Use of left/right nipple and coupling

Posted by Wayne Whitney on February 16, 2006, 6:13 pm

Hello,

I'm looking for some guidance on the proper use of a left/right nipple
and coupling to join two rigid pipe assemblies. As I understand it,
the left-handed end of the L/R nipple and the threaded end of the
other pipe assembly should be in line with just a small gap between
them, maybe 1/4" for 3/4" iron pipe? Then you have pry them apart to
insert the L/R coupling, and tightening the coupling draws the two
threaded ends together. Do I have this right? It seems like the two
assemblies must have some give in them in order to be able to insert
the L/R coupling.

Thanks, Wayne

Posted by DanG on February 16, 2006, 6:46 pm

I am a little lost by your description. If you have two runs of
thread pipe that you are trying to join, I would use a union.

What is the material? What is the project? I think any of us
would need this information to help.
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
dgriff237@7cox.net

> Hello,
> I'm looking for some guidance on the proper use of a left/right
> nipple
> and coupling to join two rigid pipe assemblies. As I understand
> it,
> the left-handed end of the L/R nipple and the threaded end of
> the
> other pipe assembly should be in line with just a small gap
> between
> them, maybe 1/4" for 3/4" iron pipe? Then you have pry them
> apart to
> insert the L/R coupling, and tightening the coupling draws the
> two
> threaded ends together. Do I have this right? It seems like
> the two
> assemblies must have some give in them in order to be able to
> insert
> the L/R coupling.
> Thanks, Wayne
>

Posted by Wayne Whitney on February 16, 2006, 9:30 pm

> I am a little lost by your description. If you have two runs of
> thread pipe that you are trying to join, I would use a union.

I'm doing gas piping, and unions are only allowed in exposed
locations. So I need to use a left/right nipple and coupling, per the
inspector.

Thanks, Wayne

Posted by Wayne Whitney on February 17, 2006, 10:21 am

> I am a little lost by your description. If you have two runs of
> thread pipe that you are trying to join, I would use a union.

Not sure if I posted this already, but the inspector told me to use a
left/right coupling. I'm working on natural gas piping, so the use of
unions is limited.

Thanks, Wayne

Posted by PipeDown on February 16, 2006, 7:28 pm

> Hello,
> I'm looking for some guidance on the proper use of a left/right nipple
> and coupling to join two rigid pipe assemblies. As I understand it,
> the left-handed end of the L/R nipple and the threaded end of the
> other pipe assembly should be in line with just a small gap between
> them, maybe 1/4" for 3/4" iron pipe? Then you have pry them apart to
> insert the L/R coupling, and tightening the coupling draws the two
> threaded ends together. Do I have this right? It seems like the two
> assemblies must have some give in them in order to be able to insert
> the L/R coupling.
> Thanks, Wayne

Your description and assessment sound correct. As the other poster said, a
union would be the alternative method for joining two iron pipes together.
Just be sure to get the same metal (don't mix black pipe with galvinized
pipe even though they will fit).

I prefer a union because they can be opened and both ends tightened
independently if you have a leak. The nuts also are bigger making it easier
to hold onto with a couple of wrenches. THe pipes get pushed (in line) less
with a union also. If the pipes can be pushed out of line (as is usually
easier) this also aids in the installation of the union. Its only drawback
is that it has three gaps to leak instead of 2 and it is a little fatter.

Usually I have a bag of nipples from close to 5" (in 1/2" increments) so I
can get the union right where I need it.

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