John Guest fittings

[Torshon]

Merry Christmas and a happy new year to all the homebrew community!

i have a question i would like to ask, i was lucky enough that santa bought me a boel itap for christmas (i must be a very good boy)
as i want to fill bottles straight from my fermzilla im thinking i will need to use 2 soda stram co2 bottles (1 for the fermzilla to keep the pressure up and 1 for the boel to purge etc)
so apart from c02 regulators and beer line was looking at jg fittings and then saw these:

can someone tell me what the difference is and why the threaded fitting against the barbed fitting
im new to co2 so am learning , have been successfully bottling carbed beer to bottle by depressurising and filling at low temps but want to go to oxygen free transfer to bottle as much as is possible

cheers all

 

[Rodcx500z]

Grey is gas in black is beer out

this setup is for the one's on the feft

 

[AnimatedGIF]

The threaded disconnects are for attaching a John Guest pushfit, in to which you push the 3/8 (or 5/16) tubing. With barbs, you attach the tube over the barb and use a clamp/jubilee clip. Anecdotally, the former seems to be the preferred/most reliable way to attach.
Regarding CO2, you wouldn't need two cylinders I wouldn't have thought, though I could be wrong as I am not very familiar with the iTap beyond having a reasonable idea of thatbit is used for.

 

[Eskimo John]

I use the threaded type and the screw on JG fittings. They are very reliable and quick to dismantle when you want to clean lines etc.
In the photos above you can see a grey proud collar next to the beer /gas line. Just pushed these in and the line will tug free.

 

[Corbières]

I split the gas supply at the bottle - one line to the keg and the other to the iTap

 

[Torshon]

Wow thanks for the response guys.
I now understand better, and thanks for the split on the gas line i think that'll do it