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What is this and why

Discussion in 'Commercial' started by otto, Aug 11, 2017.

  1. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    I have a domestic water heat exchanger that is acting up. I suspect this device is malfunctioning but not sure what it is called and how it should be set. I think it is a two-purpose device, check valve and flow. Perhaps it only allows flow through the exchanger if the pump is running? The pump is on a limit on the discharge of the domestic so if it gets too hot it turns off pump and closes 3 way to stop boiler water. I may be mistaken on the piping diagram, going back today. The device is on a 1 1/4" pipe, cylindrical, red and has balancing ports on either end. Internal is a spring and a bell-like check. More pictures later. dom water exchanger.png
     
  2. knave

    knave Undeterred

    Messages:
    7,914
    Location:
    Out for a rip
    Are they using a recirc pump on the domestic side?

    It seems odd that they would use the outlet water temp instead of a sensor well in the tank.
     
  3. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    There is a recirc pump. There is no tank, the dom hot goes to the condo units then recircs back. It's a large condo building, 5 stories and maybe 200 units so the whole loop is the tank. Maintains 135° discharge.
     
    knave likes this.
  4. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    If I knew what the device was called I could probably learn more about it. I just need to know what it's called.
     
  5. pecmsg

    pecmsg Junior my ASS

    Messages:
    20,565
    Location:
    Eastern LI
    Try
    Thermostatic Control Valve
     
  6. pecmsg

    pecmsg Junior my ASS

    Messages:
    20,565
    Location:
    Eastern LI
  7. knave

    knave Undeterred

    Messages:
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    Location:
    Out for a rip
    Thought it was an indirect, lol.

    With pressure port on each end, it has to be a flow control, circuit setter, etc.

    Some are preset and not adjustable, but then you should have a GPM rating on the side somewhere.
     
  8. knave

    knave Undeterred

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    7,914
    Location:
    Out for a rip
    Does the mixing valve modulate to a preset temperature
     
  9. pecmsg

    pecmsg Junior my ASS

    Messages:
    20,565
    Location:
    Eastern LI
    Thats what im thinking.

    The pump shutting off is just a safety the valve controls the H W Supply
     
  10. pecmsg

    pecmsg Junior my ASS

    Messages:
    20,565
    Location:
    Eastern LI
  11. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    There is a tag that was hanging on the device since 1972 but is no longer legible.
     
  12. pecmsg

    pecmsg Junior my ASS

    Messages:
    20,565
    Location:
    Eastern LI
    Yes the 70's were a lot of fun............... Just wish i could remember most of it :headscratch:
     
    otto likes this.
  13. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    I am thinking if the pump shuts off this check prevents flow via the diff pressure between the boiler supply & return.
    The pump safety is a mechanical well limit. The 3 way is controlled by a T775 and a 2-10 actuator on a control loop.
     
    knave likes this.
  14. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    I am going back this morning. They had no hot water and can only get flow by running both primary loop pumps. The boilers provide baseboard heat for all the units in the winter. Only one primary pump should be needed in the summer since the heating loops are closed down. So with two primary pumps it is keeping the device open but beating the hell out of it.
     
  15. knave

    knave Undeterred

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    Location:
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    Some WSHP in office ceilings that I've worked on had non adjustable flow setters, cylindrical, a soft rubbery disc inside would regulate flow, more flow would squish it tighter against corrugated surface.

    They have lots of issues with plugging up.
     
  16. otto

    otto Bakery Chef

    Messages:
    19,825
    Location:
    in a van down by the river
    This job has 4 buildings all served by the two huge atmospheric boilers in one building. We replaced the heat exchangers in 3 of the other buildings. When they were replaced one of the devices cracked (cast iron) and it was replaced by a circuit setter. I may just do that and be done with it. I prefer to know what this is, why it's there and can I just replace it with a regular circuit setter.
     
  17. flange

    flange Act like you care and do SOMETHING!!

    Messages:
    12,790
    Location:
    IMT--in my truck
    Thermostatic mixing valve with remote bulb. It measures the leaving temperature of your domestic water using the remote bulb, which is gas charged and drives the actuator on the three way mixing valve to maintain desired temperature.
     
  18. flange

    flange Act like you care and do SOMETHING!!

    Messages:
    12,790
    Location:
    IMT--in my truck
    today it would be done differently, using a tempering valve where the leaving hot water goes ot one inlet, cold water to the other and the leaving water is tempered to maintain less than 130 degrees.
     
  19. frozensolid

    frozensolid Psychologist's Dream

    Messages:
    12,216
    Location:
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    I think Flange and Knave are correct. The building does not want to get sued by sending scalding water to the buildings. It may even be code.
     
  20. flange

    flange Act like you care and do SOMETHING!!

    Messages:
    12,790
    Location:
    IMT--in my truck
    It is a code requirement around here anyway these days. Back then it may have just been a good business practice I don't know I wasn't doing HVAC in 1972. Around here we can't send more than 120 up to the building so we typically store at a higher temperature to keep from organic growth then mix it down to about 1:18 going up to the building