[Shop-talk] CSST gas fittings

[Arvid]

Here is the "replacement parts kit" for the ones that I used ... 
https://www.menards.com/main/plumbing/rough-plumbing/pipe-tubing-hoses-fittings-accessories/shop-all-pipe-fittings/flexible-gas-pipe-fittings-accessories/pro-flex-csst-replacement-parts/pfap-1210/p-1444445270709-c-9529.htm?tid=-4959026828721381472&ipos=4 
... and the instructions ... 
https://hw.menardc.com/main/items/media/TRUFL001/Install_Instruct/PRO-FLEX_2009_INS_MAN_15.pdf.

There is a silicone o-ring and a high temperature sealing gasket. I had 
assumed that the end of the tubing rested against the high temperature 
sealing gasket.


On 2/24/2018 12:35 AM, Mark Miller wrote:
> Sorry, I was unclear.  I bought some that had a heavy metal ring, 
> placed on the first corrugation, that held the nut on.  With that 
> design the cut end of the tube butted against a deformable gasket on 
> the 'fixed' end of the fitting.  Instruction then said to torque the 
> nut down fairly hard (60 ft-pounds?).  The second set sound like the 
> one you discussed: split ring to hold the nut on, 5 corrugations 
> back.  Metal ring next, then the o ring.  The cut end of the pipe was 
> not the sealing surface: it is the o ring against the metal ring and 
> the end of the fixed fitting half.  I am guessing that design replaced 
> the first one.
>
> Regards,
>
> Mark Miller
> markmiller at threeboysfarm.com
>
> On 2/23/2018 5:27 AM, Arvid wrote:
>> 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!
>>>
>>
>>
>
>
>