OK... We all know what the Code says:
Equipment:
A general term including material, fittings, devices, appliances, fixtures, apparatus, and the like used as a part of, or in connection with, an electrical installation.
Fitting:
An accessory such as a locknut, bushing, or other part of a wiring system that is intended primarily to perform a mechanical rather than electrical function.
Approval:
The conductor and equipment required or permitted by this Code shall be acceptable only if approved.
OK, it's a long intro for this:
http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1612840034&ccitem= (Sorry for the link - not sure how to post pic)
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).]
