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Removing a stubborn steam plug

branimalbranimal Member Posts: 31
I’ve got an extra steam radiator that I’d like to install where one was installed at some point. The steam pipe is plugged with a 1/2 plug. I’ve hit it with heat for 1 minute and tried to open it with my wrench, no luck. I’m afraid to break the plug. Any suggestions?

And what is that bell shaped thing below the plug?

My replacement plan is a 1/2 close black nipple attached to a 1/2” female x 1” male fitting. That’s the best I could find in my hardware store. My radiator valve is 1” female.


  • ethicalpaulethicalpaul Member Posts: 343
    Try a good penetrating oil, applied several times over a few days. The bell thing looks like a reducer, maybe the pipe is the same size as the one next to it?
    1 pipe Utica 112 in Cedar Grove, NJ. If you see me say something dumb, just think of my poor wife--she has to hear it every day!
  • branimalbranimal Member Posts: 31
    Thanks I’ll hit it with some pb blaster
  • SailahSailah Member Posts: 766
    You need bigger tools than a pair of channel locks. Heat the outside to get thermal differential working for you, then ice down the plug to shrink it. That differential shock helps break the rust bond. Then hit it with Kroil/PB Blaster when it is still warm to draw the oil in. Keep at this for a few cycles. Then on the last, shock it and lean into it with a couple big wrenches.

    I find impacts to work better in these situations but you'd need a square socket and a big impact. My 18V 1/2" anvil Makita buzzes those things out like they weren't even stuck.
    Peter Owens
  • branimalbranimal Member Posts: 31
    I tried with a 12" pipe wrench.

    I'll use your heat/cool/oil method with an 18" pipe wrench.
  • JUGHNEJUGHNE Member Posts: 5,112
    Assuming this is one pipe steam.
    IMO I believe you need to remove the reducing coupling and use the full size pipe. Adding the 1/2" nipple and then increasing to valve size will create a bottleneck (actually an hourglass) to cause water hammer.

    Do you have access to the riser below?
  • KC_JonesKC_Jones Member Posts: 3,896
    @JUGHNE has it. Ignore that plug, the bell reducer needs to come off as well. 1/2" piping doesn't belong on a 1 pipe system. They probably did it that way because the fittings were laying around so they used them, I only suggest that based on my past experience doing just that.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 4,699
    edited January 11
    As @jughne & @KC_Jones mentioned the reducer needs to come off. They didn't have the right size cap so they put a reducer on and plugged it.

  • Intplm.Intplm. Member Posts: 54
    Do you have two PIPE WRENCHES? 18" or greater in size will turn that reducing coupling. Or larger if you can get them. But you should use two. One as a backer the other to loosen.
    Can you pull the fitting reducer up off the floor by hand?
    If you can, place one wrench between the fitting reducer and the floor on to the pipe, the other wrench on the fitting reducer.
    If you can't pull the reducer up a little from the floor, hopefully you can access the pipe from below . You will need some help.One person holding one wrench from below and the other loosening from above.
    If those things don't work, you can try turning with just one wrench from above as a last resort. This can turn the pipe in the floor that is not exposed and create more problems so hopefully you can get it from the other recommendations.
    ("lefty loosey righty tighty").
    Good luck. Please post your end results.
  • nicholas bonham-carternicholas bonham-carter Member Posts: 7,606
    What about cracking the fitting with 2 big hammers, or making lateral cuts in it to relieve the hold on the threads.
    Put a big pair of vice-grips on the pipe in case it wants to fall down the hole under the floor.—NBC
  • Intplm.Intplm. Member Posts: 54
    Doesn't look like a BCI fitting. Looks malleable....?
    Would be better if it's black cast iron.
  • PumpguyPumpguy Member Posts: 340
    One useful trick not mentioned is to hit the plug a few good whacks with a hefty hammer. The impact shock is frequently all that is needed to loosen things up.
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  • JUGHNEJUGHNE Member Posts: 5,112
    Probably cast iron swing 90's under the floor.
    Those would "whack crack".

    I did crack a CI tee unscrewing a nipple. Didn't show up until I tried to reuse for new nipple.
  • branimalbranimal Member Posts: 31
    Yes its a one pipe system.

    I cannot pull the reducer fitting up. Won't budge.

    I can ask my tenant below to access through his ceiling.

    I've got a 12" and an 18" wrench. I'll give that route a try.

    I recently moved a 2" CI steam pipe and I needed to put relief cuts in the couplings and hammer and chisel it out. The pipe threads were in good shape afterwards.

    Regarding the water hammer... i disconnected a radiator yesterday and it had maybe 30 ounces of water in it because the pitch was terrible. But it never hammered. I thought water in the radiators made them hammer?
  • ethicalpaulethicalpaul Member Posts: 343
    edited January 12
    It _can_, but I’ve given up being sure about such things 😂
    1 pipe Utica 112 in Cedar Grove, NJ. If you see me say something dumb, just think of my poor wife--she has to hear it every day!
  • nicholas bonham-carternicholas bonham-carter Member Posts: 7,606
    edited January 12
    Have you described your main steam boiler piping, as that can throw up a lot of water, if it is not correct, especially if the pressure is too high, and the main venting is inadequate.—NBC
  • Intplm.Intplm. Member Posts: 54
    Use the 18" to loosen and the 14" as your backer below the floor if thats possible.
    Hope that you do not need to cut the fitting as you had before.
    Maybe put a cheater bar/long piece of pipe on the 18 to extend the leverage and make your turn.???
  • BobCBobC Member Posts: 4,882
    A few years back I replaced the anode rod on my gas hot water heater. It took a 24" breaker bar with a 1-1/16" six point socket and a four ft cheater on that 24" breaker bar. I ilso had a buddy trying to hold the tank but I still moved it.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • kcoppkcopp Member Posts: 3,229
    I would just cut it w/ a good Sawzall blade and after you get 7/8 through the fitting split it w/ a cold chisel.
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