kegging carbonated water (I know) but have some technical questions

[bracconiere]

this is probably a really stupid question
but how do I even tell if the dip tube has a problem?
is there a connection on the underside of the top of the keg?
Is it threaded on from underneath?

no stupid questions for a beginner!

yeah, the post will un screw and there is a little o-ring underneath the dip tube...it could be missing or damaged...

if it's a used soda keg all the o-rings should be replaced, or your seltzer will probably have a mild root beer flavor to it....

 

[DuncB]

So going back to the carbonation calculator.

35 psi and at 38 fahrenheit is going to be 4.8 vol.

Assuming you got the 4mm internal diameter eva barrier and have the tap 18 inches above the middle of the keg and want a US pint poured in 10 seconds the calculator estimates you need 14 foot of the beer line. This agrees with a previous posters figures.
An 18 second pour per pint needs 40 foot of line.

 

[IslandLizard]

It still comes out in random spurts like air pockets are getting in the lines.

Is the whole line solidly filled with water, or do you see gaps (pockets of gas) in it?

BTW, it's not air, it's CO2 ("gas").

 

[rtv900]

Thanks for the clarification on where that O ring will be, I will be removing that post as soon as I get home tonight
(long shot, but does anyone happen to know the size of that o ring? I work in a machine shop so we have about 9 million various o rings, I could easily grab a few, that way when I get home I can just replace it right away and not have to wait another day)

Yes I did get the 4mm ID, and it came in a 40' coil so I figured I may as well just try it all at first since I can easily cut it down later. Sounds like maybe I should cut it down. And yes I do see pockets of air, and it comes out of the tap as if there's pockets as well, constantly spurts the way one would expect while the lines are being filled, but it never goes away no matter how many pours I do.

edit: found another thread on here with O rings, it said #109, #111 and 417
I already replaced the huge one for the lid, and the ones on the outside of the posts, but not the one that isn't visible, so I'm guessing that would be the #109?

 

[bracconiere]

how did it go?

 

[rtv900]

I found an O ring similar but not quite close enough. The existing one was totally fried so I changed it anyway and will have to just order the right one. It was a little thinner and the ID seemed a tad big, but it actually sealed no worse than what I had.

 

[bracconiere]

I found an O ring similar but not quite close enough. The existing one was totally fried so I changed it anyway and will have to just order the right one. It was a little thinner and the ID seemed a tad big, but it actually sealed no worse than what I had.

well, you may just be drinking water, but the added carbonation attempt still makes it fun! don't leave me/us hangin if this gets solved or not

 

[IslandLizard]

I found an O ring similar but not quite close enough. The existing one was totally fried so I changed it anyway and will have to just order the right one. It was a little thinner and the ID seemed a tad big, but it actually sealed no worse than what I had.

Good plumbing stores have o-ring assortments, at least they used to. It's important to get the right size and thickness,* or you'll get leaks.
Once you know the right sizes, you can order them online too, in larger amounts. I haven't gone through that many of them over the years, including fixing other homebrewers' kegs.

Using keg lube is important, though!

* Original dip tube o-rings have a squarish profile, and look like as if 2 o-rings are stacked on top of each other. There's a narrow groove between the "top" and "bottom" section. Similar to airlock grommets for bucket lids, but much smaller.
They can be replaced by regular ones, having the correct thickness to make a positive seal.

 

[rtv900]

I got some 109's off mcmaster carr in packs of (100), also got the 111's. They might as well be free in packs of 100, costs more to ship them.
I did both dip tubes last night. I took off one of the air in connections but couldn't really tell where the hell the o ring even was. It kind of looked like it was up inside the bore but I didn't want to start digging around in there since I'm not really having air in issues AFAIK.
Bottom line, the tapping is WAY better now with those new O rings, I don't get the spurting anymore, it just flows consistent, so those fried O rings were definitely letting air come in the line
For reference, here is a pic of one of the ones I replaced.

 

[pvpeacock]

Yep, that will do it.

 

[IslandLizard]

For reference, here is a pic of one of the ones I replaced.

Definitely damaged/broken. That's one of those original "double deck o-rings," technically a grommet, due to the groove in the middle.*
That caused headspace CO2 going into the liquid line, and all the foaming. Now start cranking up that pressure until you get to the carbonation level you crave.

* Yes, they can be replaced with regular o-rings of suitable thickness, as you just did.