Corny keg O-ring oxygen permeability testing results

[SanPancho]

new kegland "low2" orings. (link is for keg "kit" ) Ball Lock Keg First Aid Kit | Replacement Parts & Seals Kit | KOMOS® | MoreBeer
picked some up recenty, havent had chance to brew, did new batch today so i'll get these suckers into the rotation and swap out the old silicone and even epmd ones.

- cue the bs, $hitposting and desmadre

 

[VikeMan]

Silicone is horrible from an O2 permeability standpoint. Was the "white" o-ring tested silicone? If so, it's impressive, but more or less expected. A comparison of the new matrerial with EPDM or Buna would be more interesting and perhaps more revealing.

 

[Unicorn_Platypus]

Does anyone have an idea of how these compare to EPDM?

I switched out all my O rings last year to EPDM on all my kegs

 

[day_trippr]

So far this is the best I can found wrt gas permeability of various compounds (seems pretty wide ranging though given the nature of PTFE and especially Polyimide). Anyway, EPDM is almost an order of magnitude more permeable than Buna-N, but at least an order of magnitude less permeable than Silicone...

Cheers!

 

[Unicorn_Platypus]

So far this is the best I can found wrt gas permeability of various compounds (seems pretty wide ranging though given the nature of PTFE and especially Polyimide). Anyway, EPDM is almost an order of magnitude more permeable than Buna-N, but at least an order of magnitude less permeable than Silicone...

View attachment 833328

Cheers!

Good find! Now where's O2 on that chart?

Assuming we can look at the other gases for a good sense?

My understanding is that Buna-n doesn't spring back as well as EPDM and therefore isn't quite as reliable of a seal. So it's probably the best happy medium.

Maybe go EPDM on dip tubes and posts /Buna-n on the keg lid

 

[Red over White]

Here's part numbers for Buna-N O rings for ball lock kegs.

McMaster Carr part #'s
Post 9452K23
Dip tube 90025K368
Lid 90025K551

These are so cheap, they're hard not to buy in bulk.

 

[Unicorn_Platypus]

Here's part numbers for Buna-N O rings for ball lock kegs.

McMaster Carr part #'s
Post 9452K23
Dip tube 90025K368
Lid 90025K551

These are so cheap, they're hard not to buy in bulk.

Nice! Do you have issues with getting a good seal on the posts with these?

 

[day_trippr]

Check out this article. It seems EPDM and Buna-N may have similar elasticity characteristics as the Durometer numbers are the same...

https://www.homebrewfinds.com/keg-o-ring-materials-selection-epdm-silicone-and-buna-n/
Cheers!

 

[Red over White]

Nice! Do you have issues with getting a good seal on the posts with these?

No sir. The lid seals are x profile and totally rawk!

 

[VikeMan]

Nice! Do you have issues with getting a good seal on the posts with these?

I don't have any issues getting a good seal with Buna-N for any of my keg o-rings.

 

[SBENCIV]

Here's part numbers for Buna-N O rings for ball lock kegs.

McMaster Carr part #'s
Post 9452K23
Dip tube 90025K368
Lid 90025K551

These are so cheap, they're hard not to buy in bulk.

Yup. This. I purchased these in bulk from Mcmaster years ago. A previous poster was correct that they will eventually flatten out, but they are so cheap that I just change them out once a year - before they get a chance to start flattening. With the exception of the lid o-ring. I can usually get a couple years out of those.

 

[ShaneB]

Here's part numbers for Buna-N O rings for ball lock kegs.

McMaster Carr part #'s
Post 9452K23
Dip tube 90025K368
Lid 90025K551

These are so cheap, they're hard not to buy in bulk.

Hey, do you have a part number for the universal popit o-ring?

The o-ring on these universal popits look much nicer the black ones on mine that get stuck. Universal Poppets | valuebrew.com

 

[Red over White]

Hey, do you have a part number for the universal popit o-ring?

The o-ring on these universal popits look much nicer the black ones on mine that get stuck. Universal Poppets | valuebrew.com

I don't have a part #. I was given a bunch from a brew buddy and have never investigated them.

 

[day_trippr]

This may be futile but I'm gonna post a heads-up warning here.

I have been noticing the outermost edge of some of my keg lid O-rings are cracking - badly - enough that the cracks may soon extend to where it matters. I have 16 five gallon kegs in service (along with a 3.5 and 3.5) and figured I better stock up on some O-rings to start swapping out the cracked ones.

There's a person on Amazon that has competitively priced cornelius keg O-ring sets ($1.80/set) that include lid, dip tube, and both ball lock and pin lock post O-rings. The seller has listings with differing quantities but the words "Stir-Plate" and "Home brewed with pride" appear in his placements to help identify them.

One of his listings is here, this one for 10 sets of O-rings. And if you look at the provided image you see an array of BLACK O-rings...

...which is a good start if you're hoping for Buna-N/Nitrile (same stuff/different names) - though I could not find any statement in the listing as to the actual rubber used. I relied on Amazon's good graces to cover my ample @ss on that.

