[Shop-talk] CSST gas fittings

[Arvid]

Having recently put in 5 or 6 of these from Menards, both 1/2 and 3/4 
inch, and if my memory is any good, the incantation was:

Cut end as clean as possible. I did use a file on several of them to 
smooth out the jags and sharp edge that seemed inevitable when I cut it 
with a pipe cutter.

Strip yellow jacket to reveal 5 indentations.

Put nut on tubing.

Put metal ring on tubing.

Put o-ring on tubing.

Make sure gasket was still in the receiving side of the fitting.

Put together and tighten nut no more than 1/2 turn.

None of them leaked.

There was the o-ring plus a gasket that was in the base of the receiving 
side of the fitting to seal it. The gasket would be where the cut end of 
the tubing would butt up against to make a seal. Plus the o-ring to seal 
around the tubing.

Your description of the first one seems to only have the gasket on the 
receiving side and your description of the second one suggests it only 
had the o-ring. All of mine had both, which seems to make sense.

Arvid


On 2/22/2018 10:55 PM, Mark Miller wrote:
> So I just put in some flexible gas piping with CSST fittings. One 
> leaked.  I took it apart and replaced the fitting and all is OK but: 
> the new fitting is a very different design from the first. First 
> sealed the end of the tube to a surface on the connector, whole thing 
> held together by pressure against a ring you crimp into the 
> corrugations of the tube.  The replacement uses an o ring to seal it 
> all, so to the sides of the tube.  Which is newer? Which is preferred? 
> Or should I avoid this kind of plumbing altogether?  (personally I 
> think the o ring will give a better seal and isn't dependent on 
> cutting the tube cleanly).
>
>
> Thanks, o wisdom of the list!
>