Threaded pipe leaks

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by MushCreek, Sep 4, 2013.

  1. MushCreek

    MushCreek New Member

    Messages:
    34
    Location:
    Travelers Rest SC
    I just pressurized the supply in my new house. All the PEX is tight and dry, but the threaded connections are leaking, as usual. For each fixture, I used a drop-ear elbow with a threaded pipe nipple and a stop valve. Out of 11 such fittings, 4 of them leak where the stop valve connects to the pipe nipple. It seems like in recent years, I've had more and more trouble getting pipe fittings to seal- poor imported quality, I would guess.

    Any recommendations for a better seal? I've tried teflon tape, both regular and extra thick. I've tried several kinds of teflon pipe dope. Any ideas before I glue the fittings with some kind of epoxy??
  2. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    Tighten them properly.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,247
    Location:
    Cave Creek, Arizona
    Toss the TPFE tape, (there is no "Teflon" pipe tape), and use joint compound like I always do.
  4. asktom

    asktom Member

    Messages:
    589
    Location:
    Victor, MT
    Make sure the valves don't have hairline cracks. That can happen if they are overtightened.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,313
    Location:
    New England
    The quality of the fittings in general has gone down with most of them being imports, verses made here. To save that extra penny, they don't sharpen their tools as often, or adjust things for wear, so the threads can be really crappy. The tape has a harder time sealing than pipe dope when the threads are crappy, as if they are rough, it can cut or tear the tape. The pipe dope fills in those voids better; just make sure to got a good coat all the way around. But, it could easily be you just didn't tighten them enough.
  6. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,185
    Location:
    NW Ontario, Canada
    Damned if you do, damned if you don't. I had a thread fitting that I had to torque the crap out of to stop it from dripping. Low and behold, 10 years later it decided to crack and flooded my crawlspace.

    I stopped using tape decades ago and only use joint compound now.
  7. craigpump

    craigpump Well-Known Member

    Messages:
    1,080
    Location:
    ct
    We have the best luck using a few wraps of Teflon tape and then coating the tape with RectorSeal.

    Yeah I know it sounds like overkill, but our tank installations don't leak.
  8. Terry

    Terry Administrator Staff Member

    Messages:
    15,416
    Location:
    Bothell, Washington
    It's like religion.
    Many ways to the same goal.
    I've done it every way I can think of and made them all work.

    If it's done tight enough, even rubbing a bar of soap on the threads is going to work.
  9. dj2

    dj2 Member

    Messages:
    437
    Location:
    California
    That's exactly what I usually do.

    Make sure you thread the shower arm correctly. Done correctly I don't see how you will get a leak.
  10. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    Personally, I hate tape. Never use it for anything. I use rector seal #5 for damn near everything. Not a fan of Teflon compounds either. It's too easy to over tighten the joint and damage things.
  11. MushCreek

    MushCreek New Member

    Messages:
    34
    Location:
    Travelers Rest SC
    I've even had leaks with RectorSeal. How tight is tight enough? I used the big 17" Channelocks, and I'm a pretty strong guy. Much more, and I'd probably split the fitting. Reminds me of a Mitsubishi car I once had. The factory oil filter had the instructions, "Tighten enough". While we're at it, how DO you tighten stop valves up without chewing up the nice chrome? There isn't enough flat area for a wrench.
  12. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,309
    Location:
    Maine
    Hmmmm. Did ya use them 17 inchers the 1st time? An 8" adjustable is plenty. Perhaps you ovaled the nipple with them big honking channel locks in which case..... It's new nipple and probably valve time.
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