I remembered one of my foremen when I first started who had a tray of nipples similar to this one - a tray of 1/2", and a tray of 3/4". All galvanized, varying in lengths from close to 6". We used them for going through exterior walls for A/C disconnects and exterior W/P receptacle boxes, as it tool less time (and a smaller hole) than messing around with compression fittings.
Thinking back now, I don't remember them being UL listed (no little blue & silver sticker), and I now wonder if he was using regular "plumbing" nipples instead of UL "electrical" nipples. We made sure the ends were reamed smooth and everything was secure, and I don't remember getting red tagged on it.
Does anybody have a supplier who offer a pre-sorted "selection" of Listed nipples of various lengths like they have for plumbers? Has anybody used a plumbing nipple in a pinch?
Just being curious.
[This message has been edited by DougW (edited 11-04-2004).]
... I thought "running threads" were a violation.I remember reading in the "good book",.."no running threads,and no more than a 3/4"/ft taper on threads...What exactly are running threads,..is it like a long close nipple?? Honestly,I'm confused,..as I don't do much work with rigid pipe,but I'd still like to know....Thanx, Russ
.."if it ain't fixed,don't break it...call a Licensed Electrician"
Re: Use of plumbing fittings...#44457 11/04/0410:37 PM11/04/0410:37 PM
342.42(B) and 344.42(B) states that running thread is only prohibited when used to connect couplings. Must mean running thread can be used anywhere else. I may just look into using running thread. Nice to learn new techniques through this site. Ron
Re: Use of plumbing fittings...#44458 11/05/0407:41 AM11/05/0407:41 AM
I have to confess to using plumbing nipples occasionally when I was "needy". They were always reamed carefully to take off the nasty sharp edge.
What exactly are running threads,..is it like a long close nipple??
Russ, running threads are sometimes called "allthread", too. It's just a piece of GRc with a continuous thread. It's usually sold in 3 foot sections (and costs a lot). Standard pipe threads have a taper of 3/4" per foot. Running thread has no taper, the threads are straight. It's great stuff for cutting into short lengths for use with locknuts for connecting enclosures together, etc.; an "adjustable nipple", so to speak. Conduit couplings, unlike plumbing fittings, are also made with a straight thread. You can take one and spin it all the way up and down a piece of running thread much like a nut would run up a piece of threaded rod.
Re: Use of plumbing fittings...#44459 11/05/0401:25 PM11/05/0401:25 PM
Nipples can be bought per size or made to fit. Rigid metal conduit is UL approved, you just have to cut to length and make sure it is reamed and threaded properly.
Now using black steel pipe has been a big no-no every place I have ever worked. I have done alot of work on Explosion Proof and just using nipples to get through walls. I don't use continous threads, especially on mobile equipment where vibration can cause couplers/locknuts to walk off of the fitting.
Re: Use of plumbing fittings...#44460 11/06/0407:36 PM11/06/0407:36 PM
When I first started "Expolsion-Proof" work in 1984, I remember there being a "UL" sticker on each and every nipple (Galvanized Rigid Steel) that we bought. At the time, it seemed excessive. I guess the manufacturers thought so too, because come to think of it, I don't recall seeing the stickers for at least several years.
Re: Use of plumbing fittings...#44461 11/06/0407:47 PM11/06/0407:47 PM