McMaster Keg O-Ring List

[tre9er]

As far as using silicone o-rings on posts, I use them exclusively, got them for a steal, and I use pure mineral oil for lubricants. Haven't had to replace them in a few months so far.

 

[cwi]

As far as using silicone o-rings on posts, I use them exclusively, got them for a steal, and I use pure mineral oil for lubricants. Haven't had to replace them in a few months so far.

Your anecdote of successfully using silicone O rings for QD posts doesn't change the fact that they are not the appropriate choice for this 'dynamic' application. As for using only 'pure mineral oil' based lubes, I didn't state they weren't appropriate, especially for silicone. I also hope you realize 'pure mineral oil' is no different (possibly worse for EPDM and Neoprene) than the lubes I previously mentioned- Petrol-Gel, Lubri-Film, petrolatum, etc. They are all petroleum based products, including your 'pure mineral oil'. It's what puts the mineral in 'mineral oil'.

The point I was making, and still am, are the complications that arise from 'having' to use petroleum/mineral oil based lubes in some places, if you also encounter seals commonly used with commercial draft systems. These range from EPDM on Sankey keg valves (and therefore also couplers), or the very commonly used Neoprene washers for "Beer Nut" tailpiece fittings used on virtually all shanks in the US, even when only using Corny kegs. If the complication arises unnecessarily due to using silicone rubber in an inappropriate location, some would prefer to simplify their lives, especially if it works better as well.

Even if silicone post O rings were free, for some people the additional hassle of multiple lubricants, not to mention the decreased utility/performance versus Buna-N, would make it worth the price of buying Buna-N O rings. Since Buna-N O rings are both cheaper and better performing in Corny post applications, choosing to use silicone in this case does not seem like a wise choice, unless you get them for a true 'steal'.

There seems to be some kind of fascination with silicone, elevating its status to some kind of super material. It has its benefits in some applications, just as other materials have benefits over it in other applications. If silicone were a superior choice for Corny posts, the extra minimal cost would not have been a factor for soda makers. Instead, they chose Buna.

 

[tre9er]

Your anecdote of successfully using silicone O rings for QD posts doesn't change the fact that they are not the appropriate choice for this 'dynamic' application. As for using only 'pure mineral oil' based lubes, I didn't state they weren't appropriate, especially for silicone. I also hope you realize 'pure mineral oil' is no different (possibly worse for EPDM and Neoprene) than the lubes I previously mentioned- Petrol-Gel, Lubri-Film, petrolatum, etc. They are all petroleum based products, including your 'pure mineral oil'. It's what puts the mineral in 'mineral oil'.

The point I was making, and still am, are the complications that arise from 'having' to use petroleum/mineral oil based lubes in some places, if you also encounter seals commonly used with commercial draft systems. These range from EPDM on Sankey keg valves (and therefore also couplers), or the very commonly used Neoprene washers for "Beer Nut" tailpiece fittings used on virtually all shanks in the US, even when only using Corny kegs. If the complication arises unnecessarily due to using silicone rubber in an inappropriate location, some would prefer to simplify their lives, especially if it works better as well.

Even if silicone post O rings were free, for some people the additional hassle of multiple lubricants, not to mention the decreased utility/performance versus Buna-N, would make it worth the price of buying Buna-N O rings. Since Buna-N O rings are both cheaper and better performing in Corny post applications, choosing to use silicone in this case does not seem like a wise choice, unless you get them for a true 'steal'.

There seems to be some kind of fascination with silicone, elevating its status to some kind of super material. It has its benefits in some applications, just as other materials have benefits over it in other applications. If silicone were a superior choice for Corny posts, the extra minimal cost would not have been a factor for soda makers. Instead, they chose Buna.

No problem, and not refuting your points, simply giving my (albeit anecdotal) experience with the silicone o-rings I took a flier on. Your info is good, though, and perhaps next time I'll order the buna-n for $2 less per 100.

 

[cwi]

No problem, and not refuting your points, simply giving my (albeit anecdotal) experience with the silicone o-rings I took a flier on. Your info is good, though, and perhaps next time I'll order the buna-n for $2 less per 100.

