Friction factors for PE Pipe Bends? 1

[Andy J]

How do you figure friction losses in PE pipe bends? I have a found a few references to fittings with friction coefficients for actual fittings such as a 90 degree bend with a fitting, but can't find anything about friction in bends. We are planning to curve the actual pipe and not use fittings. A couple of the curves will be 90 degrees with the min. radius of about 8 feet for a 4" pipe.

Would could use an equivalent pipe length for say a 90 degree bend, but this seems like it would be overkill.

 

[BigInch]

NIST recommends the method investigated in this paper,

http://nvlpubs.nist.gov/nistpubs/jres/18/jresv18n1p89_A1b.pdf

 

[bimr]

Unless you have an extensive quantity of curves, one can disregard the friction loss and use the friction factors for straight pipe. The headloss method that you are using is only accurate to 10% at best.