Root Valve

Try to answer yourself to the question: why do I want to have a root valve"? the answer will be what you want to find.

This was one response:

PennPiper Power-User Join Date: Feb 2007 Location: Bayonet Point, Florida Posts: 380 Good Answers: 31	# 2 Re: Root Valve 06/22/2008 1:15 PM
	"Root Valve" is a common term used in an oil refinery or other type of process plant as a generalization for a valve that, by its placement is the primary shut-off valve for a sub-header leaving a main header. The "Root" has more to do with the placement or location rather than the type of valve. In a Cooling Water system the Root valve might be a Gate valve or a Butterfly valve. In a Steam system the Root valve would normally be a Gate valve. I have never seen a Globe valve used as a Root valve. __________________ Do it once and do it right
	Score 1 for Good Answer

The valves in question are gate valves. The purpose of them is for our operators to take readings. Now the one option is to leave them always open, as to have constant readings, or to have them closed, and when a reading is required our operators would have to open the valves and take readings (But they are less likely to do this as often as required if this is necessary)

The question should have been stated as, is there a standard that says it's recommended to leave them open, or closed.

Thanks.

Is the pressure almost constant or does it have high amplitude variations ? At which frequency?

The valve can have 2 goals to fulfil:

- protect the valve against fatigue

- allow a valve replacement if failure has been noticed or recalibrating is needed.

Some valves are also used as dynamic low pass in combination with the volume between the valve and the sensitive element of the gage in a part open position.

If no risk of fatigue you can let the valve open if not better closed to avoid to many maintenance operations.