Sealing John guest disconnect

Secla · Post by **Secla** » Mon Nov 30, 2015 3:06 pm

Just got a co2 bottle and reg. also picked up a push fit John guest fitting for the reg output !
Seems it's leaking a little. Should I seal the threads with regular Ptfe tape or is there something specific I should be using ?

DeadFall · Post by **DeadFall** » Mon Nov 30, 2015 5:12 pm

Mine doesn't need sealing. I spray it with star-san to check for leaks. If you over or under tighten it, it will leak. Use your hand to tighten, not tools.

Secla · Post by **Secla** » Mon Nov 30, 2015 5:55 pm

Yup that's what I've experienced with other fittings, all my other jg fittings have a rubber washer built in, this one doesn't

Fil · Post by **Fil** » Mon Nov 30, 2015 7:11 pm

plumbers ptfe will be fine, iirc gas fitters sealing tape is the same thing only a bit thicker, so just use another wrap or 2 ...

Secla · Post by **Secla** » Mon Nov 30, 2015 7:30 pm

Not really obvious in the picture but the smaller one is the new fitting

Wonkydonkey · Post by **Wonkydonkey** » Mon Nov 30, 2015 11:28 pm

They look like 2 different size fittings, if the old one is the top fitting in the pic.

Secla · Post by **Secla** » Mon Nov 30, 2015 11:33 pm

they are 2 different size fittings but both john guest push fit.
As i said all the other john guest fittings ive had have a rubber seal in them, this one doesnt

Wonkydonkey · Post by **Wonkydonkey** » Tue Dec 01, 2015 12:04 am

Ahh, I reread your first post, still not really sure, what it is you want to know, but you may get your answer here.

If the fitting does not have a rubber washer in the bottom of the thread, then a bit of Ptfe tape will do the job, and that really uesd mostly on the cornie disconect sides
If it has a rubber washer in the bottom of the thread, then it's unlikely that ptpe will do the job that well. There was a few peeps having a problem, and that was the female thread on the JG was a bit longer than the male thread so it was not able to meet the bottom. Soto fix it, the easy way was to sand about 2mm off the JG.

And I say this, because the top fitting in your pic looks like what would go on a reg and the bottom looks like it goes on a disconect

Anyway, your get there

Secla · Post by **Secla** » Tue Dec 01, 2015 12:09 am

you may have hit the nail on the head, when I screw it all the way onto the regulator nipple it butts all the way up to the end and im not convinced its fully engaged.
Ive popped a bit of ptfe on and will test it tomorrow, If that doesn't work i`l try sanding a bit off as you say

rpt · Post by **rpt** » Tue Dec 01, 2015 1:57 pm

Parallel threads seal with a washer. Taper threads need PTFE tape to seal. If the fitting has a washer then it is parallel and you need the washer to engage.

Wonkydonkey · Post by **Wonkydonkey** » Tue Dec 01, 2015 3:25 pm

rpt wrote:Parallel threads seal with a washer. Taper threads need PTFE tape to seal. If the fitting has a washer then it is parallel and you need the washer to engage.

+1

Your prob, better off just a bit of sandpaper on the floor, and hold the fitting in ya hand and go round in circles and occasionally turn the fitting a 1/4 turn. This way you get a more even sanding. But others have held it in a vice and a small hacksaw has done the job. It depends on the tools you have.

Anyways like I said b4, your get there, now you know

Secla · Post by **Secla** » Tue Dec 01, 2015 5:17 pm

Well seems ptfe did the truck burials idem towable a leak around the prv thread
Emailed where I bought it to see if they have a solution as I have tightened it as much as I can and it has a rubber seating washer so should need ptfe

Secla · Post by **Secla** » Tue Dec 01, 2015 5:43 pm

Major issues with this reg
Thread sealed but prv seams to be leaking itself, adjust the pressure nothing happens then all of a sudden it spikes and the prv bursts open
Used about half a bottle of gas pissing about trying to get it working properly

borischarlton · Post by **borischarlton** » Tue Dec 01, 2015 5:55 pm

With some regulators it would seem there is to much material on the JG fitting. You can get round it by adding a kevlar washer. I have some here if you need me to send one.

Secla · Post by **Secla** » Tue Dec 01, 2015 6:41 pm

I seem to have got it sealed now, but set at 15 psi you can hear the prv is open and hissing gas out
Not sure at what psi it should open but pretty sure it should veal it higher than that

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