Rigid Conduit

[jmellc]

I don't run much rigid at this time, I have run a lot with some bosses. I'm sure everyone else has seen this problem to a degree. Put a 90 or offset into the run, tighten wrench tight as code requires. Bend is not as needed. Loosen 1/4 turn, no longer wrench tight. Kill yourself getting another turn in the conduit, only other way to line up the bend. Code doesn't specifically forbid this, but would it be wrong to wrap threads with Teflon tape? That widens the margin of wrench tight. I've never tried it, never seen it done. But it would be a much easier way to line up the bends as needed, without straining muscles. I've put a meter on water & air lines with taped couplings, they ohm out just fine.

Thoughts?

 

[ceb58]

I see nothing in 334 that would prevent tape on the threads. The only fight with an inspector I see with it is if you are using it as an EGC. They may want to see some type report of the ohm value.

 

[Rockyd]

Wouldn't get too spun about it...long as it looks good (within a turn), it should fly, howq much protection does that wire need (assuming that is why it is in the GRC)? Bet it [strike]grounds[/strike] bonds better than a # 10 ground wire would even in sloppy coupling

 

[iwire]

Bend is not as needed. Loosen 1/4 turn, no longer wrench tight.

There is no general requirement for it to be wrench tight in ordinary locations.

 

[jeremysterling]

I would put a locknut jam to the coupling.

Or, toss the coupling and install a union.

I don't think I would use tape in that situation.

 

[LarryFine]

Replace the coupling with an Erickson.

 

[roger]

Replace the coupling with an Erickson.

Not very practical or economical if there are 100's of runs.

Roger

 

[LarryFine]

Not very practical or economical if there are 100's of runs.

Well, I did say "an Erickson."

What would you recommend?

 

[roger]

Well, I did say "an Erickson."

What would you recommend?

See Iwire's post above. We run thousands of feet of RMC each year and we normally manage to screw bends and offsets together tightly with large adjustable pliers, strap wrenches, (Rob Roy) and pipe wrenches.

I admit that there are times when an Erickson, threadless, or split coupling may be needed but that is a rare exception, not the general rule.

Roger

 

[220/221]

Put a 90 or offset into the run, tighten wrench tight as code requires. Bend is not as needed. Loosen 1/4 turn, no longer wrench tight.

Sure it is.

"Wrench tight" doesn't mean "as tight as it can possibly go with a wrench". It means "more than hand tight.....put a wrench on it"

You have about 3/4" of threads conected. Don't be concerned about 1/4 turn.

 

[josephteel]

Lock and seal

Lock and seal

Use lock tight/lock and seal

 

[hurk27]

Well, I did say "an Erickson."

What would you recommend?

threadless connectors?

 

[Smart $]

Sure it is.

"Wrench tight" doesn't mean "as tight as it can possibly go with a wrench". It means "more than hand tight.....put a wrench on it"

You have about 3/4" of threads conected. Don't be concerned about 1/4 turn.

Agree on wrench tight... just tight enough to not be able to turn (without leverage) by hand.

...and 3/4" of threads connected is only proper for max tight 2", handtight 3". Those who spec tightened to no threads showing are lacking in the knowledge department.

http://www.engineersedge.com/hardware/taper-pipe-threads.htm

 

[Smart $]

threadless connectors?

Disengage, crimp mid-section of male threads with v-grooved pliers, re-engage. This gaulds the threads such that a tighter joint is achieved at the desired rotation.

 

[infinity]

As Bob pointed out there is no NEC requirement for wrenchtight on a normal installation. The wrenchtight requirement is for special circumstances like classified installations or where the conduit is used for support to name a few.

 

[mtfallsmikey]

See Iwire's post above. We run thousands of feet of RMC each year and we normally manage to screw bends and offsets together tightly with large adjustable pliers, strap wrenches, (Rob Roy) and pipe wrenches.

I admit that there are times when an Erickson, threadless, or split coupling may be needed but that is a rare exception, not the general rule.

Roger

An electician with pipe wrenches is like a plumber with a megger...

 

[roger]

An electician with pipe wrenches is like a plumber with a megger...

Only if he's a very good plumber.

Roger

 

[Cow]

I carry a pipe wrench....

Sometimes you need it when you're busting old rigid conduit apart....

 

[sameguy]

chain wrench, pipe wrench, strap wrench, big channel locks, get it as tight as you can and it's good. If you over tighten then the pipe joint will bow or at a condulet will crush the end of the pipe down.

 

[Rockyd]

An electician with pipe wrenches is like a plumber with a megger...

Probably a pretty good guess that you haven't done much oil patch, or national defense work? One of the great things about the forum is the diversity of it in regard to solutions to problems when we're painting ourselves into corners