rigid conduit

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ultramegabob said:
ridgid makes dies that can be straight or taperd with a flip of a lever.
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So for 2000 bucks I could make conduit threads wrong.

This whole thread is goofy.

But what I really want to know is ,..Are the threads on rigid couduit threaded:confused: :grin:
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Yeah... I'd like to know that too. :roll:
 
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realolman said:
So for 2000 bucks I could make conduit threads wrong.

This whole thread is goofy.
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all I know is when I worked for another company about 10 years ago, we ran alot of ridgid pipe, we could thread either way, and alot of people have told me I was nuts for saying so. I dont know If we were installing against code back then or not, I dont know if conduit has always supposed to been tapered, but we always cut straight threads for lock nuts. and I dont think this thread is goofy, there seems to be alot of confusion on this topic, its good to know what can and cant be done, and what is legal by code....
 
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realolman said:
I also don't see how a single set of dies could cut running and tapered threads of with the correct profile.
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Just keep running the NPT die down the conduit, you get usable running threads.
 
I am aware of that. the last (first?) 3/4" will be tapered.

And the wall of the conduit will be thinner. And it will be a code violation.

Seems to me the tapered dies are made to form the threads when the entire die is engaged. I don't know what profile the last "tooth" of the die will make on the "running" threads.

And I don't know why you'd want to do that anyway. Do you want to make 2 " of threads and have 1" stick outta the coupling? What's the point?:confused:
 
Running threads are permitted, if not used at a coupling. Back in the days when everything was rigid conduit guys would make a long thread, install a locknut and then install the coupling over the entire thread. Next they would line up the next piece of conduit and thread the coupling over it. The last piece of the puzzle was to tighten the locknut against the coupling to hold it in place. This was commonly called at the time a "depression coupling" named that since the proper fittings were too expensive.

Running threads can be uses between two pieces of equipment, boxes, meter can/panel etc.
 
Think of a pipe with a running thread as a cut-to-length nipple, kinda like all-thread is a cut-to-length bolt.
 
Somebody back a few pages hit it.... tapered to allow gases to escape and cool off some before entering a potential explosive atmosphere outside the conduit. Most Div 1, Class 1 type jobs required rigid conduit for the wiring type and hot gases could start a big bang if a fire started inside the conduit run and gas escapes. Thats what I was taught, and also have read about it, maybe Croft or Ricter?
 
infinity said:
Running threads are permitted, if not used at a coupling. Back in the days when everything was rigid conduit guys would make a long thread, install a locknut and then install the coupling over the entire thread. Next they would line [it] up [with] the next piece of conduit and thread the coupling over it. The last piece of the puzzle was to tighten the locknut against the coupling to hold it in place. This was commonly called at the time a "depression coupling" named that since the proper fittings were too expensive.
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In other words, an inexpensive two-piece alternative for a three-piece coupling.

FWIW, when cutting running threads with adjustable-size die heads, you can cut the threads to the shallow side of nominal for use with couplings and locknuts, perhaps some threaded bushings, most likely not for conduit bodies. This provides greater contact of mating threads and thus a better connection, both electrically and mechanically.
 
Smart $ said:
In other words, an inexpensive two-piece alternative for a three-piece coupling.
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Ah, an Ericson coupling; the electrical version of a plumbing union.
 
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