Teflon on CO2 outpost

[Kickass]

I’ve read a lot online advising against using Teflon on a CO2 outpost.

I bought a used tapright regulator that didn’t have an out post. After some research it appeared I needed a 1/4 inch MPT fitting. I bought one and installed it (admittedly, I didn’t have any pipe dope). I did a soap bubble check and it failed miserably. I then added Teflon to see if that would seal it, and it did. Are there any concerns with this? Numerous image searches and past experience turns up a rough 50/50 result of outposts having Teflon on them.

 

[day_trippr]

I expect that is a brass 1/4" male straight pipe thread to 1/4" male flare adapter, and using tape - or sealant - on the pipe thread to regulator side where you show it is actually proper. It's the flare side of that brass fitting, where you have the PTC fitting screwed, where tape is neither needed nor desired, as flare fitting does not seal via its threads, it seals by a face-to-face connection.

So you're good there, but I'm seeing something suspicious here. Sure looks like bubbles...

Cheers!

 

[Broken Crow]

The genuine shutoff with integrated check valve is available.. I just linked to it in another thread: https://www.taprite.com/6600ca-6600ca
I know 95% duotight users have no problem and I will still recommend them to others, but I had a few failures, one being a faulty part, but the others were probably my own incompetence, and it's hard for me to fully trust them or my own ability to use them now.

 

[lumpher]

I expect that is a brass 1/4" male straight pipe thread to 1/4" male flare adapter, and using tape - or sealant - on the pipe thread to regulator side where you show it is actually proper. It's the flare side of that brass fitting, where you have the PTC fitting screwed, where tape is neither needed nor desired, as flare fitting does not seal via its threads, it seals by a face-to-face connection.

So you're good there, but I'm seeing something suspicious here. Sure looks like bubbles...

View attachment 842488


Cheers!

My eyes went right to that, too. Looks like a very small leak, still.

 

[whoaru99]

One thing to confirm would be that flare angles match.

 

[day_trippr]

Also the penetration depth matters. If the faces don't meet they cannot seal...

Cheers!

 

[hotbeer]

I think the reason they don't want you to use teflon tape is that it shreds as you tighten the fittings together and some of those shreds might come off and get into the regulator and do what any other dirt or foreign objects would do in there.

Pipe dope is less likely to be a issue. Probably why there are 50/50 mixed reviews/opinions on why it's really okay or not. A certain percentage of the nays had a bad experience.

 

[hotbeer]

I expect that is a brass 1/4" male straight pipe thread to 1/4" male flare adapter, and using tape - or sealant - on the pipe thread to regulator side where you show it is actually proper. It's the flare side of that brass fitting, where you have the PTC fitting screwed, where tape is neither needed nor desired, as flare fitting does not seal via its threads, it seals by a face-to-face connection.

So you're good there, but I'm seeing something suspicious here. Sure looks like bubbles...

View attachment 842488


Cheers!

Soapy water sometimes or actually many times, gets brushed on with lots of tiny bubbles already in it. The clue for a leak is if any of those bubbles get bigger.

 

[whoaru99]

There's technique to using thread tape or pipe dope.

 

[odie]

what are the threads? NPT? straight? is there a tefalon disc or seal already inside?

 

[whoaru99]

Depends which ones.

The brass MFL to DuoTite adapter would be the metal flare cone to plastic flare seat.

My regulator connections are 1/4" female pipe with taped couplers and taped 1/4" MFL adapters.

Came assembled that way, using tape, from the supplier.

 

[sibelman]

On the NPT side, Teflon™ tape seems totally normal. Even Taprite apparently uses it.

On the flare side, not so much. The seal between metal male-female flare joints is ensured by these washers.

the penetration depth

Given the small bubbles in the second photo, it could be that the fitting OP added isn't long enough on the output side to fully seal with the Duotight. Beside replacing the newly added fitting, what can be done there?

 

[whoaru99]

Beside replacing the newly added fitting, what can be done there?

Since that should be a flare to flare seal, one could try the same washers used in the steel to steel flare joints. That'd give a little more leeway for a short fitting or deep hole.

 

[day_trippr]

I was about to suggest the same: try a nylon fish-eye gasket typically used inside swivel nut/barb connectors.
But be careful not to overtighten and blow out the back of the PTC fitting as the nylon will not deform as readily as the fitting plastic does.

If a dial caliper is available some geometry investigation could be performed...

Cheers!

 

[Kickass]

Thanks all! I appreciate the feedback. The little bubbles between the outlet and duotight were from being a little to ginger screwing the duotight on. Plastic on metal makes me timid. After another 1/4 turn they stopped completely. I’ll double check all the fittings again when I complete the buildout.