No problem here either. I just have a habit pointing out when something is anecdotal vs. factual, especially if it appears to have been in response to factual info. Anecdotal evidence can be useful, especially when overly strict/complex/costly guidelines are proven, in practice, to be unnecessary. I don't see that being the case here, given that silicone is both more expensive (for most people), less durable, and introduces complexities.

I have not personally tried silicone post O rings, but even my Buna-N ones have taken a beating from R&Ring QDs. I wouldn't want even worse durability. The likely cause is that most posts, being industry cast offs, are in less than perfect shape, and result in less perfect insides on the QDs, especially in the 'guide portion'.

I have seen you post useful info in the past, so I didn't respond with my usual rebuttal for anecdotal evidence- my Uncle Billy's "lightnin' stopper stick" he carries around during storms. They are a simple device made from a sharpened 8' aluminum rod, and have served him well for many years.

The information I gathered and posted was not easy to find, and even more difficult to decipher. This was mainly due to the amount of mis/disinformation on the subject, especially lubricant and seal material compatibility. The use of silicone for being a poor choice for dynamic seals is (almost) universally agreed on.

 

[brettwasbtd]

So for those of us with pin locks and are having some gas leak issues (line gets pushed slightly one way or another and gas leaks) we are recommending the number #112 o-rings? An Buna-N is the better product?

 

[cwi]

So for those of us with pin locks and are having some gas leak issues (line gets pushed slightly one way or another and gas leaks) we are recommending the number #112 o-rings? An Buna-N is the better product?

If your Orings are beat up, new ones may help, along with lube.
If your lines are pushing things around, maybe try focusing equal effort there as well. Even with new Orings that work at first, you may not be aware of a leak until your newly filled tank is empty.

Are you fairly certain that's where the (only) leak is? As a leak detector, Star-san works OK, but diluted dish soap is usually a bit better. HVAC guys have some kind of super foaming stuff they use. Must have Carapils in it, or something.

I haven't looked at what size Oring is the latest rec for pin locks, so can't comment on that. For material, it's obvious what I would recommend.

Common CO2 line is fairly flexible, and shouldn't pose that much of a risk to pushing the QDs off axis enough to cause a leak. Those pin-lock QDs are tall, though. At least the ones I have are. One solution to the tall QD issue is to use the new SS pin-ball conversion posts for ~$15/pair, or cheaper sometimes. They will increase the value of your kegs by about the same amount, if you ever plan to sell them. Might be a decent solution if you have a mix of kegs.

 

[fifelee]

The use of silicone for being a poor choice for dynamic seals is (almost) universally agreed on.

I wouldn't really consider the post oring of a corny keg to be a dynamic seal. When orings are specified for dynamic seals they usually mean seals that spin 24/7 or slide repeatedly back and forth like in hydraulic cylinders. The occasional 1/2" that an oring slides in a keg post connector doesn't even register compared to most dynamic sealing. The vast majority of time a keg post oring is in a static situation. I won't worry at all about a split second of dynamic movement causing damage to a silicone keg post oring. But if one so chooses to spend time jamming a post connector on and off 24/7 for a few months then silicone is a bad idea.

 

[cwi]

I wouldn't really consider the post oring of a corny keg to be a dynamic seal. When orings are specified for dynamic seals they usually mean seals that spin 24/7 or slide repeatedly back and forth like in hydraulic cylinders. The occasional 1/2" that an oring slides in a keg post connector doesn't even register compared to most dynamic sealing. The vast majority of time a keg post oring is in a static situation. I won't worry at all about a split second of dynamic movement causing damage to a silicone keg post oring. But if one so chooses to spend time jamming a post connector on and off 24/7 for a few months then silicone is a bad idea.

Except that in those 'standard dynamic' applications you mention they are usually dealing with machined/polished surfaces, proper alignment, and in a grease bath of some sort. The corny post situation is dealing with crappy molded plastic that frequently has some non-trivial surface defects from being jammed onto 30 year old metal posts. Not to mention getting assaulted by the the locking mechanism, unless you use some king of jig to install your QDs.

Have you looked inside your QDs?
Have you looked at your O rings?
I have, and my post O-rings show significant wear, probably from a variety of things. I wouldn't want even less durability.

I don't see any of the properties of silicone being useful in this situation, and many disadvantages.
Can you offer any advantage for using silicone over Buna?

