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Fitting needed for Pete’s plug

zepfan Member Posts: 398
Does anyone know of a fitting that I can install on the Pete’s plug of a geothermal system? I don’t need it to balance, I need it as a place to pressure test, and fill. Thanks to all


  • ratio
    ratio Member Posts: 3,651
    You're looking for a "Pete's plug gauge adapter". Our local specialty controls supply house has them on the shelf. I'd imagine plumbing shops would too.
    EBEBRATT-Ed Member Posts: 15,620
    If you take the Pete's plug out the pipe thread is 1/8" IPS. You can put a nipple and a valve or whatever you want in there. You can't fill and drain through a Pete's plug it's too slow and too small an opening
  • hot_rod
    hot_rod Member Posts: 22,256
    It's not unlike the needle that you fill a ball with.

    Typically you get a 1/4" FPT thread to use a pressure or temperature gauge.
    The aluminum knurled tube is just to protect the needle.

    Moisten or lube the needle when you insert it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream