John Guest PTC connector cracked. How tight is tight enough? Opinions solicited.

[balrog]

I have not completely overhauled everything I have to PTC.
I end up switching the handful of PTC connectors I have around, whether to feed gas, transfer beer, whatever.

Did I crank one one of the MFL joints too tightly? It cracked and leaks, gas or liquid.

Luckily I do have a couple spares.

 

[Spundit]

Yes, you probably torqued it a bit too much although it is possible it was defective.

I use the Duotight fittings (similar design) and crank to just past finger tight. I haven't had one crack or leak yet but that may just be luck.

 

[pigroaster]

Finger tight and a 1/4 turn more with a wrench going slowly. Some people are worried about their tubing coming out and install keepers so ring stays out. Just make sure the tubing is home (bottom of slide in area)

 

[day_trippr]

I have a metric crapton of PTC connectors in service having switched every beer, gas and rinser lines in a keezer and three fridges to EVABarrier tubing back in 2019. Nearly all are John Guest, but I do have some Duotights and DMfit parts as well. I would hand tighten then do a dunk test and wrench-tighten a bit at a time until any leak stopped. The only one I managed to crack was a Duotight 1/4" FFL to 8mm tubing. It was totally obvious at the instant it happened and it was totally my fault, got distracted and forgot where I was with it.

I'm a huge fan of dunk-testing everything possible. Over three keezer builds I've found all kinds of leaks that way...

Cheers!

 

[balrog]

I Figured you'd chime in, @day_trippr having converted everything, likely including swallow-cam, to PTC

 

[Bobby_M]

Best practices... light coat of keg lube on the threads and flare point of the opposing fitting. Hand tight, check for leaks (99% chance of none). 1/8th turn, check for leaks.