 

[fifelee]

Except that in those 'standard dynamic' applications you mention they are usually dealing with machined/polished surfaces, proper alignment, and in a grease bath of some sort. The corny post situation is dealing with crappy molded plastic that frequently has some non-trivial surface defects from being jammed onto 30 year old metal posts. Not to mention getting assaulted by the the locking mechanism, unless you use some king of jig to install your QDs.

Have you looked inside your QDs?
Have you looked at your O rings?
I have, and my post O-rings show significant wear, probably from a variety of things. I wouldn't want even less durability.

I don't see any of the properties of silicone being useful in this situation, and many disadvantages.
Can you offer any advantage for using silicone over Buna?

If you have ever dealt with hydraulic cylinders on farm equipment you know they are far from a fine polish surface (damn dirt and rocks). Again even with polish, alignment, and lube there is no comparison between a typical linear dynamic seal that may see 1000 two foot long cycles per day (at 1000 psi) to a keg post that sees 1/4" of travel once a month (at 15 psi).

That said, I agree the advantages of silicone aren't very strong and I to typically use buna. Silicone will form (seal) better around the defects you mention, but to me that isn't usually worth the cost because if defect are that bad I fix the defect. All I'm saying is the split second a silicone keg post oring sees dynamic movement will not cause damage on 99.9% of defects. If there is a defect so bad a 1/4" of travel will damage a silicone oring it will also damage a buna. In that case fix the defect. Your lube incompatibility of silicone is a much stronger argument then dynamic seal issues. Although a slightly swollen oring isn't always bad.

Personally the only real wear I have seen on post orings is on the kegs I got from a scrap yard. I assume those orings had years of caked on soda that caused the damage. New oring I have installed (silicone or buna) hold up just fine. Plus I think most hombrewers like me change the oring every few keg uses. If you want to keep the same oring for 10 years then I agree buna all the way. But for most homebrewers I say if you want silicone don't worry a bit about an occasional 1/4" of dynamic travel and they may even seal a bit better on an imperfect QD surface. Actually, cwi, if your QD's are really beat up, you may want to try silicone orings and just change them often or maybe get some new QDs.

Homebrewers if silicone makes you feel better buy silicone. They likely will seal slightly better on defects plus they come in a very attractive orange color. If you see damage change them. If you are worried about cost buy buna. If you see damage change them. If your QDs are so beat up they damage any oring, then get a new QD. Now can we all just relax and have a beer.

 

[fifelee]

When I make my next McMaster-Carr order, I will try these: Silicone Oring 10mm(ID)x3mm

Has anyone used the above silicone orings for pin-lock's?

I did finally try the 10mm (ID) x 3mm oring on my pin locks. Yes cwi I used Buna. I had to stretch them a bit more then I like, but they seem to seal very well. When placing the QD you can feel how it is a tighter fit than the #111 or #112 orings. I'll be using them from now on and will report any issues. Might even order some silicone to upset cwi.

 

[cwi]

If you have ever dealt with hydraulic cylinders on farm equipment you know they are far from a fine polish surface (damn dirt and rocks). Again even with polish, alignment, and lube there is no comparison between a typical linear dynamic seal that may see 1000 two foot long cycles per day (at 1000 psi) to a keg post that sees 1/4" of travel once a month (at 15 psi).

The hyd cylinders I've seen don't usually use O rings on the exposed surface. They also usually leak like sieves. Maybe they should follow your advice and use silicone wipers and seals? Doubtful. The comparison of QDs to hyd cylinders or rotating seals is not valid.

That said, I agree the advantages of silicone aren't very strong and I to typically use buna.

Had you stopped there, I probably would have let all this slide.

Silicone will form (seal) better around the defects you mention, but to me that isn't usually worth the cost because if defect are that bad I fix the defect.

If the defect is bad enough to make a Buna O ring leak, it would be bad enough to shred a silicone one. Durability wins out for this type of fitting.

All I'm saying is the split second a silicone keg post oring sees dynamic movement will not cause damage on 99.9% of defects.

I don't see how the time factor (split second) is relevant, and faster is actually worse.

If there is a defect so bad a 1/4" of travel will damage a silicone oring it will also damage a buna.

