Roughness values

[element94]

I'm looking for a table on roughness values for various materials. Specifically plastic. Thank you.

 

[Latexman]

Most plastics I've dealt with have been modelled as "smooth" with good success.

Good luck,
Latexman

 

[briand2]

For typical pipe materials (PVC, etc), use absolute roughness ("ks") = 0.003 mm (as compared to about 0.0015 mm for copper, 0.046 mm for new black steel pipe).

Regards,

Brian

 

[element94]

Thanks. I was using 0.00005 ft (.0015 mm).

 

[25362]

I found some values by a Google search in:

http://www.fluidedesign.com/download-free/pipe_rough_values.pdf

 

[briand2]

My figures are from the CIBSE guide (as used for pipe sizing for building services in the UK; equivalent to ASHRAE).

Regards,

Brian

 

[WebWizz]

Another good link:

http://engineeringpage.com/technology/pressure_drop/wall_roughness.html

Also pressure drop calculations etc.

Best Regards - Wim