Values of Cp/Cv to calculate pressure drop 2

[presso]

I'm using equations 3.20 in Crane to calculate the pressure drop of a compressible fluid at a give rate through pipes and fittings using values of the net expansion factor fiven in page A-22. However, most of my calculations involves propylene which has a somewhat lower Cp/Cv than the lowest value of page A-22, that is Cp/Cv = 1.3.
Is there a way to obtain similar data for other Cp/Cv values? If not do you think the diffenrence could be important?
Thank you!

 

[TD2K]

thread798-51260

The referenced article in Chemical Engineering magazine addresses the effect the actual Cp/Cv has.

 

[presso]

Thank you TD2K! However, since i don't have an easy access to this magazine, my library is quite far, can you please tell me if the author explains how the lines from Crane's A-22 are obtained? I have already obtained equations by fitting the data under the format Y = m dP/P +1, with m a function of 1/(K+1) but i can't figure how to extend those equations let's say ideally for all k's, ie. Cp/Cv...
Thanks again!

 

[TD2K]

Drop me a line at testdog2000@yahoo.com and I'll forward you a copy of the SS. It has the correlations in it.

 

[presso]

I just did...
Thanks again!!!