If the defect is so small that it will not damage a silicone O ring, a Buna O ring will also seal just as well. See, I can do it, too.

Your lube incompatibility of silicone is a much stronger argument then dynamic seal issues. Although a slightly swollen oring isn't always bad.

Except that silicone swollen/degraded from improper lube also has drastically reduced integrity/durometer.

Personally the only real wear I have seen on post orings is on the kegs I got from a scrap yard. I assume those orings had years of caked on soda that caused the damage. New oring I have installed (silicone or buna) hold up just fine. Plus I think most hombrewers like me change the oring every few keg uses. If you want to keep the same oring for 10 years then I agree buna all the way. But for most homebrewers I say if you want silicone don't worry a bit about an occasional 1/4" of dynamic travel and they may even seal a bit better on an imperfect QD surface.

You have a talent for hyperbole in making your case. Split seconds, 1/4", 10 years, etc. I just don't see it making the case for silicone. Maybe if you included direction for replacing them 20-30 times as often, taking 1000 times more care when R&Ring QDs, using new QDs every time you switch kegs, etc., then your case for silicone would be a bit stronger.

Actually, cwi, if your QD's are really beat up, you may want to try silicone orings and just change them often or maybe get some new QDs.

They will just get beat up again from the posts, and from reaching around/over things when trying to install the QDs. Also, it's more than 1/4" of travel, and the O rings do more than just seal, they also provide some support against deflection, so the correct durometer is important there as well.

I found the solution to QDs, poppets, relief valves, and all Corny issues- it's called Sankey.

Homebrewers if silicone makes you feel better buy silicone. They likely will seal slightly better on defects plus they come in a very attractive orange color. If you see damage change them. If you are worried about cost buy buna. If you see damage change them. If your QDs are so beat up they damage any oring, then get a new QD. Now can we all just relax and have a beer.

Yes, if silicone makes you feel better, buy it. Just don't go around squawking that it does anything more than impress the ladies.

As for when it's time to change out a silicone O ring, the best indicator is your empty CO2 tank.

 

[fifelee]

cwi, when you wrote "Not to mention getting assaulted by the locking mechanism", I couldn't stop laughing as you take minor issues to such an absurd level. I thought it would be fun to mess with you, but I have better things to do then continue this silly discussion. You win. Although I have a mechanical engineering degree and spent eight years specifying orings and oring lubricants you have convinced me a seal that doesn't move 99.9999% of the time is dynamic and a minuscule amount of travel over normal minor defects will shred silicone orings. All homebrewers who use silicone orings should be subject to your public mocking.

 

[jchawk]

This thread has been one of the most entertaining ever! Thanks all!!!

 

[mmurray]

I did finally try the 10mm (ID) x 3mm oring on my pin locks. Yes cwi I used Buna. I did have to stretch them a bit more then I like, but they seem to seal very well. When placing the QD you can feel how it is a tighter fit than the #111 or #112 orings. I'll be using them from now on and will report any issues. Might even order some silicone to upset cwi.

Thanks for the info... just for safe measure, these are the ones you used? http://www.mcmaster.com/#catalog/119/3478/=m6ci0r

It's nice to have a definitive answer on Pin-Lock O-Rings... I have not used my pin lock kegs in 2 years since I dumped 1/2 a keg into the bottom of my fridge!

 

[mmurray]

I'd also like to add an O-Ring to the list. Many of us use the Polysulfone Disconnects by CPC.

The O-rings are thin and don't generally hold up well, so for those of you who need to replace them here is that O-Ring from McMaster-Carr.
Dash - 016
ID: 5/8"
OD: 3/4"

http://www.mcmaster.com/#o-rings/=m6cnec

Hope this helps.

 

[fifelee]

Thanks for the info... just for safe measure, these are the ones you used? http://www.mcmaster.com/#catalog/119/3478/=m6ci0r

It's nice to have a definitive answer on Pin-Lock O-Rings... I have not used my pin lock kegs in 2 years since I dumped 1/2 a keg into the bottom of my fridge!

I ordered from Amazon, but the 9262k263 (3mm Wide x 10mm ID) from McMaster in your link above is what I would use.

 

[helibrewer]

Here is a poppet valve solution:
http://www.kegkits.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=PVALVE

They are universal valves with replaceable o-rings.

