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Looking for feedback on repiping Dunkirk boiler

slater
slater Member Posts: 19
edited May 2015 in Strictly Steam
I am getting ready to repipe a Dunkirk boiler and have a concern with the configuration when I come off of the header. The current configuration has what I think is a bullhead. The riser comes up and across and into a tee. One direction the main continues on and increases from 2" to 2-1/2. it was reduced out of boiler when installed. That main continues about 75' and dumps into a Hoffman #55. The other direction out of the tee it runs 2" for approx. 11' reduces to 1-1/4 to go feed a radiator on the second floor. One question I have is can this feed that runs upstairs be tied right into the header? The pitch is uphill away from boiler and some condensate would have to trickle back into header. I plan on rotating boiler 180deg so you can actually access controls and add a cleanout tee and repipe using 2 risers with original install specs. Also removing watchman condensate pump. I'm adding some pics for illustration.

Comments

  • SWEI
    SWEI Member Posts: 7,356
    With the age of that boiler, I would give it a serious leak test before I spent the time and money required to repipe it properly.

    Are you sure the condensate pump is actually necessary?
  • slater
    slater Member Posts: 19
    The boiler was new in 89. The condensate is not necessary and plan on removing. The system has been running years somehow without it working. Found wire broke off of mercury float switch in low water cutoff. Friend/owner does not remember it ever working. He has lived there 17yrs.
  • slater
    slater Member Posts: 19
    Hatterasguy I plan on putting in a proper header and equalizer. I posted a pic on the manufactures specs and plan on building it to spec. This was installed by a not so qualified Sears installer. I've been told there is only maybe 12 steam units in town and all they want to do is rip it out and put in forced air. My concern is it a problem to hooking up the 2" pipe that runs to Seccond floor to a separate steam riser with the pitch running up hill away from header. Does it hurt if condensate makes its way back into header. The pipe going other direction is pitched down hill slightly all the way to the Hoffman trap. Pic labeled #4 shows a view. Don't know if this is an issue maybe overthinking it.
  • Steamhead
    Steamhead Member Posts: 16,796
    slater said:

    I've been told there is only maybe 12 steam units in town and all they want to do is rip it out and put in forced air.

    Congratulations for not going along with that stupidity.
    slater said:

    My concern is it a problem to hooking up the 2" pipe that runs to Seccond floor to a separate steam riser with the pitch running up hill away from header. Does it hurt if condensate makes its way back into header. The pipe going other direction is pitched down hill slightly all the way to the Hoffman trap. Pic labeled #4 shows a view. Don't know if this is an issue maybe overthinking it.

    What I'd do is start at the existing 2-1/2" main and build backwards. Put in a tee for that 2" runout to the 2nd floor rad (how big is that rad anyway?) and the condensate will drain to the end of the 2-1/2" main. Continue toward the boiler, adding a tee where that small runout comes in, then drop to where your header will be.

    And vent the heck out of that main!

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • slater
    slater Member Posts: 19
    edited May 2015
    Steamhead said:


    What I'd do is start at the existing 2-1/2" main and build backwards. Put in a tee for that 2" runout to the 2nd floor rad (how big is that rad anyway?) and the condensate will drain to the end of the 2-1/2" main. Continue toward the boiler, adding a tee where that small runout comes in, then drop to where your header will be.

    And vent the heck out of that main!

    That sounds like a simple solution that will alleviate my concern. the radiator measures 26"wx38"t has 10fins and looking at end has 3 columns approximately 2"wide. As far as venting the only vents I have seen are on the wet return. I have not seen any provisions for any on the main. The end of the main ties into Hoffman #55 trap. I am replacing the last 24' of main account boils on bottom edge of pipe so I could add a tee or two for vents. someone put a screw in it to plug a leak. Do you have any suggestions on what vents to use? I have noticed steam does reach the end of the main pretty fast. The Hoffman trap maybe stuck open and not working at this point.
  • Steamhead
    Steamhead Member Posts: 16,796
    That radiator is only 50 square feet EDR. Wonder why they used a 2" runout- maybe there was another one connected to it at some point?

    How long is the steam main, including the part that will be repiped, and is it all 2-1/2"?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • slater
    slater Member Posts: 19
    Steamhead said:

    That radiator is only 50 square feet EDR. Wonder why they used a 2" runout- maybe there was another one connected to it at some point?

    How long is the steam main, including the part that will be repiped, and is it all 2-1/2"?

    I went over and mapped out the mains and things don't look right to me but I'm not a steam expert. I'm wondering if this wasn't a hot water system at one time converted to steam. The pipe I discussed hooking into the header does more than thought after crawling under there where I could get a better view. I'm posting a drawing but I think I need to make some changes.
  • Steamhead
    Steamhead Member Posts: 16,796
    That explains why it's 2-inch. Can you add all the radiator runout connections to that drawing?

    Also, where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • slater
    slater Member Posts: 19
    Steamhead said:

    That explains why it's 2-inch. Can you add all the radiator runout connections to that drawing?

    Also, where are you located?

    I have added 2 pics one as is and the other of the changes that would make sense to me but I am not a steam expert. With all the loops and no vents seems to me the steam will flow to the point of least resistance and cause cold spots. We are located central Indiana.
  • Fred
    Fred Member Posts: 8,542
    Is this a steam system or a Hot Water system? Single pipe steam or two pipe? The proposed piping definitely doesn't look right for steam. No Header at the boiler, does not appear to have an equalizer, not sure where the condensate/dry and wet returns are. If steam, I would think loops (on a parellel flow) would return to the boiler as dry returns and drop down into wet returns. If it is a counter flow, I would expect to see some drip legs or other accommodations for return condensate.
    I would suggest you get a Pro in there to at least lay it out for you.
  • slater
    slater Member Posts: 19
    Fred said:

    Is this a steam system or a Hot Water system? Single pipe steam or two pipe? The proposed piping definitely doesn't look right for steam. No Header at the boiler, does not appear to have an equalizer, not sure where the condensate/dry and wet returns are. If steam, I would think loops (on a parellel flow) would return to the boiler as dry returns and drop down into wet returns. If it is a counter flow, I would expect to see some drip legs or other accommodations for return condensate.
    I would suggest you get a Pro in there to at least lay it out for you.

    This is a steam two pipe system that has a wet return that runs the outer perimeter of the steam mains and drains into a watchman condensate pump. The boiler is getting repiped with header, equalizer and doing away with the watchman pump. It sits next to boiler and there is no reason it can't be gravity fed. I plan on doing per manufacture specs shown on first post. It seems to be in line with everything I've studied and read on here.