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How Tight Do You Make A Fitting Connection?

Tom_22 Member Posts: 108
When installing pipe smaller than 2", when a fitting is not real tight but one turn more is hard to get out of it, do you wrench it around or leave it be?


  • tommyoil
    tommyoil Member Posts: 613
    I hammer 'em

    Had that same question once( a real long time ago) as the result of a heated debate. I called Grinnell and this is what I was told. With proper thread sealant they recommend the pipe turned three threads into the fitting should suffice. If you exceed three threads it should be tightened fully. I was never comfortable w/ the three thread method. Me, I always hammer 'em in and dont get leaks using this method. However, if you bury the threads you run the risk of splitting the fitting so watch out for that. I would undo the fitting in your case,re-dope it w/ dope and teflon and re-install it to a comfortable and happy medium. Check the other current thread here on the wall w/ regard to which pipe dope to use. There seems to be many opinions. Whichever method you use, no leaks should be your bottom line.
  • Robert O'Connor_7
    Robert O'Connor_7 Member Posts: 688

    I was taught that when making up the fitting it screws in HAND tight three turns (if not somethings wrong, give or take a half a turn) then make up 1 & 1/2 or until tight..Robert O'Connor/NJ
  • larry_9
    larry_9 Member Posts: 33

    It depends on the size of the fitting. If you read the teflon pipe dope can it says if you are using a fitting bigger than 1 1/2" to lightly dope the inside of the fitting too. the frist 3 threads, I find on bigger fittings that it seams to tighten then stops and if you back off the fitting it tears the inside of the fitting up. by lightly doping the inside I have less leaks and problems.
  • ScottMP
    ScottMP Member Posts: 5,884
    When I was an apprentice

    I asked the licensed plumber " How tight should this be ".

    His answer I will never forget " Tight is Tight ". I wanted to wrap the wrench around his head. What the hell does that mean I thought.

    It means its a feel. Its a touch. I don't believe there is any book or diagram that can tell you how tight it should be. Tight is Tight.

  • tommyoil
    tommyoil Member Posts: 613
    You said it !

    Excellent! Well put.
  • ernie_3
    ernie_3 Member Posts: 191

    I was taught...."When in doubt, go around again." Notice how the EZ port headers tighten up on the first go round....
    was up wit dat?
  • John MacGregor_3
    John MacGregor_3 Member Posts: 31
    How tight?

    6" of wrench per 1/2" of pipe and crank 'er down.
    i.e.; 1/2" pipe=6-8" wrench,
    3/4" =8-10",
    1" =12",
    1 1/4" =14",
    1 1/2" =18",
    2" =24",
    3" =36",
    4" =48".
    5" and up, Use a compound wrench or flanges.
    At least that's what I was taught 50 some years
    ago, and I think that's how those wrenches were designed.
This discussion has been closed.