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  1. #1
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    What is the difference between a hot gas bypass valve, back pressure regulator and a constant pressure expansion valve?
    They all seem to do the same thing by opening on drop of outlet pressure
    Last edited by Drew; 19-11-2008 at 11:54 AM. Reason: delete



  2. #2
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    Re: Constant pressure or Hot Gas

    Hi Drew
    HGBPV simply bypasses the condenser into evap for defrost
    CPEV acts like a MOP TEV (maximum operating pressure) limmiting initial startup load, used on some chillers to prevent loading up to quickly causing shortcycling
    And the BPRV limits suction pressure at comp getting to high after a defrost
    So in short the CPEV closes on rise in pressure. I think thats right (correct me if Im wrong)

  3. #3
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    Re: Constant pressure or Hot Gas

    Thanks for the reply.
    Here is a link to a bit of info Ive found with regard to Pressure regulators and Back pressure regulators.:

    http://www.plastomatic.com/bprvspr.html

  4. #4
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    Re: Constant pressure or Hot Gas

    Sorry Drew I might have got it slightly wrong by the look of web site. Looks like Back Pressure RV controls upstream and Pressure RV controls downstream. Then we have normally open and normally closed valves. More comments on this appreciated.
    Thanks

  5. #5
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    Re: Constant pressure or Hot Gas

    So many brands, all with different desciptions of their valves. Does anyone know where I can get a brief overview of the different style of valves.

  6. #6
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    Brian_UK is offline Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
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    Re: Constant pressure or Hot Gas

    A good source of information is the old Sporlan site here...

    http://sporlan.jandrewschoen.com/literature.shtm
    Brian - Newton Abbot, Devon, UK
    Retired March 2015

  7. #7
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    Re: Constant pressure or Hot Gas

    thanks Brian_UK, just found out where Nike123 gets his field chart from ;-))

    Ice

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