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Markets

Discussion in 'Commercial' started by pintofstout, Sep 26, 2017.

  1. pintofstout

    pintofstout New Member

    Messages:
    1,520
    Location:
    Olean, NY
    I'm at our local supermarket and i saw this new meat cooler. Saw a vacuum pump pulling through a manifold on a system with no micron gauge.

    Maybe he's going to check microns later. But the manifold? You guys pull through a manifold? Especially on an evap that was just piped in?

    Just curious. Not offended or calling him a hack, just was surprised to see this in a market. Their the pickiest of all in my experience.

    We're mostly ac and i don't think any of our guys pull through a manifold on something like a newly piped install....[​IMG]


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  2. crackertech

    crackertech assholiness *

    Messages:
    90,497
    Location:
    Fl/IN/Ga/Ms/TX/NJ/VA/NC/TN
    Not un common if it was a change out, but I would pull a vac from the rack not in the case,,,,,,or I would just purge that bitch :D
     
  3. Joeysmith

    Joeysmith New Member

    Messages:
    53
    I'll admit it. I pull through my 4 port manifold all the time. Hook 2 hoses to the pump and 2 to the system.
    Don't bring out the micron gauge every time but when I do it's never seemed slow to pull down. Let the beatings begin. :chairshot:
     
  4. mike1020

    mike1020 entitled millennial

    Messages:
    17,802
    Location:
    on the roof of target
    If the rack is on the roof I would pull from the case
     
  5. MNHVAC

    MNHVAC Man on a mission

    Messages:
    86
    Location:
    MN
    I'm working on my first triple evacuation on my trainer. (Still in school) Pretty cool stuff.
     
    Ballvalve79 and freeworld like this.
  6. frozensolid

    frozensolid Psychologist's Dream

    Messages:
    12,216
    Location:
    Earth
    I have to agree the lineset should still be full of vapor unless you pumped it down into a vac. Case should be dry and charged with nitro. So just get the nitro and any air out and you are golden. A vac pump on a circuit that is ball valved off almost always leaks some vapor. So a vac pump is not going to pull out moisture that is not in vapor form anyway.
     
    mike1020 likes this.
  7. pintofstout

    pintofstout New Member

    Messages:
    1,520
    Location:
    Olean, NY
    Huh. Ok. I just thought i was mainstream but I'm super anal.

    But.... How do you know it's a leak free system then? You guys use nitro?


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  8. frozensolid

    frozensolid Psychologist's Dream

    Messages:
    12,216
    Location:
    Earth
    In my case if the circuit was good before and the new case under pressure? The only doubt you should have is the welds you did. A mirror and ultimately a bit of soap will solve that part of the equation.
     
    Rather B Riding likes this.
  9. pecmsg

    pecmsg Junior my ASS

    Messages:
    20,564
    Location:
    Eastern LI
    Because were Professionals and never have leaks! :bowdown:
     
  10. Rather B Riding

    Rather B Riding Behind bars

    Messages:
    454
    I do nitro pressure test and I don't always use a micron gague.
     
  11. pintofstout

    pintofstout New Member

    Messages:
    1,520
    Location:
    Olean, NY
    Well, all the piping to this case is new, and the condensing unit out back is new. It's all new stuff.

    My thing is this- sometimes it takes me a half hour just to get set up with a rig that can pull and hold a deep vacuum against a closed valve. I'll go through a couple hoses sometimes or replace gasket or two before even opening up to the system.

    If you're picky about making sure your rig is even capable of pulling a deep vacuum, it turns out that it can be very difficult.

    The reason I'm so picky is simple- I'm too lazy to go get nitrogen, to constantly be swapping out cylinders, strapping them into my truck. I braze with it and put it away. leak proof with vacuum instead of positive.

    Of course, if something's pumped down somewhere on that system then that's different, those valves won't hold up to a vacuum.


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  12. frozensolid

    frozensolid Psychologist's Dream

    Messages:
    12,216
    Location:
    Earth
    The problem with that is if you have a leak you are pulling moisture into the system.
     
  13. mike1020

    mike1020 entitled millennial

    Messages:
    17,802
    Location:
    on the roof of target
    If it's valved off at the rack, the valves never hold. So if you use nitrogen you end up pushing the nitrogen into the low side. If you pull a vacuum you will never see a good micron level due to the valves leaking by.

    Best to just check all your joints with a mirror.
     
    392problemchild and LemonWizard like this.
  14. mike1020

    mike1020 entitled millennial

    Messages:
    17,802
    Location:
    on the roof of target
    We had a big problem with this.

    Someone forgot to braze a joint and pulled a vacuum for a long time and really contaminated the system with all the humid air that got pulled through the system.
     
  15. pintofstout

    pintofstout New Member

    Messages:
    1,520
    Location:
    Olean, NY
    That's obviously valid but I've just never had that issue. It's always been fairly quickly apparent if there's going to be a pre-existing leak somewhere out there. Then the nitro comes out, leak gets patched, and all that moisture is nullified.

    Actually i DID turn a system acidic over just a weekend of dragging in air, i have to cop to that since i posted about it here.... But that was one that I'd checked with nitrogen, and the vacuum collapsed a gasket off the peckerhead. That one was too large to leak check with vacuum.

    Aside from that though, works pretty well for me....


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  16. Chuck

    Chuck The Other Dude

    Messages:
    7,687
    Location:
    LAX
    I had to change a float in the oil seperator today. After valving everything off I still had a little gas flowing from a valve somewhere that wouldn't seat.

    It was continuously flowing out while I had the system open so I didn't get any air in. Didn't even vacuum at all this time, just opened things up and let it fly.

    #rackhack
     
    newtech, coldsnap, mike1020 and 3 others like this.
  17. pintofstout

    pintofstout New Member

    Messages:
    1,520
    Location:
    Olean, NY
    Yeah that defiantly changes the equation. I recently did similar thing on a DX chiller that wouldn't hold, but when i started it back up i had hot suction line and a babbling brook running through the sight glass.

    Turned out i had lost ONE HUNDRED pounds of 422d from that trickle. Eeh, maybe shoulda recovered that one.


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    Texas-Tech and Chuck like this.
  18. Chuck

    Chuck The Other Dude

    Messages:
    7,687
    Location:
    LAX
    Yes, not sure how much I lost but receiver level was not noticeably lower after I restarted it.
     
  19. Chuck

    Chuck The Other Dude

    Messages:
    7,687
    Location:
    LAX
    It's HP80 and I think we almost have the store owner convinced to let us change gas.
     
  20. pintofstout

    pintofstout New Member

    Messages:
    1,520
    Location:
    Olean, NY
    Ooh that stuffs expensive. Or maybe I'm thinking hot shot that's crazy expensive


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