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Thread: CDW Valves

  1. #1
    Join Date
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    CDW Valves

    Verify. Verify. Verify. CDW Valves were not scoped correctly and more importantly the Actuators were well below spec.
    Inlet doesn't have a manual valve, so a switch that interrupts the RIB Coil Common was installed. Not exactly a spool piece and new manual valve, but you have to get it done.

    Sent from my LG-M327 using Tapatalk

  2. #2
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    Why the reduction at the valve? What is that, 10" pipe with an 8" valve?
    -----Stop, step back, relax and have another go at it.-----

  3. Likes HVAC_Marc liked this post
  4. #3
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    Quote Originally Posted by AdrianOmarPerez View Post
    "but you have to get it done".
    MOVE IT TO WALL of SHAME ASAP !!
    Attached Thumbnails Attached Thumbnails 2se45x (2).jpg  

  5. #4
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    Thread Starter
    You should see this other place were the triple duty valve has no manual valve before it. 5 floors worth coming above the header.

    Sent from my LG-M327 using Tapatalk

  6. #5
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    Typically the CV flow characteristics of a full pipe size butterfly valve are too much flow. By going down one size the modulation swings are not as drastic, resulting in less hunting by the controls strategy. Any control valve should be carefully selected for the flow characteristics as most of the time a butterfly valve is nearly at full flow CV when positioned at 60% stroke. In this picture the valve may actually be correctly sized but utilizing an actuator that is too slow.

  7. #6
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    Quote Originally Posted by CCSPIERCE View Post
    Typically the CV flow characteristics of a full pipe size butterfly valve are too much flow. By going down one size the modulation swings are not as drastic, resulting in less hunting by the controls strategy. Any control valve should be carefully selected for the flow characteristics as most of the time a butterfly valve is nearly at full flow CV when positioned at 60% stroke. In this picture the valve may actually be correctly sized but utilizing an actuator that is too slow.

    Interesting CCSPIERCE. I have never seen this choking down, just to accommodate a valve size before? If this is as you say it is, then maybe i should defrost the crow, and do some digging. Thanks for Sharing.

  8. #7
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    Oct 2011
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    I should have mentioned that i was speaking in terms of this being a condenser pressure control operation. It was an assumption on my part that this was a condenser pressure control application as there is an isolation valve on the entering water piping.

  9. #8
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    Quote Originally Posted by CCSPIERCE View Post
    I should have mentioned that i was speaking in terms of this being a condenser pressure control operation. It was an assumption on my part that this was a condenser pressure control application as there is an isolation valve on the entering water piping.
    10/4, I will put the crow back on ice for now.

  10. #9
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    Apr 2003
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    Butterfly valves are terrible for flow control. Using smaller valves will help but your trying to control 5 floors and since its uninsulated pipe is it condenser water?

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