Rain tight couplings 3 inch

[wireddd]

Does anyone know of a manufacture that makes a 3 inch heavywall
setscrew coupling that is considered water tight for outdoor use?
We have to do a service run that requires the last elbow put on but it can't be threaded into a coupling, or any other suggestions as to how to join two threaded pieces without being able to thread them together in a coupling?

 

[masterinbama]

not a set screw but a 3 piece or even a compression are available from appleton

 

[realolman]

I guess an ericsson coupling union type thing would be too obvious. I must be missing something :?

 

[wireddd]

I can't find anyone who will say that an erickson fitting is listed as raintight
Appleton and Crouse Hinds both make a coupling with grounding straps
under the neoprene boot, but these are listed as explosion proof and are about $550.00 each.

 

[realolman]

Does this

do you any good?

 

[don_resqcapt19]

Rigid conduit couplings, standard or 3 piece, are not required to be listed as raintight. I'm not sure about the explosionproof one shown in realolman's post, but expect to pay about $100 for that in 3".
The fact that standard threaded conduit couplings leak more than the old compression EMT couplings makes me say that this whole raintight issue fro EMT fittings is bogus. I have no idea what prompted UL to make this move, but as I said it doesn't hold water for me.
Don

 

[sandsnow]

I have no idea what prompted UL to make this move, but as I said it doesn't hold water for me.
Don

Nice pun

Have you seen this??? http://www.ul.com/regulators/raintight.cfm

I question more and more the UL listing and follow up process, but that's a whole other topic.

 

[realolman]

I know this is a stupid question, but that never stopped me before.

There's no way this can be accomplished without some sort of union?

PVC is out?

The price of any union seems to be nuts at that size, if you can get it at all.

I'm just curious as to why there is not some other alternative.

( jacking up the building and sitting it down on your conduit )

 

[Awg-Dawg]

If you overthread your pipe, you can thread the coupling on it,then line up the pipe and 90, then thread the coupling on the 90.

 

[don_resqcapt19]

Awg-Dawg,

If you overthread your pipe, you can thread the coupling on it,then line up the pipe and 90, then thread the coupling on the 90.

See 344.42(B)

 

[james wuebker]

wireddd,
Check out Thomas & Betts. Red dot/ model no. EXFU-8. This is a union with female threads.
Jim

 

[Awg-Dawg]

Awg-Dawg,

If you overthread your pipe, you can thread the coupling on it,then line up the pipe and 90, then thread the coupling on the 90.

See 344.42(B)

Correction noted. Thanks Don.


Note to self, read big red book,read big red book.....

 

[wireddd]

Thanks for all the help. The concept of over threading the pipe is good as long as the inspector wouldn't consider this a piece of all thread or think the conduit isn't threaded in all the way and not allow it. All manufactures 3 piece couplings would work except for the listing. Not listed as raintite would not meet the inspection. One would think a threaded union would be just as tight as a standard threaded coupling.

 

[don_resqcapt19]

wireddd,

The concept of over threading the pipe is good as long as the inspector wouldn't consider this a piece of all thread or think the conduit isn't threaded in all the way and not allow it.

It is a code violation. 344.42(B).
Don

 

[ramsy]

My last use of a 4 inch rigid bender required threads be cut first, with a straight pipe, before bending, since the threader can't hold bent pipe. A side effect of this operation meant overthreading was the only way to achieve the shortest spec. 90's.

A few inches of this warped / threaded end had to be cut off before installation, but almost always resulted in visible threads, of the non-tapered variety, being visible beyond the coupling; technical code violations on several levels, but a necessary evil that informed AHJ's have understood and approved.

Don't AHJ's regularly approve this STD operating procedure for industrial applications. It seemed when studying for my 1999 NEC Cert., just like politician's diplomatic immunity, the NEC makes exceptions to just about every rule for industrial property.

 

[don_resqcapt19]

Roger,

Don't AHJ's regularly approve this STD operating procedure for industrial applications.

Not that I know of.

the NEC makes exceptions to just about every rule for industrial property.[/uote]
The code does not have an exception to this rule. The long threads make a very weak point in the conduit as a result of the depth of the threads. In normal installation the coupling is tightned up onto the taper of the thread, increasing the strength of the pipe and making the grounding connection. When the threads are cut long, the coupling remains on the deep cut threads and the strength is less and the grounding connection poor.

 

[ramsy]

Roger,
The code does not have an exception to this rule. ..When the threads are cut long, the coupling remains on the deep cut threads and the strength is less and the grounding connection poor.

I did'nt realize that. Perhaps my lack of seeing this violation enforced is mere coincidence.

However, on a different thread: http://www.mikeholt.com/codeForum/viewtopic.php?p=1182421#1182421
I tried to make the case, with my read of other industrial exceptions that riddle the NEC, it seems factories can just about be burning to the ground as long as its supervised.

 

[thinfool]

Maybe I missed something, but from what I gather of this question...I would consider a "split coupling". Similar to an OZ SSP-300. :!:

 

[tonyi]

This needed to be a raintight application. The OZ part is slick, but doesn't look like it could ever be raintight.