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breaking loose old steam pipe joints

mel rowe
mel rowe Member Posts: 324
Thanks Ed. I'm not quite sure what you had in mind. I'm trying to break loose a 10 ft. long piece of 2 1/2 in. pipe, so I can replace it with a shorter piece and make it work better with my new near boiler piping. If I can't get it loose I'll have to leave in place and work around it. Did you want me to try to cut the pipe and then work it loose? I've already got one end loose. It was in a union. I've used lots of WD 40 and a long pipe wrench, extended about 2 ft. with a piece of pipe for more leverage, but it won't budge. I'm even trying to rig it so that I can use my hydraulic jack to put force on the end of the wrench.


  • mel rowe
    mel rowe Member Posts: 324

    Well, I've tried everything I can think of and had no luck. Anybody have any magic way of breaking loose a 75 year old 2 1/2 in. steam pipe joint? I've been successful with all other joints but this one. Right now I'm stuck. Thanks.
  • mel rowe
    mel rowe Member Posts: 324

    I do have a reciprocating saw. Would it make sense to cut the pipe near the joint and then use the saw to cut most of the way through the pipe from the inside of the threaded part and try to break it out that way? I absolutely can't take a chance on damaging the connector, since the other side disappears into a crawl space I can't get into. Thanks.
    EBEBRATT-Ed Member Posts: 15,327

    If the fitting your trying to get it out of is cast iron you can break it with two hammers-one as a back up and one to smash with. You can also cut part way through it with a sawzall and drive an old screwdriver in it to open it up and unscrew it. Then install a new fitting and then your pipe. Trying to unscrew a 2 1/2" steam fitting that was not put on with teflon tape or never seize is pretty near imposible. You gotta cut something apart one way or the other. Yes you can saw the pipe off and cut the internal threads and pick it out with a chisle-don't cut too deep.


    BE CAREFUL AND WaRE SAFETY GLASSES THE CAST IRON CAN FLY! Get help from a professional if you havent done this before.
  • mel rowe
    mel rowe Member Posts: 324

    Ed, I really can't risk breaking or damaging the old connector. I just need to get the old pipe out of one side. Do you think it might be possible to cut the old pipe off and then use the saw to make several cuts from inside the pipe, deep enough to be able to bend it and break it out that way, without damaging the connector?
  • ed wallace
    ed wallace Member Posts: 1,613
    breaking loose old connecter

    yes use a sawzall to cut pipe close to connector then use sawzall or hack saw blade to cut old pipe inside of the connector if you make 3 cuts you can knock loose the old pipe

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  • Weezbo
    Weezbo Member Posts: 6,232
    you can machine it out *~/:)

    as a thought....
  • mel rowe
    mel rowe Member Posts: 324

    Thanks to all for the info and encouragement. I'll let you know how it works out.
  • garret_2
    garret_2 Member Posts: 1
    just a homeowner, but...

    pb blaster works a charm on my old steam pipes.


    I find wd40 almost useless for breaking old joints. My old man (the mechanic) agrees.. he's got 40 years experience working with old engines, and there isn't a can of wd40 in his shop.

    Spray the pb blaster, hit it with a ball peen, wait 15 minutes or so, spray again, then carefully give it some torque.

    I have a couple of 3 ft pieces of 2" diameter pipe that work wonders for carefully applying torque.. more tricks from the old man. He was born with one arm half useless, so he learned the tricks of torque and technique early...

  • ScottMP
    ScottMP Member Posts: 5,884

    Do you really need to save the connector ? Breaking them is common practice. I look for the seam of the fitting, where it was cast, and hit it there.

    If thats not possible then how about cutting it off, leaving a foot of pipe and then putting a thread on the short piece thats left ?

    I have had good luck with heating a fitting as hot as possible and then wrapping a cold wet rag around the pipe. This will cause the pipe to shrink and break the threads. You need TWO BIG wrenchs to do this. Sometimes with cheaters on the wrenchs.


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  • mel rowe
    mel rowe Member Posts: 324

    It worked. I cut the pipe off about 1 1/2 inches from the connector and then cut in three places from the inside of the pipe. Only nicked the threads in one place slightly-thank goodness. Then hammered on the pipe until it collapsed and broke away from the connector. Cleaned up the threads inside and it works like a charm. Appreciate all the help. This site is the best.
  • midway_2
    midway_2 Member Posts: 42

    glad to see you got it out, but was wondering , could you have sawed off about 6 inches from the joint, cut threads on the stump, and then used another union? Just wondering if that could be done?
  • Andy_17
    Andy_17 Member Posts: 30

    Next time try heat the joint, then take a candle & apply to the pipe just above the joint allow the wax to work in. Let it cool slightly, get your wrench on it & give it a few pulls. It will break free, work every time. Learned this from A old time steam fitter. Good luck
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