ran a search and came up empty. Does anyone have a source for the o-ring which is INSIDE the gas and liquid connectors (Ball Lock) … I took one apart to clean it and lost the little bugger >:( down the drain… It is so light that the sink trap didn’t save me… thank you and cheers!! …
The “#” is the standard number for that specific size O-ring. You can search on that or get some from your local hardware store.
Dip Tube O-Rings
5/16" ID x 1/2"OD x 3/32" width
#109
Post O-Rings
7/16" ID x 5/8" OD x 3/32" width
#111
Lid O-Rings
3 1/2" ID x 4" OD x 1/4" width
#417
I haven’t found a bulk source for the flat internal gasket, but here’s a link to buy them one at a time:
http://www.williamsbrewing.com/KEG-CONNECTOR-INNER-GASKET-P2296C110.aspx
Post o-ring - #9452k23
Dip tube o-ring- #9452k172
Lid o-ring- #9452k218
Internal o-rings for the connector, not the post or dip tube or lid o-rings.
Sorry, I don’t have a source. If you can measure the dimensions accurately enough (or find them somewhere) you might find something at mcmaster.
They are called becker disconnect cap washers… Most places seem to have them for less than 50c each, both my local homebrew stores do, as well as Northern Brewer, Williams, and Chi Company… I know this because I lost one down my deck drain, then I had another one that I messed up somehow when I put the connector back together so it stopped sealing, then the last good one I had I put in my pocket to go and check around at the hardware stores, and when I got home it was gone…
here ya go:
Dash Number 013
O-Ring Cross Section Shape Square
Width 1/16"
Actual Width .070"
Inside Diameter 7/16"
Actual Inside Diameter .426"
Outside Diameter 9/16"
Actual Outside Diameter .566"
Material Buna-N
Awesome. Now to put them all in one post for historical purposes, making it easier for me to find next time. 
Post o-ring - #9452k23
Dip tube o-ring- #9452k172
Lid o-ring- #9452k218
Ball lock connector interior o-ring - #4061T118
Can we get a “FAQ” section?
thanks everyone… you are all the reason this forum rocks!!! I raise a glass to all the respondents…and everyone else on this forum… ;D
I was thinking about this a while back. It doesn’t seem like these o-rings need replacing very often. How do you know when they need replaced except for losing them?
I wouldn’t replace them unless they were obviously damaged or there was a problem with leaks. Cracked, torn, etc. I’ve never had that happen though, I’ve just lost a couple.
Ah, word to that.