Pull a vacuum against a solenoid valve?
Page 1 of 3 123 LastLast
Results 1 to 13 of 31
  1. #1
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,308

    Pull a vacuum against a solenoid valve?

    I have some Tyler systems that are in need of filter/dryer changes. The problem is the piping is arranged like this:

    king valve>dryer>sight glass>service valve>solinoid valve.


    The problem is that once I close both valves to isolate the filter, I have no access to the system. If I use the service valve for access, I will be pulling a vacuum backwards against the solinoid valve. will a solinod valve prevent reverse flow? I wouldn't think so, but maybe I'm wrong.

  2. #2
    Join Date
    Sep 2001
    Location
    Rochester, New York
    Posts
    1,385
    Wouldn't front seating the service valve gain access between the king valve, drier and sightglass???

  3. #3
    Join Date
    Jan 2010
    Posts
    5,978
    Can you pump it down ?

  4. #4
    Join Date
    Sep 2007
    Location
    NH
    Posts
    1,125

  5. #5
    Join Date
    Jun 2009
    Location
    Upstate SC
    Posts
    1,439
    Are you changing cores or sealed driers? Couldn't you just put in a service port while you're doing the work?

    Sorry guys if none of this is relevant..... See edit
    Last edited by jdblack; 02-11-2010 at 08:05 PM. Reason: Didn't realize I was in ice making section

  6. #6
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,343
    You ain't gonna get a micron vacuum, but you will get most of the air out.


    I think you'd be better off pumping it down as other have suggested.

  7. #7
    Join Date
    Jun 2004
    Location
    Location:Raleigh NC
    Posts
    9,587
    I agree with pumping it down and/or also adding a service port
    If you help others then you are a Success

  8. #8
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,308
    I can pump it down to the reciever, no problem. The problem is pulling the vacuum. neither valve provides access to the filter/drier when they're in the position that isolates the filter. I could midseat the service valve, but that would require that the solenoid can prevent backflow.

    heres some pictures that I took a long time ago for another reason. If you combine what you see in the two pictures, you can figure out the piping arangement.


    Name:  IMG_1923.jpg
Views: 145
Size:  198.2 KB
    Name:  IMG_1925.jpg
Views: 129
Size:  153.3 KB

    I'm thinking the best thing to do might be to just braze a schraeder fitting right into the liquid line between the two valves.

  9. #9
    Join Date
    Sep 2001
    Location
    Rochester, New York
    Posts
    1,385
    Too bad they don't make liquid line driers with access ports.

    I've pulled many a vacuum against a liquid line solenoid valve with out any problems. I don't recommend, but it's surely been done before.

    Is it possible to just front seat the suction valve on the compressor once you pump it down??? If not, I'd do like you say, and install a valve in the liquid line.

  10. #10
    Join Date
    Feb 2010
    Location
    butler pa
    Posts
    1,073
    just sweat in an acess tee

  11. #11
    Join Date
    Jan 2010
    Location
    New Orleans metro area
    Posts
    161
    I would pull the charge and make the neccesary changes / improvements as needed . ( Old tymers used to say,,,Work on it as if one day you will again and you will always make a wise decision).

  12. #12
    Join Date
    Nov 2009
    Location
    Richmond, working under tarps
    Posts
    477
    front seat king valve, pump the liquid line down to say, 1-2 psig, change filter then evacuate. I don't see your problem.

    If you feel the compressor valves will leak, front seat the suction service valve.

    Again, unless i'm missing something, you don't have an issue there.

  13. #13
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,308
    Quote Originally Posted by indy2000 View Post
    front seat king valve, pump the liquid line down to say, 1-2 psig, change filter then evacuate. I don't see your problem.

    If you feel the compressor valves will leak, front seat the suction service valve.

    Again, unless i'm missing something, you don't have an issue there.
    If I do it that way, It would require pulling a vacuum on 150 feet of 5/8 liquid line and 1 3/8 suction line, plus some huge evaps. Not something I would look forward too, especially since 4 systems need the work done.

    I think I'm just gonna attempt to pull a vacuum against the solinoid valve, and if it doesn't work, braze in an access tee and pull the vacuum from that

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event