Anyway, what actually arrived (three days late, but that's on AMZL) looked like this:

Alarms immediately went off - I definitely do NOT want silicone O-rings on my kegs - so I sent the seller a message via the AMZ portal asking what material was actually used in the set. His response was they were all SILICONE - and phrased in a way that made it seem this was a change from what he used to sell. So I explained why I'd be sending the package back immediately in favor of actual Buna-N O-rings.

After looking around on Amazon I found this listing for 10 sets which outright states Buna-N, so hopefully the next purchase will work out.

https://www.amazon.com/dp/B07Z5GQ77P

Be careful out there...

Cheers!

 

[Unicorn_Platypus]

This may be futile but I'm gonna post a heads-up warning here.

I have been noticing the outermost edge of some of my keg lid O-rings are cracking - badly - enough that the cracks may soon extend to where it matters. I have 16 five gallon kegs in service (along with a 3.5 and 3.5) and figured I better stock up on some O-rings to start swapping out the cracked ones.

There's a person on Amazon that has competitively priced cornelius keg O-ring sets ($1.80/set) that include lid, dip tube, and both ball lock and pin lock post O-rings. The seller has listings with differing quantities but the words "Stir-Plate" and "Home brewed with pride" appear in his placements to help identify them.

One of his listings is here, this one for 10 sets of O-rings. And if you look at the provided image you see an array of BLACK O-rings...

View attachment 842685

...which is a good start if you're hoping for Buna-N/Nitrile (same stuff/different names) - though I could not find any statement in the listing as to the actual rubber used. I relied on Amazon's good graces to cover my ample @ss on that.

Anyway, what actually arrived (three days late, but that's on AMZL) looked like this:

View attachment 842686

Alarms immediately went off - I definitely do NOT want silicone O-rings on my kegs - so I sent the seller a message via the AMZ portal asking what material was actually used in the set. His response was they were all SILICONE - and phrased in a way that made it seem this was a change from what he used to sell. So I explained why I'd be sending the package back immediately in favor of actual Buna-N O-rings.

After looking around on Amazon I found this listing for 10 sets which outright states Buna-N, so hopefully the next purchase will work out.

https://www.amazon.com/dp/B07Z5GQ77P

Be careful out there...

Cheers!

I wouldn't trust amazon for something as specific as this. I'd absolutely go through a more reputable vendor in this case

 

[hilljack13]

Some of the info here is confusing, but I am just getting starting with kegging. I have 4 kegland kegs with the white o-ring. Should I replace them? I have only used two of the kegs.

 

[day_trippr]

It's just a matter of vigilant oxidation avoidance from strike to glass
The oxygen permeability of Silicone rubber is much higher than that of Buna-N/Nitrile, but the cost is similar...

Cheers!

 

[mac_1103]

I wouldn't trust amazon for something as specific as this. I'd absolutely go through a more reputable vendor in this case

This was a pretty obvious substitution and a case where Prime free returns came in handy. A lot of "more reputable vendors" would do exactly the same thing but leave you on the hook for return shipping. What worries me are all the listings out there that don't say anything at all about what the product is made of. And plenty of those are from "more reputable vendors" too.

 

[day_trippr]

^Exactly - all of that^
And relying on Prime to cover vendor issues like this is part of the deal I pay them for every year.

Cheers!

 

[day_trippr]

fyi, today I received a full package of all-black O-rings - from the same vendor I dinged above.

Now I have to send him an email and see if I can revise my AMZ review

Cheers!

 

[day_trippr]

A follow-up to close this out: I updated my AMZ review to note what had transpired since and changed the rating from the 1 star to 5 - because he did come through in the end. And I offered to pay him if we could figure out how, but he thanked me for that and kindly refused, noting he was just happy I updated my review because most people do not.

Also, he explained he actually had switched to silicone because he felt they were more supple and sealed easier, and he felt that a keg pressurized with CO2 would keep the O2 out anyway. Had to gently direct him to the "partial pressure gas laws" to learn why he was wrong and that the only thing that would slow O2 molecules from passing right through would be higher O2 pressure inside the keg than outside.

I suggested he restructure his ads to provide the buyer the choice between silicone and Buna-N. At the least, buyers would know what they were buying whereas right now there's no indication of material either way.

Then, just as I was about to hit Send, I saw the seller's full name at the bottom of the AMZ messaging page, and realized I was "speaking" with a "Tom Hargrave" from Alabama, and there's a really good chance I bought my 6-tap stainless steel t-tower from him around 16 years ago! Ironically back then there was quite a lot of notoriety associated with that name and "Kegkits.com" (Google it and you'll end up back on HBT ) though I had nothing but good service from him. I asked - it should be interesting if he responds...

Cheers!

 

[day_trippr]

And it was indeed "that" Tom Hargrave.
So boggled to have crossed paths with him again after all these years.
The world grows smaller by the year

Cheers!

 

[Dog House Brew]

Bought all of my kegging stuff from him years ago. Still in use today actually!