Re: installation of control valve & instument

From: <elie>
Date: Sun Aug 12 2007 - 17:15:00 EDT

Your question should have included the following:

1. Is the process fluid liquid or gas?
2. In the controller a flow, pressure reducing, or back pressure control valve?
3. What are the Pressure, temperature, and flow rate ranges?
4. Is the flow upstream of the CV laminar or turbulent?

   In my opinion, there are no requirements to the required straight length of pipes for upstream or downstream of the CV unless the flow is turbulent; however, for a pressure control valve, the pressure sensing tap should be located where the system pressure is stable. For flow sensing device, the meter's upstream and downstream required straight length of pipe should be as recommended by the meter manufacturer which varies with the type of meter (orifice, ultrasonic, turbine, vane, diaphragm, etc.

Cheers.
chm_mech <chm_mech@yahoo.com> wrote:

           Hi,
I would like to know what is the thumb rule to decide min straight length of the pipe for installing a control valve & instrument

Thanks for enough in advance

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Pinpoint customers who are looking for what you sell.

[Non-text portions of this message have been removed] Received on Sun Aug 12 17:15:00 2007