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  • #16
    Re: Bad pipe threads

    Originally posted by Vince the Plumber View Post
    how many turns of the fitting by hand before it gets tight?

    Vince

    if i recall correctly, about 2 full turns by hand.
    Three lose
    Three tight
    Three left
    Is how I was told so many years ago.
    Unfortunately it appears that I only have about two left on a proper joint.

    Comment


    • #17
      Re: Bad pipe threads

      Originally posted by drtyhands View Post
      Three lose
      Three tight
      Three left
      Is how I was told so many years ago.
      Unfortunately it appears that I only have about two left on a proper joint.
      maybe your just too darn strong.

      nurses love plumber's shoulders.

      i wrote that down, thanks.

      i recall one of the other members mentioning 3,3, and 3.

      Vince

      Comment


      • #18
        Re: Bad pipe threads

        it goes on the right amount
        Charlie

        My seek the peek fundraiser page
        http://observatory.mountwashington.o...nal&fr_id=1040


        http://www.mountwashington.org/weather/conditions.php

        new work pictures 12/09
        http://public.fotki.com/hvachawk/

        Comment


        • #19
          Re: Bad pipe threads

          Originally posted by DELCASE View Post
          Vince is just for the pic
          that pipe says USA
          Was it all your pipe or just the 1 1/2" ?
          I don't know yet honestly, I ran the 1 1/2 trunkline and got called to help out on another project, i'll know about the rest when I get back to that house next week.
          No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

          Comment


          • #20
            Re: Bad pipe threads

            don't know charlie

            but didn't you see how i hand threaded the 1'' black at the roundup

            rick.
            phoebe it is

            Comment


            • #21
              Re: Bad pipe threads

              Seems like the only thing you have not questioned is the dies themselves. Do you have another set you can try, or did you have the same problem before you went to the new die set?

              That first thread looks torn, but it could be happening as the pipe exits the die, not necessarily when the first thread begins cutting at the start.

              Are these hand cut, machine, or are you using a pony? Can't tell from the photos what the setup is. Looks like a you have a power head with hand dies from the little bit I can see in the one photo.
              ---------------
              Light is faster than sound. That's why some people seem really bright until you hear them speak.
              ---------------
              “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
              ---------
              "Its a table saw.... Do you know where your fingers are?"
              ---------
              sigpic http://www.helmetstohardhats.com/

              Comment


              • #22
                Re: Bad pipe threads

                Originally posted by PLUMBER RICK View Post
                don't know charlie

                but didn't you see how i hand threaded the 1'' black at the roundup

                rick.
                Wow Rick
                This is the first I've heard.Please tell me more.

                Comment


                • #23
                  Re: Bad pipe threads

                  Looks to me like he is threading with a 300 machine and hand dies with a bull pan oiler.

                  I have found that with some brand new dies do not cut very well out of the box until they have cut several sets of threads, seems like it burnishes the cutters or removes the burrs from the factory grind.

                  What kind of cutting oil are you using? and even if it is good quality oil it does wear out. Is there water in your oil?

                  I use a medium cutting oil that is high in sulfer and it works great on black steel pipe.

                  I try to get 3 to 3 1/2 turns by hand to set my dies with and two with a wrench to get it tight, should leave 2 to 3 threads showing. With the china fittings this is a real pain because they are not consistant at all.

                  Good luck

                  G3

                  Comment


                  • #24
                    Re: Bad pipe threads

                    After looking at your pics again the threads are not sharp on the ends and almost look bent over. I think you have some junk dies, try another set to make sure, or just put the old ones back in. What was the reason for putting in new dies? were they doing the same thing?

                    G3

                    Comment


                    • #25
                      Re: Bad pipe threads

                      The chart in the link below show # of hand tight turns and # of wrench turns. But they also throw in the caveat that in the field, thread are oftern not threaded as long as the "spec". I have often wondered if the cheap black pipe found everywhere these days...if they "cheat" on the wall thickness!


                      http://www.sizes.com/materls/pipeThrd.htm

                      Comment


                      • #26
                        Re: Bad pipe threads

                        i use a 300 machine , new oil , hand dies

                        Bob i will look next week when i do more threading if it is happening when i put it in reverse to take the die off


                        and rick no i did not see you do that remember i was not there that day
                        Charlie

                        My seek the peek fundraiser page
                        http://observatory.mountwashington.o...nal&fr_id=1040


                        http://www.mountwashington.org/weather/conditions.php

                        new work pictures 12/09
                        http://public.fotki.com/hvachawk/

                        Comment


                        • #27
                          Re: Bad pipe threads

                          Nicholson pipeliner, 60-30 triangle, little skill they can be salvaged. I've ran into that myself. ( where are they getting their ore from these days?) remember when it was brittle?

                          Comment


                          • #28
                            Re: Bad pipe threads

                            Originally posted by lovetheUSA View Post
                            The chart in the link below show # of hand tight turns and # of wrench turns. But they also throw in the caveat that in the field, thread are oftern not threaded as long as the "spec". I have often wondered if the cheap black pipe found everywhere these days...if they "cheat" on the wall thickness!


                            http://www.sizes.com/materls/pipeThrd.htm
                            Maybe wall thickness.But definately Alloys.
                            I used to be able to put some arm into tightening a 3/4" joint.Now I have to hold back and wait to feel where the pipe is at it's max seat right before it "Mauls"/strips out for an easy bury into the fitting.

                            Comment


                            • #29
                              Re: Bad pipe threads

                              Not sure where they came up with this chart but I would challange it.

                              1. PIPE is sized by the O.D., hence that is why it is called nominal pipe size and then is called out by its schedule number or wall thickness. If you measured it by the I.D. when the wall thickness changed the I.D. would also change.

                              2. The chart shows hand tight turns and if you look at the number of threads in their example diagram and what the chart call out, something does not add up. Starting with the two inch you run out of threads by the time you wrench tighten it.

                              3. The seal does not come from jamming the last threads of the pipe into the first threads of the fitting. Somewhere in the middle they will start to bind or jam to the point of "wedging" together to make a leak tight joint. The addition of pipe "dope" aids in the process of making the joint up, it provides lubrication and some even acts as a shim to take up all of the free space from imperfect threads.

                              At least that is my take on the situation along with the machinery's handbook.

                              Been making threads for 22 years and all of our piping is hydrostatic tested at 200 psi for two hours, even our CPVC!

                              G3

                              Comment


                              • #30
                                Re: Bad pipe threads

                                i will chock this one up to cheep pipe
                                Charlie

                                My seek the peek fundraiser page
                                http://observatory.mountwashington.o...nal&fr_id=1040


                                http://www.mountwashington.org/weather/conditions.php

                                new work pictures 12/09
                                http://public.fotki.com/hvachawk/

                                Comment

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