Root Valve

[Ali Huseyn]

Hi, I would like to ask about "Root" valve does anyone know about this term who engaging in this side?

 

[xnuke]

In instrumentation, a root valve is a valve that isolates pressure, a.k.a. impulse, tubing where it taps off of the process piping before the tubing goes to an instrument. The root valve is typically specified by the process or piping engineers, and its output forms the boundary between the areas of responsibility of the process/piping and instrumentation engineers.

It may mean other things to other people.

xnuke
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[Ali Huseyn]

May we call it output valve?

 

[LittleInch]

No, because it's not outputting anything.

"Primary isolation valve" or just "isolation valve" will do, but root valve is easier to say.

In theory you don't really need one as instruments often install a double block valve in a single block immediately after the piping valve.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[RVAmeche]

See the other threads on this site about root valves; it's a term I've heard in the power plant/chemical industry but apparently it's not a ubiquitous term.

 

[pennpiper]

Ali Huseyn,
The term "Root Valve" relates to a specific "Function" not a Valve Type.

Any shut-off type valve (Gate, Globe, Ball, Plug, Pinch, etc) can function as a "Root Valve" as long as it is in compliance with the specific line class specification.

Check Valves cannot function as a "Root Valve".

As RVAmeche suggested, go here:

https://www.eng-tips.com/viewthread.cfm?qid=446116

Sometimes its possible to do all the right things and still get bad results

 

[Ehzin]

As mentioned, root valve has very little technical meaning. A "Root" valve is the first valve off a process line that provides the first isolation. It provides the branch connections to hook up other instrument/etc... It simply is the first valve to provide isolation from a live system, typically for instrumentation purposes.

Thanks,
Ehzin