McMaster Keg O-Ring List

[fifelee]

In a former life I spent eight years engineering which often required specifying orings. I also recently acquired 10 pin locks so I thought I would jump in. The oring bible is the parker o-ring handbook: http://www.parker.com/literature/ORD 5700 Parker_O-Ring_Handbook.pdf

2-111 orings have an ID of .424 and an OD .630
This is for a gland of .463 and a bore of .625

2-112 orings have an ID of .487 and an OD of .693
This is for a gland of .525 and a bore of .687

My measuring of pin lock posts and connectors shows a gland of .485 and a bore of .655. As you can see this is between the 2-111 and the 2-112.

2-xxx are the standard orings available most anywhere.
There is another series of 5-xxx orings that are custom sizes.

Looking on the custom chart (pg 237 of the attached pdf) there is a oring that looks perfect. 5-615 has an ID of .469 and an OD .675

Now these custom oring often require a large order with expensive tooling setup charges, but sometimes one can get luck and a dealer has them on the shelf. I’ll call around to a few places I know but it will likely be just as cheap to order the proper oring from places like CHI.

http://www.chicompany.net/index.php?main_page=product_info&cPath=376_1_3_6&products_id=2547

Finally if I was going to use one of the standard orings I would use the 2-112. Because it is larger it has more material to squeeze into the gland which would be more likely to seal.

 

[Veedo]

fifelee, sweet we now have an o ring guy! i think we have a couple orings that came on used kegs that were actually bigger than the sizes i listed. work good. the replacement ones that shipped with my used kegs, and the smaller ones in this thread, NFG.

 

[raouliii]

....
2-111 orings have an ID of .424 and an OD .630
This is for a gland of .463 and a bore of .625

2-112 orings have an ID of .487 and an OD of .693
This is for a gland of .525 and a bore of .687

My measuring of pin lock posts and connectors shows a gland of .485 and a bore of .655. As you can see this is between the 2-111 and the 2-112.
.....

I was looking at Mcmaster-Carr metric o-ring sizes and this one appears to be in between the #111 & #112.

2.5mm x 12mm : ID of 0.472 / OD of 0.669 / thickness of 0.098

In Silicone: 2.5mmx12mm

Could these be a better option for pinlock kegs?

 

[fifelee]

I was looking at Mcmaster-Carr metric o-ring sizes and this one appears to be in between the #111 & #112.

2.5mm x 17mm : ID of 0.472 / OD of 0.669 / thickness of 0.098

In Silicone: 2.5mmx17mm

Could these be a better option for pinlock kegs?

I think the oring you are looking at is the 12mm (.472 ID) x 2.5mm (.098 W). This looks close but the width is a concern. I did some calculations. Normally static oring seals are set up to compress about 18%. From my measuring the correct pin lock oring setup has a 16% compression. A bit lower then standard but still okay. The metric oring you mention has a reduced width and the compress ends up being about 12%. What I think could work is go to a 3mm oring with a reduced ID. The 10mm (ID) x 3mm (W) will have to be stretched over the post, but this would also reduce the width to be close to the standard. This results in about a 20% compression. Just an idea I may get around to trying.

FYI the 2-111 only has a 11% compression. That is why some people have had issues with leaks.

 

[raouliii]

I think the oring you are looking at is the 12mm (.472 ID) x 2.5mm (.098 W)....

thanks, I fixed the link

..... This looks close but the width is a concern. I did some calculations. Normally static oring seals are set up to compress about 18%. From my measuring the correct pin lock oring setup has a 16% compression. A bit lower then standard but still okay. The metric oring you mention has a reduced width and the compress ends up being about 12%. What I think could work is go to a 3mm oring with a reduced ID. The 10mm (ID) x 3mm (W) will have to be stretched over the post, but this would also reduce the width to be close to the standard. This results in about a 20% compression. Just an idea I may get around to trying.

FYI the 2-111 only has a 11% compression. That is why some people have had issues with leaks.

Thanks for the analysis. Does this mean that, as designed, the pin lock connector has non-standard compression or non-standard oring requirements? Given its frequency of use, maybe it was designed with low compression for ease of connection? Of course the low compression results in a higher rate of poor seals and requires added attention to connector alignment.

When I make my next McMaster-Carr order, I will try these: Silicone Oring 10mmx3mm

 

[fifelee]

Thanks for the analysis. Does this mean that, as designed, the pin lock connector has non-standard compression or non-standard oring requirements? Given its frequency of use, maybe it was designed with low compression for ease of connection? Of course the low compression results in a higher rate of poor seals and requires added attention to connector alignment.

"Standard" isn't an exact science and I could have slightly miss-measured the orings and post on my pin locks. Also the plastic connectors I have maybe off a bit as plastic is difficult to accurately manufacture, especially bores. The 16% is from my measuring of my parts. The true pin lock specification maybe 18%. Either way 16% is acceptable. I hope the 3mm work for you. It may be difficult to stretch them that far and as they stretch they will become harder so the connector may be difficult to put on, but you should get a good seal. That said silicone will make stretching easier.

