O-Ring question - used cornies?

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robertbartsch

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Recently, I bought a bunch of used cornies and they needed help. The help included (a) a heat gun to remove many stickers, (b) a healthy scrubing with an abrasive sponge to remove outside sticky residue, and (c) replacing the o-rings on both the input and output valves.

The large o-rings on the tops appear OK, however.

Q. How do you know when to replace the large o-rings; these are soft and plyable now and the kegs hold pressure without leaking co2.

Thx..
 
They might retain the smell from soda if that was the most previous use. If you got them from another brewer and they still hold pressure then you are good. When I got mine from keg connection the o-rings were just replaced so I left them on. If in doubt, I'd just replace them.
 
The only thing I would be concerned about is that o-rings deteriorate over time. When I get "refurbished" kegs, I always do an inspection on the o-rings before use. I just roll the o-ring over a pen or pencil and use a magnifying glass to inspect for cracking, gouges, pitting or other deterioration. As mentioned before, you could just fail on the safe side and replace all of them.
 
Just as a routine I replace all o-rings on "new" old kegs. Then I don't have to think about it for a long time. Some of them looked like they were on the keg for 40 years. I've bought some "reconditioned" kegs that looked like they did not change anything.
 
You can get them in bulk from McMaster Carr. I have the part numbers somewhere. If they weren't specifically done when you bought them, I'd replace everything.

edit: Here they are.

(1) Dip Tube O-Rings
5/16" ID x 1/2"OD x 3/32" width
9452K172 BunaN #109
Pkg 100/$1.96

(2) Post O-Rings
7/16" ID x 5/8" OD x 3/32" width
9452K23 BunaN #111
Pkg 100/$2.15

(3) Lid O-Rings
3 1/2" ID x 4" OD x 1/4" width
9452K218 BunaN #417
Pkg 10/$12.69
 
I'm using ball-lock kegs. So the input and output o-rings are different sizes?

I have a large o-ring kit for repairs and when I changed these last night, I looked at these old ones closely; they appeared to be the same size.
 
I'm using ball-lock kegs. So the input and output o-rings are different sizes?

I have a large o-ring kit for repairs and when I changed these last night, I looked at these old ones closely; they appeared to be the same size.

They are the same size. I'm guessing you're confused between "dip tube" and "post" o-rings? Post rings go on the outside of the post, dip tube o-rings go around the diptube, between the diptube flare and the seat, which is accessible when you remove the post.
 
Do a visual inspection. Then...do a smell test. If you can smell/taste root beer, replace. I have over 10 kegs and I've only replaced the o-rings (including the ones for the lid) on half of them with no ill results. It seems that Root Beer is evil.......
 
I use a sniff and rub. There shouldn't be any smell and rubbing a damp finger on the ring shouldn't remove any rubber.
 
I hear a lot of folks commenting on smell....unless constantly submerged, this shouldn't cause an issue. Really, if there are no visible cracks or damage and it holds a seal, you're good. Use spray keglube to protect/extend their life. But then again, if you're paranoid, $15 is good insurance for ALL of your kegs.
 
I recycle the old O-rings without problems. Even the ones used for root beer can be cleaned up and re-used. I do give them a long soak in a bleach solution followed by another long soak in an Oxyclean solution followed with air drying. I cannot detect any residual odors after this treatment. I use Lubrifilm to keep them in good condition.
 
You can get them in bulk from McMaster Carr. I have the part numbers somewhere. If they weren't specifically done when you bought them, I'd replace everything.

edit: Here they are.

(1) Dip Tube O-Rings
5/16" ID x 1/2"OD x 3/32" width
9452K172 BunaN #109
Pkg 100/$1.96

(2) Post O-Rings
7/16" ID x 5/8" OD x 3/32" width
9452K23 BunaN #111
Pkg 100/$2.15

(3) Lid O-Rings
3 1/2" ID x 4" OD x 1/4" width
9452K218 BunaN #417
Pkg 10/$12.69

My hero! A $30 order ensures I pretty much never have to worry about rings again, heh.

As for the smell I just got my first two kegs today. I took them apart and soaked all but the rings in the tub with oxi. Cleaned the kegs up awesome but the rings smelled of Dr Pepper... like I could smell them sitting on my sink when I was standing over them. My understanding all the visible rings got changed so the smell was just coming from the 4 inner rings, wow.

Glad I ordered a couple ring sets with the kegs... though for what they cost me I could've gotten a couple hundred, heh.
 
CHIcompany sells O-ring sets with all 5 new gaskets for $1, for that price I can't talk myself out of it. Personally I'd still pay the $2.75 per set at my LHBS although probably not a large quantity.
 
I bought the silicone versions of all my orings, figuring they'd last even longer than the buna n, for just a bit more. I don't worry about it, just change them when they're needed.
 
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