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Left-Hand Close Nipple?

Harry_6Harry_6 Posts: 82Member

Despite my best efforts I recently accidentally cut a plug out of a cast-iron wall-style flat radiator and discovered to my displeasure that I had removed one of the left-hand threaded (1-1/2") plugs. Now I know one can find L-R nipples and couplings, but this radiator is located in a niche in the wall just big enough for the radiator and some elbows. There is not enough room for a 4" L-R nipple (let alone the Ugly factor), but I could fit a 1-1/2" x close nipple, if one existed, and a 90. But does one exist? I can't find it. But I assume that's what they use when they assemble the sections of new radiators at the factory - so they do exist somewhere. And I have seen L-R "hex" fittings, but not NPT. I also thought of buying a L-R 4" nipple and cutting and threading it down on a pipe machine, but the logistics don't really work out. So what do the assembled geniuses who read this think?

PS - As a last resort I had wondered if I could bust up an old radiator for the L-R nipple, which ought to be 1-1/2", but that seems like an act of desperation. And of course no one makes a L-R plug either.


  • Larry WeingartenLarry Weingarten Posts: 1,524Member
    Hi, This idea may be an act of desperation also, but how about cutting the proper threads from a left-right nipple and welding a cap on the cut end? That would give you something to wrench on as well.

    Yours, Larry
  • PumpguyPumpguy Posts: 379Member
    Any machine shop with a thread cutting lathe could make one for you. The lathe should have a taper attachment, set to 3/4" per foot.

    On a lathe, it's just as easy to cut left hand threads as it is to cut right hand threads. Only difference is what direction the cutting tool travels.
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  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,914Member
    buy the 4" l-r nipple and have a welding shop cut and weld it back together shorter
  • Harry_6Harry_6 Posts: 82Member
    Thanks. All good ideas. Though I'm a little concerned that welding so close to the threads on such a small item, that the heat might distort it. Any others?
  • HenryHenry Posts: 914Member
    Try Shafter in Montreal but be prepared to pay!
  • Larry WeingartenLarry Weingarten Posts: 1,524Member
    Hi, If welding is a concern, you might try brazing. Perhaps buy two, so you can afford to ruin one! :p

    Yours, Larry
  • JohnNYJohnNY Posts: 2,289Member
    I’ve successfully repaired cut threads by using Hercules Pro-Poxy 20. Fill in the slice with a thin layer of the propoxy then run a nipple through the threads with a big wrench. It’s worked for me more than once.
    For installations, troubleshooting, and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
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