Filter drier / sight glass anyone?
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  1. #1
    Join Date
    Jul 2005
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    Hi guys! Curious what are your criteria for decision to install or not filter drier and/or sight glass? pro, cons Thanks!

  2. #2
    igwt777 is offline Professional Member - T&B bad email address
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    Jul 2005
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    Filter driers are a must for any refrigeration system. After pulling a deep vacuum and performing the correct procedures the filter drier will keep your system clean. Don't matter if is a new install or a compressor replacement, etc allways install a filter drier.

    Now talking about sight glass this have two main functions

    #1 To indicate if there is moisture

    #2 To indicate if there is a full column (clear eye, no bubbles) of refrigerant at the inlet of the TXV. Sight glass will give you better indication if installed just before the TXV ( and after the LL drier). In my opinion sight glass are useless on fixed metered systems (orifice or capillary) because sometimes you will see a "clear eye" but system still undercharged. Thats why always we must charge fixed metered systems using Superheat Method. TXV systems must be charged using Subcooling Method.

    igwt777

  3. #3
    Join Date
    Jul 2005
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    8
    I always install a LL drier if the unit doesn't come with one from the manufacturer, but most do nowadays. It's cheap insurance. Suction AND liquid driers on burnouts. Sight glasses usually only on commercial splits or refrigeration systems.

    Ed

  4. #4
    Join Date
    Jul 2005
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    10
    Not considering the cost another drawback seems to be increased chances of leakage. Do you blaze them or flare in place? I saw both types. What connection is better?

  5. #5
    Join Date
    Jun 2003
    Location
    Florida
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    Either connection will work well if properly done....as far as the sight glass goes most I've seen are installed at the condenser to monitor a full column of liquid back to the condenser,but I can see where you can put one up by the txv to see if it's flashing....
    If everything was always done "by the book"....the book would never change.

  6. #6
    igwt777 is offline Professional Member - T&B bad email address
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    Originally posted by smokin68
    Either connection will work well if properly done....as far as the sight glass goes most I've seen are installed at the condenser to monitor a full column of liquid back to the condenser,but I can see where you can put one up by the txv to see if it's flashing....
    Do you really want a full column of liquid back to the condenser????? Hmmmmmm...... I dont think that compressor will be performing at all.

  7. #7
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    Florida
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    Absolutely....the LL needs to be full.
    If everything was always done "by the book"....the book would never change.

  8. #8
    igwt777 is offline Professional Member - T&B bad email address
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    I agree with you.

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