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  1. #1
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    Multiple Expansion Valves



    Dear All,
    I have a questions about Multiple expansion vales. I found this article but don't understand how they operate. From the P-H diagram you can tell that this valve operates as a flush tank but I cant find a valve that can do this at no manufacture portfolio.
    Perhaps someone with more experience can help me with this.

    Please find following on page 7 the information I refer to:
    http://nptel.ac.in/courses/112105129...cture%2013.pdf

    The other parts of my system are exactly the same including, 1 stage compressor and 2 different temperature evaporators.
    Any feedback is highly appreciated.
    If you have any questions please let me know.

    Best regards
    Last edited by Brian_UK; 06-02-2017 at 05:31 PM. Reason: Post moved to correct section



  2. #2
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    Brian_UK is online now Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
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    Re: Multiple Expansion Valves

    Have you read any of the Sporlan documentation regarding expansion valves?

    http://sporlanonline.com/literature-...nal-materials/
    Brian - Newton Abbot, Devon, UK
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  3. #3
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    Re: Multiple Expansion Valves

    Hi SnowKing,
    As I understand it, the P-H diagram and the scheme do not match one to each other.
    As point 4 is the result from flash expansion, point 5 will be equal to point 4 and not liquid at saturation as indicated in the P-H diagram.
    The refrig cycle would be just like the one represented in Fig 13.2(a) &(b) - page 6.
    To have a P-H diagram like the one in 13.3 you need additional equipment, for instance a separator and a pump, and the output of evaporator-II would go to that separator.
    Hope that the explanation can be of some help.
    Regards,
    CDuque

  4. #4
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    Re: Multiple Expansion Valves

    Hi
    When you have expansion valve it means it is DX system
    With 1 compressor and 2 different temp
    You need kvp (evaporating pressure regulator ) in small system or PM 3 or pm 1 ( back pressure regulator ) in large system with other valves as you need
    You could find more information on danfoss web.
    Last edited by mbc; 11-02-2017 at 04:42 AM.

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