Hello,
Crane TP 410 provides methods to determine the K values for various standard fittings. A turbulent friction factor (fT) is used for doing so and the figures are tabulated for various pipe diameters in the appendix A26. The figures have been determined based on new steel.
Can these figures be applied for materials other than steel piping please?
The system I am looking at consists of polypropylene (PP) piping. If I calculate fT for PP piping (using method described here: http://www.pumpfunda...com/help16.html
Taking into account the absolute roughness for PP piping, the friction factor is reduced to approximately half vs steel piping. The overall effect on the end calculation result (for my system) is a difference in flow capacity of ~5%, this would obviously be greater if the proportion to fittings vs straight pipe was greater.
I have also checked my hand-calculation using AFT Fathom software and checked the help files within the software package to determine the methodology behind the calculations. The software appears to apply the Crane values for fT for all piping material types.
How do other engineers consider this when using pipe materials other than steel please?
Kind Regards,
Ian
Edited by ianmcq28, 05 February 2014 - 05:50 AM.