Equivalent Lengths (Le/D) for Valves and Fittings

[MechanicalMan]

Can anyone recommend any good references for equivalent length data for valves and fittings? All of my fluid mechanics books only have data for fully opened vales, but I'm currently working on a project where I need to know the values for partially closed valves.

I tried to do a Google search but came up with nothing relevant. Thanks in advance.

 

[stewartcs]

Try "Crane Technical Paper 410". My copy is at the office but I seem to remember them having some tables listed in the appendix.

 

[FredGarvin]

For information like that, you'll need to get curves from the manufacturer of the valves. I can't remember any off the top of my head that listed partially open flows. Even Crane makes the distinction of fully open on most valves in its section of resistance coefficients. There is one exception in which they list a tilting disc check valve opening of 5° and 15°.

 

[MechanicalMan]

Thanks for your responses.

I looked into the paper today, but it wasn't exactly what I needed. I may just need to do some tests and try to solve for it empirically.

 

[stewartcs]

I just happened to run across this today...it shows so equivalent lengths for partially closed valves.

http://www.constructionwork.com/resources_details_1474friction_of_fittings.html