# Ground joint union



## ICE

For the new inspectors...... the union on the right is a ground joint union and is not permitted in a concealed location.  Something else to watch for with gas pipe is Teflon tape.  If it is used, it must be yellow as this is listed for gas pipe and white is not.  I've read that the yellow is twice the thickness of the white.


----------



## jar546

It is my understanding that the coupling on the left is also not allowed in a concealed location.


----------



## fireguy

I did not think the location was concealed until it was covered, with sheet rock, insulation.

I did know the union had to be accessable, but had not heard that connectors were not allowed. What about 90° and other fittings.   How are you going to join the pipe without fittings?

I do know according to code, teflon pipe dope is not allowed because it is supposed to degrade in the presence of gas.  But, I have seen teflon pipe dope that has been in place for 30 years, without leaks.


----------



## ICE

fireguy said:
			
		

> °


   How did you do that for degrees?


----------



## mjesse

Ice,

hold "alt" key, and type "167"

Look-up "extended ASCII codes" for more symbols. ™, Æ, etc.


----------



## mark handler

ICE said:
			
		

> Something else to watch for with gas pipe is Teflon tape.  If it is used, it must be yellow as this is listed for gas pipe and white is not.  I've read that the yellow is twice the thickness of the white.


Water (White)

Steam (Pink)

Oil and Gas  (Yellow)


----------



## ICE

jar546 said:
			
		

> It is my understanding that the coupling on the left is also not allowed in a concealed location.


We need to get to the bottom on this one.  If what you say is correct, I have a been getting it wrong for years.


----------



## mark handler

ICE said:
			
		

> We need to get to the bottom on this one.  If what you say is correct, I have a been getting it wrong for years.


NOTE TO ALL THIS QUOTE IS FOR THOSE UNDER THE UPC NOT IPC

CPC 1211.3 Concealed Piping in Buildings.

1211.3.1 General. Gas piping in concealed locations shall be installed in accordance with this section. [NFPA

54:7.3.1]

1211.3.2 Connections. Where gas piping is to be concealed, unions, tubing fittings, *right and left couplings,* bushings, swing joints, and compression couplings made by combinations of fittings *shall not be used. *Connections shall be of the following type:

(1) Pipe fittings such as elbows, tees, and couplings.

(2) Joining tubing by brazing (See Section 1209.5.8.2).

(3) Fittings listed for use in concealed spaces that have been demonstrated to sustain, without leakage, any forces due to temperature expansion or contraction, vibration, or fatigue based on their geographic location, application, or operation.

(4) Where necessary to insert fittings in gas pipe that has been installed in a concealed location, the pipe shall be reconnected by welding, flanges, or the use of a ground joint union with the nut center-punched to prevent loosening by vibration. [NFPA 54:7.3.2]


----------



## Coug Dad

What's the difference between a "right and left coupling" and a "coupling" in exception 1?

OK, I Googled my own question.  The coupling as shown should be OK.


----------



## mark handler

IFGC-2006, the 2006 International Fuel Gas Code

404.3 Piping in concealed locations. Portions of a piping system installed in concealed locations *shall not have* unions, tubing fittings, *right and left couplings, *bushings, compression couplings and swing joints made by combinations of fittings.

Exceptions:

1. Tubing joined by brazing.

2. Fittings listed for use in concealed locations.


----------



## ICE

mjesse said:
			
		

> Ice,hold "alt" key, and type "167"
> 
> Look-up "extended ASCII codes" for more symbols. ™, Æ, etc.


Apple is different.  I have found a whole bunch of characters with the alt/option key and if I hold down the shift key too there's a bunch more. Option,shift,8 produces °,  option 0 produces º a bigger one.

`¡™£¢∞§¶•ªº–≠«‘“πøˆ¥†®´∑œåß∂ƒ©˙∆˚¬…æ÷≥≤µ˜∫√ç≈Ω¸˛Ç◊ı˜Â¯˘¿ÆÚÒÔÓ˝ÏÎÍÅŒ„´‰ˇÁ¨ˆØ∏”’»±—‚·°‡ﬂﬁ›‹€⁄

I don't even know what most of that stuff means.  I hope I'm not swearing in Arabic.


----------



## Coug Dad

A "coupling" is not the same as a "left - right coupling"

Section 404.3 does not prohibit couplings


----------



## mark handler

Coug Dad said:
			
		

> A "coupling" is not the same as a "left - right coupling"Section 404.3 does not prohibit couplings


yes       .


----------



## ICE

The coupling in the front is a standard coupling and the two in the second row are left/right couplings.  The difference is apparent and the one in the OP picture is a standard coupling.  There may be other couplings that look different than these but this is all I could find at Home Depot.


----------



## fireguy

Alt 0176 °

Alt 0167 §

The coupler in front is tapered, for use to couple pipes

The coupler back left looks like the coupler used by the electricians, straight thread.

The only left right coupler in my box of fittings does not look like that

I asked for a left right at HD once.  I was told there is no such fitting


----------



## north star

*= =*



Possibly "right hand threaded" or "left hand threaded"?

I too have never heard of a right or left coupling! 

*= =*


----------



## Dr. J

> Possibly "right hand threaded" or "left hand threaded"?


Yep.  With a coupling threaded lefty on one side and righty on the other, and the pipe to be joined threaded accordingly, one can turn the coupling and suck up the pipe tight, like a turnbuckle on a gate.  A left/right coupling is a cheater's union essentially.

The problem is that when someone turns the pipe with a pipe wrench further up the line, he could be unscrewing the lefty threaded part.


----------



## David Henderson

Probably depends on which hand you are using.


----------



## steveray

Just make sure you use the proper handed wrench.......


----------

