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07-04-2019, 10:02 PM #1
Danfoss stop valves flow direction
Danfoss Industrial ammonia stop valves.
Any preference for direction?
Reasoning for that.
Thanks
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08-04-2019, 01:40 PM #2
Re: Danfoss stop valves flow direction
Do you have a valve model/type as there are different preferences for different models.
Brian - Newton Abbot, Devon, UK
Retired March 2015
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Re: Danfoss stop valves flow direction
To achieve optimum flow conditions, the valve should be installed with the flow towards the valve cone as indicated by the arrow on the side of the valve body. Flow in the opposite direction is also acceptable, but slightly reduces the kv- / Cv value.
-Cheers-
Tycho
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08-04-2019, 05:40 PM #4
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Re: Danfoss stop valves flow direction
Hi
direction of valves
zzzz.jpg
all valves should install in right direction.
seat of valve( Teflon ) has more pressure and get damage in long timeLast edited by mbc; 08-04-2019 at 05:51 PM.
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08-04-2019, 09:11 PM #5
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08-04-2019, 09:18 PM #6
Re: Danfoss stop valves flow direction
Last edited by RANGER1; 10-04-2019 at 08:35 PM.
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08-04-2019, 09:22 PM #7
Re: Danfoss stop valves flow direction
Tycho,
With ICF valve stations Danfoss don't seem to worry about valve direction!
I understand with single stop valves as you have stated.
http://files.danfoss.com/technicalin....A7.02_ICF.pdf
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16-04-2019, 05:33 AM #8
Re: Danfoss stop valves flow direction
Hi,
Everyone agrees that the stop valves should always close against the flow(flow to open configuration.
This type of flow direction lets the disc to rotate freely on the valve stem. This allows the disc to fit properly against the seat as the valve closes, which results in less seat leakage
It won't expose the PTFE glands or packing directly to high-velocity flow.
It won't cause impurities to trap on top of the disc thus plugging the stem movement.
But check the image from Danfoss. Its a hot gas defrost line and they put stop valves in both directions.
valve.JPG
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16-04-2019, 08:47 AM #9
Re: Danfoss stop valves flow direction
Not everyone uses valves this big, but more common.
See page 6
could be a trap when working on system if pressures build up.
The DL is mostly used as is a lot cheaper.
http://files.danfoss.com/TechnicalIn...1/rd7as122.pdfLast edited by RANGER1; 16-04-2019 at 08:50 AM.
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Re: Danfoss stop valves flow direction
We mostly use larger valves like this on liquid separators, and on those I always have the valves positiones so the that if the pressure rises in the tank it will push the seat towards closed.
I worked with a technician 20 years ago that was insisting that it should be the other way around so that you wouldn't rip the teflon seat off when opening the valves.
in 22 years I've never had that happen with a main valve.-Cheers-
Tycho
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16-04-2019, 08:57 PM #11
Re: Danfoss stop valves flow direction
Tycho, thanks for reply, you used to man of many words, now man of few words!
These particular Danfoss valves have two valve seats, one smaller one to allow easier opening against pressure.
In real terms valve direction is not critical if sized correctly or not.
I personally don't like the idea of valve gland live on liquid lines or hot gas.
While servicing & it later leaks, your in trouble straight up while you are cleaning a strainer, solenoid etc.Last edited by RANGER1; 16-04-2019 at 09:06 PM.