0.1
welded steel pipes, new 0.05…0.1
after long use, cleaned 0.15…0.2
moderately rusted, slightly encrusted max. 0.4
heavily encrusted max. 3
cast iron pipes:
bitumen lining > 0.12
new, without lining 0.25…1
rusted 1…1.5
encrusted 1.5…3