 

[Smashing]

For those ordering Buna, what Dura are you ordering 70or 90?

 

[Spartan1979]

Anyone have any idea what the part number for this oring might be? It is the oversized one for leaky kegs.
http://www.williamsbrewing.com/KEG-LID-SEALING-O-RING-P58C78.aspx

Does any one have an answer for this? I have a keg that leaks around the lid. I can't get it toseal.

 

[Stevo2569]

Does any one have an answer for this? I have a keg that leaks around the lid. I can't get it toseal.

The first post has all the part numbers.

 

[fifelee]

Does any one have an answer for this? I have a keg that leaks around the lid. I can't get it toseal.

A leaky lid is usually due to a bent lid or keg rim. A flat surface and a hammer can straighten a lid. Keg rims are tricky but a hammer, a flat punch, and some patience can fix most leaks.

 

[Nightbiker]

A leaky lid is usually due to a bent lid or keg rim. A flat surface and a hammer can straighten a lid. Keg rims are tricky but a hammer, a flat punch, and some patience can fix most leaks.

Dead-on! But if you still have a little trouble sealing, use a little extra keg lube on the large lid O-ring (and use the silicone one. It is a bit more pliable than the neoprene ring -I keep both in stock, personally) -but as fifelee wrote, the most important thing you could do would be to straighten out any bends or dents. Get it as clean and like the original shape as you can. It doesn't take much to make a seal fail. One last thing you might try: sometimes the lids' "spring" lock gets a bit worn, and I have had to bend the latch a little more toward the inside to make a stronger amount of pressure against the keg (to hold the lid tighter) but be careful -if you don't do it evenly, you could easily end up with a bigger problem than you started with.

 

[Stevo2569]

Let's not forget about the worn keg lid feet. Much easier to replace than bending the handle.

 

[P-J]

A leaky lid is usually due to a bent lid or keg rim. A flat surface and a hammer can straighten a lid. Keg rims are tricky but a hammer, a flat punch, and some patience can fix most leaks.

Well said.

I wrote some information about this a bunch of years ago. It might help someone with lid sealing problems.

Getting Your Keg Lid To Seal

P-J

 

[fifelee]

Well said.

I wrote some information about this a bunch of years ago. It might help someone with lid sealing problems.

Getting Your Keg Lid To Seal

P-J

Great info P-J. Testing the lid without a oring is a good idea. I've had many lids that I couldn't even get to fit right with no oring. Seems the oval shape of the lid and keg rim often don't match. Don't know if they are manufactured different or if the keg rim deformations over time. Either way beating on the rim a bit allow the lid to fit freely.

 

[Spring_Chicken]

Some kegs have one lid that fits them. If I switch lids because I'm cleaning a few at a time they won't seal. Then I have to try each lid on each keg until they all seal. Same with dip tubes. Now I clean one at a time start to finish.

 

[SpeedYellow]

A word of warning about poppet o-rings listed above (McMaster 9396K13): they DO NOT work as replacement o-rings in Firestone / Challenger VI poppets. I tried it, and they leaked profusely, so now I have to buy new poppets. And they certainly don't fit the poppets in Cornelius made kegs. Seems that those o-rings only fit "universal poppets" that you can buy as a replacement part.

 

[NoCornOrRice]

thank you for posting this!

 

[gizmodog51]

Anyone have any idea what the part number for this oring might be? It is the oversized one for leaky kegs.
http://www.williamsbrewing.com/KEG-LID-SEALING-O-RING-P58C78.aspx

yes, i recently ordered two of them and i like them much better than the normal sized "O" rings which are sold for the ligs seals.
i have used kegs purchased a year or so ago from AIHB.

they are expensive but i think i'm gonna buy another two unless those silicon "O" ring from mcmaster are better...they sure are cheaper!
hope this helps.....

GD

 

[RScottyL]

Can you update the pricing for the o-rings, as it looks like it has changed.

You can now order 50 of the silicone ones instead of 100, which will make it easier on the wallet!

I decided to rearrange this post to be a little more straight forward with the information. The bulk of the info provided here was copied/edited/paraphrased from a Dec 2010 post on Homebrew Finds - so a big thanks to Chris (724b). Rather than copying the blog post's text, I have pared down to just the relevant details no so this is easier to read at a glance. The links and numbers below are currently for ball lock kegs, but if you have the numbers/links for the o-rings for pin locks please let me know and I will add them to the list.

• Dip Tube O-rings $1.96/100 - 9452K172
• Dip Tube O-rings Quad Sealing $4.46/100 - 90025K368 (better seal, less force)
• Post O-rings Buna-N $2.15/100 - 9452K23 (liquid post)
• Post O-rings Silicone $10.71/100 - 9396K24 (gas post)
• Lid O-rings Buna-N $12.69/10 - 9452K218
• Lid O-rings Silicone $7.88/5 - 9396K926
• Internal Quick Disconnect O-rings Silicone $6.11/100 - 9396K18 (see notes)

Regarding Buna-N vs Silicone:
Most use Buna-N on the liquid posts because they are cheaper and a liquid leak will be immediately obvoius. Silicone is supposed to seal better, and is generally used for the gas posts. This also has the effect of color coding the posts as Buna-N is black and Silicone is red. Though the keg lid is generally sealing against gas coming out, most use the Buna-N for lid sealing without any problems.

