RE: Re: Control valve station

Santharam,

I will paint you a picture based on my automotive application experience.

A control valve station normally consist of the Control valve. On each side of the control valve

would be a shut-off valve (to separate the system when control valve need service). On each side

of the shut-off valves is your by-pass connection with a throttling valve. This by-pass line is used for

emergency only when the control valve needs service (normally). Upstream of the first by-pass

connection a strainer is ideal, but I have seen some installation without..

I will only address the by-pass line placement. Don't forget this is only based on my automotive plant

experience. Your application or project standard might be calling for something else.

Normally, since the by-pass line is only used for emergency, we would prefer it to be installed above

the control valve. But depending upon your space limitation, the by-pass line can be installed horizontally

parallel to the control valve. We only place the by-pass line below the control valve as a last resort,

because we don't want any trapped liquid(medium) around the control valve assembly.

Depending upon the height of your control valve assembly, my preference is to place the by-pass line

directly above the control valve. This saves plant floor space, easier to fabricate and easier to ship especially

if you are shipping this as an assembly with floor mounted supports, etc. Now if your control valve actuator

is too high, you can rotate this by-pass line anywhere from the vertical to horizontal position.

I hope this picture helps you.

Ed

From: PipingDesign@yahoogroups.com [mailto:PipingDesign@yahoogroups.com] On Behalf Of santharam_be
Sent: Thursday, February 21, 2008 1:54 AM To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] Re: Control valve station

> > Both the gate valves are present at both
> > the sides of control valve. In some cases the bypass valve is
placed
> > parallely above the control valve & in some other cases it is
placed
> > at 45 degrees vertical to the control valve. why is it so?
> Responses to this question will probably be a lot more helpful if
you
> explain why you need to know. There are a hundred possible
reasons
> why physical arrangements are made. Why is this important to you?

while i was referring condensate area in a project previously i saw that the bypass valve is placed at 45 degree to the control valve & now i am working in ARU unit in refinery project. so i like to know how the bypass valve can be placed.

[Non-text portions of this message have been removed] Received on Thu Feb 21 10:03:00 2008