As a DIY’er I occasionally need to install, modify, or repair plumbing items. This past weekend reminded me how frustrating plumbing work can be. I installed a new water heater that had 1″ nipples, and no drain port, so I needed to assemble some threaded adapters. I used brass and bronze parts, buttered with PTFE paste. All worked fine except a 3/4″ short nipple screwed into a 3/4 x 1″ bushing. It had a 1-second drip as soon as the pressure was applied. I tightened the nipple in steps until it got too hard to maintain a bite on the brass. The leak never even slowed down. Do bushings crack easily? That’s about all I can guess might be wrong. I seem to have this problem every time I use threaded couplings, although switching to paste has helped a lot. I’m never sure how tight to torque them. Any tips? Thanks!
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Bought the unit at HD?
I had that problem once.
Bought a replacement at the local hardware store and put them both on a micrometer. HD product was more than .020 smaller od. No wonder it wouldn't stop leaking.
POS chinese junk.
Sometimes you get bad threads that just wanna leak. In those cases, I use a liberal application of RectorSeal in addition to 3 or 4 wraps of teflon tape. Belt & suspenders.
Mike Hennessy
Pittsburgh, PA
Thanks, Mike. I'll look it up. I sure wish I could avoid the leaks in the first place. I hate doing a job twice.
You've run into one of the three rules of plumbing:
1] Now matter how tight you get it, it will still leak.
2] No matter how hard you try to loosen a threaded joint, it will be rusted solid and won't budge.
3] The blockage in your sewer will always be one foot further down than the length of your snake.
~Peter
I've had cast brass/bronze fittings with impurities in the metal that caused a leak right through the side of the fitting. (Also had a similar problem with a water leak in my wife's old Gremlin -- an impurity in the casting caused a slow leak, pretty much from the start.)
But otherwise, using mostly teflon tape, I've rarely had trouble with threaded fittings.
How,
I have had the best luck when I put some of the teflon past in the female side of the fitting along with putting it on the male threads. In reality, a pipe thread should not need a lot of sealant because the tapered threads should seal it, but in the real world .....
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
I will second the usage of teflon tape as I use it on alot of automotive applications too. But I like to use the pink tape which is thicker and seems to fill the threads better.
Bushings do crack. I had one on the water separator in my boat and I didn't really figure it out until I took it apart. Tightening the bushing into the housing squeezed the crack together until it was closed up tight but it still had a very slow leak. Not a good thing with gasoline.
In retrospect I would say you put the bushing in and tighten it up, then put in the smaller pipe. That would support the outer diameter of the fitting and it might not crack. I have always just screwed everything together and tightened as a unit. I bet the inner went in faster than the outer and put all the stress on the thin bushing walls.
Edited 11/10/2008 8:39 pm ET by gfretwell