Control valve straight run requirement

[ivarfar]

I'm currently working in a gas compressor module project. As always there is an anti-surge loop with an anti-surge control valve in our module.
Some collegues of mine insist that there should be straight pipe runs (e.g. 6D/4D) on either side of the control valve. It is referred to as good engineering practice. Nobody has come up with a reference to specs, standards, guidelines or the like. I have searched the literature on contol valves that I've come across. No mention of straight runs. Until the oppsite is proven I consider the requirement as a rumor.

Has anybody any reference to a reliable source on this topic?

ivar.farmen@aibel.com

 

[DRWeig]

I've never seen an actual "don't do it" recommendation, but you must take piping geometry into account in calculating valve characteristics to prevent possible cavitation.

There's a good discussion of this in the Emerson/Fisher Control Valve Handbook. I couldn't quickly find a copy to post for you, but I'm betting it's available online from Emerson...

Good on ya,

Goober Dave

 

[JLSeagull]

Try the advanced search. There was another recent post about like this. No straight run required by me.