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straight thread connection?

jumperjumper Member Posts: 1,530
Know it's not done but I had to connect a female threaded valve to a straight thread (that is intended for compression). I coated the female with plumbers' grease and applied ample dope to male. It's holding pressure. Do I have to go back and do the job correctly or can I leave well enough alone?


  • icesailoricesailor Member Posts: 7,265

    Multiple wraps of Blue Monster Teflon tape PROPERLY APPLIED is a wonderful thing.
  • Mad Dog_2Mad Dog_2 Member Posts: 3,471
    In General ALL plumbing codes restrict.........

    the application of pipe dope to the MALE threads only. (although it is done sometime or another by most plumbers when they have a poor thread or are afraid of a leak). Also, Plumber's grease is not meant for lubricating standard pipe threads and joints. That being said.....let sleeping dogs lie.......Mad Dog
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  • icesailoricesailor Member Posts: 7,265
    ALL Plumbing Codes:

    I don't know about all OTHER plumbing codes, but I know of no requirement in the Massachusetts Unified Plumbing Code that states that pipe thread lubricant must be applied to ONLY the male portion of the pipe or fitting.

    I have never seen a Massachusetts plumber put pipe dope on the insides of a fitting. There may be some.

    I helped replace some boilers on an account where the mechanical company, rather than use Teflon Tape, "painted" both male and female ends of the fitting. That was the first and only time I ever saw anyone do it. After that (2000), whenever I had a particularly nasty connection to make, I smeared Rectorseal #5, Gasoila or BlueMol on the inside of the female side along with the Blue Monster tape and paste on the other male side, and that was that, Never a leak.

    My old dead boss used to talk about Glycerin & Litharge. It would stop any leak. You put it on both sides. Maybe we should go back to that stuff. He said that you could never get it apart. If they were cast iron fittings, they would crack before they came apart. So, out with the 4# hammer.
  • hot_rodhot_rod Member Posts: 14,040
    probably not a "code approved" connection anyway

    I don't think code allows for different types of threaded fittings to be assembled, without an approved transition fitting, regardless of the pipe dope method :)

    If it's not leaking and you have enough "purchase" on the threads to sleep at night....
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • icesailoricesailor Member Posts: 7,265
    edited March 2014

    That may be (an illegal connection).

    But if I am trying to connect something of European design, where the British Standard Thread (BST) is the Universal International Standard, except in the USA, where National Pipe Thread (NPT) is standard, it becomes a problem when I am say out in Webster, MA and the only supply house that stocks the BST/NPT adapter I need is in Boston, and I have to get it working in an hour, and the 1/2" NPT fitting is the same as the BST fitting, I'll improvise like most of us will. Multiple wraps of Teflon and Rectorseal #100 or Meg-Loc and I'm done.

    I have a set of Inch/Metric taps & Dies. There are TWO 1/8" taps. Both taps will fit in a 1/8" pipe fitting hole. But the BST is 27 TPI and the NPT is 28 TPI. Put the wrong one in and you wreck the threads beyond repaid. Unless you're willing to use Teflon tape. Which some refuse to do.

    Like the Metric System. It should have been adopted. Anyone here who can count money is already using the Metric System.

    How many "10's" in 100?  Answer, 10.

    How many "12's" in 100?  Answer,  8.33333.

    How many fingers do we have?  10.

    How many toes do we have?  10.

    What more can I say?

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