Results 1 to 9 of 9

Thread: Rack knowledge

  1. #1
    Join Date
    Jan 2007
    Location
    Southeast, GA / Jacksonville, FL
    Posts
    313
    Post Likes

    Rack knowledge

    Why does this hold back valve have a solenoid on it? I've only seen ones that don't have one and are manually set for a minimum pressure.

    Thanks
    Attached Images Attached Images  

  2. #2
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    1,605
    Post Likes
    Kind of hard to guess the piping arrangement does the store have heat reclaim or split condenser what type of defrost?
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  3. #3
    Join Date
    Jul 2000
    Location
    Guayaquil, EC
    Posts
    14,205
    Post Likes
    Quote Originally Posted by navyhydronics View Post
    Why does this hold back valve have a solenoid on it? I've only seen ones that don't have one and are manually set for a minimum pressure.

    Thanks
    Is it piped in the receiver bypass?

    The model number of the valve will tell you what it's function(s) are.

    That looks like an A81LB or A82LB Flocon valve. The L designates that it's a differential pressure regulator and the B designates that it's electric wide-opening...ie, when de-energized it acts as a differential regulator and energized the port opens fully.

    25-94B.PDF

  4. #4
    Join Date
    Jan 2007
    Location
    Southeast, GA / Jacksonville, FL
    Posts
    313
    Post Likes
    Thread Starter
    Its on the condenser return before the receiver bypass. This rack is electric defrost.

  5. #5
    Join Date
    Apr 2010
    Location
    California
    Posts
    616
    Post Likes
    Quote Originally Posted by navyhydronics View Post
    Its on the condenser return before the receiver bypass. This rack is electric defrost.
    Two terms i'm not familiar with, "Condensor Return", and "Hold Back Valve", so how about "Bypass Solenoid Valve"? Can you give us a bit more info., such as the rack application, brand, model #, etc.?
    Attached Images Attached Images  

  6. #6
    Join Date
    Jul 2000
    Location
    Guayaquil, EC
    Posts
    14,205
    Post Likes
    Quote Originally Posted by navyhydronics View Post
    Its on the condenser return before the receiver bypass. This rack is electric defrost.
    Thanks, I couldn't tell from the picture.

    It looks to me to be the inlet pressure regulator (A8L/A81L) with the solenoid to open when energized. As I recall, this was used on some Tyler racks with a receiver bypass solenoid valve so when the receiver bypass was closed, the inlet regulator was energized open.

    Here'a a piping diagram showing this setup:

    5806448(PARALLEL-ENVIROGUARD-cvr-cont).qxd.pdf

  7. #7
    Join Date
    Jul 2000
    Location
    Guayaquil, EC
    Posts
    14,205
    Post Likes
    Quote Originally Posted by lzenglish View Post
    Two terms i'm not familiar with, "Condensor Return", and "Hold Back Valve", so how about "Bypass Solenoid Valve"? Can you give us a bit more info., such as the rack application, brand, model #, etc.?
    "Condenser return" is the liquid return line from the condenser.

    "Hold back valve" is another name for an inlet pressure regulator (IPR). An IPR in the condenser return would typically work in conjunction with an outlet pressure regulator (OPR) dumping discharge gas into the receiver for a form of head pressure control at low ambients.

  8. #8
    Join Date
    Apr 2010
    Location
    California
    Posts
    616
    Post Likes
    Quote Originally Posted by icemeister View Post
    "Condenser return" is the liquid return line from the condenser.

    "Hold back valve" is another name for an inlet pressure regulator (IPR). An IPR in the condenser return would typically work in conjunction with an outlet pressure regulator (OPR) dumping discharge gas into the receiver for a form of head pressure control at low ambients.
    Thanks for the reply Ice. I guess i missed the boat for this "hold back term" used "instead of prv", which is what it still is to me. Why we need another acronym is beyond me? As far as the condenser return term, in actuality i think you mean "return to condenser discharge line",but that is just another play on terms again i guess.? Anyway, as long as the OP understands is the main thing. Ok, give me both barrels now! LOL...PS: Don't get me wrong, I'm happy to learn this "new to me" "hold back term", and shall use it accordingly. Take Care!

  9. #9
    Join Date
    Jan 2007
    Location
    Southeast, GA / Jacksonville, FL
    Posts
    313
    Post Likes
    Thread Starter
    "It looks to me to be the inlet pressure regulator (A8L/A81L) with the solenoid to open when energized."

    That's what i thought. Thank you sir

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •