It doesnt matter how long the pipe is; if the Reynolds number says the flow is turbulent, then it will remain so. The main point of the upstream and downstream "D"s is to remove spin from the fluid and to promote an axisymmetric flow profile.
Cheers
Steve McKenzie
-----Original Message-----
From: Paul Bowers [mailto:pbowers@pipingdesign.com]
Sent: Friday, June 13, 2003 3:23 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] Regarding flow element installation in
piping
The ideal flow profile is laminar, so the less turbulent, the better (as mentioned below - I'm just adding a nifty keyword).
http://hyperphysics.phy-astr.gsu.edu/hbase/pfric.html
Paul
> Upstream and downstream straight length requirement depends on
> the fluid, flow conditions and the type of meter used.
> It is merely to straighten / streamline the flow (from turbulence)
> for accurate measurement. Process / Instrument guys can help
> you in deriving this stuff. If you have problems in acheiving this
> straight length in the layout, you can go for flow straightners,
> which are simply a bundle of tubes inserted in the line pipe !
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Received on Fri Jun 13 05:27:00 2003
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