 

[SP0tter]

Anyone know a Canadian source (or 'established customer')?
From McMaster-Carr, after I ordered some.:-

"Due to the complexity of U.S. export regulations, McMaster-Carr accepts international orders only from our established customers. This decision also applies to orders shipping within the United States, because it is based on the final destination of the items. We cannot accept this order or future orders."​

I see this was adressed in another thread:-
https://www.homebrewtalk.com/f35/canadian-corney-keg-o-ring-suppliers-108061/

 

[Bablitz]

SP0tter: Anyone know a Canadian source (or 'established customer')?

From McMaster-Carr, after I ordered some.:-

"Due to the complexity of U.S. export regulations, McMaster-Carr accepts international orders only from our established customers. This decision also applies to orders shipping within the United States, because it is based on the final destination of the items. We cannot accept this order or future orders."​

I received this same reply today, sounds like a crock to me but that is how they roll...

Ordered everything I needed, including the quad rings from:

http://www.oringsandmore.com/

And they take Pay-Pal!

 

[SP0tter]

Thanks.
For the posts, external, AS568A, Dash 111 :-
http://www.oringsandmore.com/silicone-o-rings-size-111-price-for-50-pcs/
I ordered a package of the silicon ones.
I shall let you all know what happens.
...
...
...
Package of 50 silicon # 111S 'O' rings arrived yesterday (14th May).
$2.20 US + $4 US shipping.

 

[SP0tter]

Package, from oringsandmore, as described earlier, arrived safely.
I have replaced the post external 'O' rings on all four kegs.
No problems since!

 

[hennesse]

The dip tube o-rings that came on the kegs I've bought from soda distributors have a square cross-section instead of round.
McMaster# 4061T155

Same for the plastic ball-lock disconnects.
McMaster# 4061T118

I've never had a leak due to o-rings. But I have had poppets leak on kegs that are waiting their turn in my non-kegerator refrigerator - with nothing connected to them.

I drilled an 5/8" hole in the bottom of a film canister (remember when cameras used film?). Place over the keg post so it sits on top of the o-ring, and add a little water - a leaky poppet will be readily apparent.

 

[butterpants]

Here is a poppet valve solution:
http://www.kegkits.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=PVALVE

They are universal valves with replaceable o-rings.

Hopefully this product lives up to the hype. I bought enough to retrofit all my kegs.

 

[MercMan]

I tried the universal poppet valves. They work OK but not as well as the originals.

 

[AznDrgn]

I just read through all the threads here and I didn't see any mention to replacement o-rings for the pressure relief valve. I've google'd and I see a lot of PRV's advertised as having replaceable o-rings but nobody seems to sell them or even list a size. Does anyone have a size or source for that o-ring? I've attached a picture of the type of PRV that I have, I don't know if there are any different ones.

 

[habutti]

Can someone please tell me what o-ring I need to purchase from McMaster to use on poppets for a pin-lock keg?

 

[butterpants]

Here is a poppet valve solution:
http://www.kegkits.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=PVALVE

They are universal valves with replaceable o-rings.

Been using these a month now.... retrofitted 5 kegs. The poppets seem to fit well. Springs included are quite stiff amd long. They fit but you actually have to press on your posts during installation. The new poppets/springs limit flow significantly compared to the older style..... for example if I hooked up a keg with only some star san in it just looking for am O2 purge, with the old poppets my gas regulator would scream and the keg was filled in a few seconds, utilizing the universal poppets the flow is much more regulated..... same situation now takes 30 seconds and no feedback from regulator. It's also much harder now to press on ball lock fittings to top of the keg.... like crazy hard. Might switch to a metal type fitting instead of plastic.

 

[DM3MD157]

Does anyone have a Amazon link to Buna o-ring for posts? The previous post is for silicone, not sure if anyone knows the Buna counterpart.

 

[adamant]

Homebrewfinds.com did a post with links recently.

 

[atoughram]

Does anyone have a Amazon link to Buna o-ring for posts? The previous post is for silicone, not sure if anyone knows the Buna counterpart.

http://www.amazon.com/dp/B0052AU0HQ/?tag=skimlinks_replacement-20

The dash size for posts is 111 I believe.