correct swivel nut / barbed post assembly

[gromfy]

I feel dumb asking this, but I want to make sure to get it right. I'm in the middle of a motorized carbonator install for a home seltzer system, and the fittings kit I ordered came with a set of swivel nut / barbed post fittings.

I had assumed that the correct assembly would be to pass the hose through the nut, then the plastic disc, then the barb, pulling the nut toward the front to seal everything up. Basically how quick-fit 1/4" icemaker line fitings work. So, I tried this:

That didn't work, since the tubing on the barb is too thick to pass through the nut when I went to tighten everything up.

Then it occurred to me that it probably was a matter of just passing the barb through the nut, putting the plastic piece on the outside (tube side) like a washer, and then attaching the hose to the barb (seating it as close to the nut as possible). Like this:

That goes tube > plastic washer > barb (which passes from inside the nut). Is that the correct approach? It seems solid, but, before I test it, just wanted to check. Thanks!

 

[dutchoven]

Can't quite tell from the pics, but that black plastic piece may be a flare fitting washer. If so, put it between the flare fitting and the barb, then tighten down.

 

[thargrav]

dutchoven is correct - the flare washer goes in front and is caught between the two fittings to make a seal.

 

[gromfy]

Thanks for the quick responses. I guess that means like so:

I would assume the wider/flared side sits against the tubing and the narrower end sits against the nut. Thanks again!

 

[rekoob]

nope.
the black washer goes all the way to the right.

 

[GilaMinumBeer]

However, often times the black washer is un-necessary with some brand disconnects since they often have integral washers.

 

[rekoob]

I agree that a lot of times they will seal without them. however, i had a leak in my system and lost 10lbs of co2 from one leaking after a few kegs of use. i guess the movement of the hose or something. i have sense installed washers at each connection. maybe overkill in my case but i havent had another ssue. and what are they ten cents or are they even cheaper then that? i can't remember, not an issue really.

 

[P-J]

If it is a metal to metal connection, use the washer.! If it is to connect with a soda keg disconnect it is not needed. That is the only one I know of that has a built in washer - The flare QD on a corny keg.

Everything else - use the washer to eliminate the metal to metal seal connection.

IMHO

 

[gromfy]

Ah. It's a washer! That all makes sense now. I never would have expected a plastic washer to seal up a metal-to-metal connection (which is what I have throughout).

All makes sense now. Thanks everyone.