Notes/Additional O-Rings:
I will list extra info and additional o-rings and part numbers here until I have enough to start reorganising it by keg type or similar.

• The o-ring listed for the Internal QD (9396K18) aren't exactly the same as the standard square sided o-ring that comes in quick disconnects, but the HBF author stated they work well for him and I have found this to be true as well.
• Dip Tube Silicone o-rings $9.44/100 - 9396K74 (thanks crazyworld)
• Sanke Keg o-ring $4.67/10 - 9396k215 (thanks dstar26t)
• barrooze reported that the standard post o-rings for ball locks appear to be a bit small in thickness for use on a pin lock post and he will try using the next thickness up (0.139").

 

[tre9er]

100 silicone post o-rings from amazon, $10.13 shipped if you have Prime:

http://www.amazon.com/gp/product/B000FMWNZS/?tag=skimlinks_replacement-20

100 of the buna-n o-rings were $8 and change shipped, so for $2 I'll take silicone

 

[724b]

This is a great deal... thanks for posting!

I just put this up on homebrew finds...
http://www.homebrewfinds.com/2012/11/great-deal-100-keg-post-orings-1013.html

100 silicone post o-rings from amazon, $10.13 shipped if you have Prime:

http://www.amazon.com/gp/product/B000FMWNZS/?tag=skimlinks_replacement-20

100 of the buna-n o-rings were $8 and change shipped, so for $2 I'll take silicone

 

[tre9er]

This is a great deal... thanks for posting!

I just put this up on homebrew finds...
http://www.homebrewfinds.com/2012/11/great-deal-100-keg-post-orings-1013.html

haha, I'm FaaborgBryggeri on twitter, FWIW. Glad to help!

 

[adamant]

How would the 4061T118 compare to the 9396K18.

They are square, but Buna-N.

These are probably too thick. I didn't realize what these o-rings were for until I received them!


Does anyone know if it is possible to replace the small rings on the popets or vents?

 

[tre9er]

I can confirm from this weekend that the cornie post o-rings will ALSO work on a paintball tank. Had one shredded, tank was leaking at "the adapter" and I threw one (from amazon above) on there and all is right-as-rain now.

 

[Floydsview]

When I make my next McMaster-Carr order, I will try these: Silicone Oring 10mmx3mm

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

 

[cwi]

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

Silicone is not a good choice for Corny post Orings, and if used elsewhere in your kegging setup, will just complicate your life with lubricant incompatibilities.

Why silicone is not a good choice for keg posts:
Silicone is only recommended for static placement- like a keg lid or dip tube. It does not hold up well when subjected to dynamic stresses- like removing & replacing keg QDs.

Lubricant incompatibility:
Silicone rubber is not compatible with silicone based lubricants (i.e. "Keg Lube"). A silicone based lube will soften, enlarge, and degrade a silicone rubber Oring making it even more susceptible to dynamic stress damage. This will result in randomly occurring leaks (which I think are more sinister than a leak at initial assembly time).

Silicone is, however, compatible with petrolatum based lubes (Petrol-Gel, Lubri-film, etc.), and they are the most readily available lubes for use with silicone. Buna-n, conveniently, is compatible with both silicone and petrolatum based lubes.

Why you should still care about lubricant incompatibility:
Sankey keg valves (EPDM) and shank/coupler gaskets (Neoprene) are incompatible (highly for EPDM in my experience) with virtually all lubricants made for silicone rubber as most are petroleum based. There are some dual use lubes, but they are prohibitively expensive, hard to source, and have dubious food safiness (any Colbert fans out there?).

So, if you will never encounter EPDM (Sankey), Neoprene (shank/coupler gaskets), or for that matter almost any material besides silicone rubber and Buna-n, you could get away with switching to a single petrolatum based lubricant.

Why there are still no good arguments for using silicone rubber for kegs:
If you have a post that will only seal with a silicone Oring, it would be better to find out why, and fix it. Using a silicone Oring to remedy the situation will likely just cause a random sealing issue after it inevitably fails due to wear.

For dip tubes, given the better sealing properties of the "X-rings" (quad/dual/double seal), and that they have only been found (so far) in Buna-n, there really isn't much of an argument for silicone here either.

For lids, same goes as for posts- find the problem: bent lid, worn feet, bent keg flange,etc., and fix it. (More than likely fixing the issue will make your lids and kegs interchangeable so you don't have a panic situation when you forget which lid goes where with what Oring.) There isn't the danger of dynamic damage with lids, except during handling, but the lubricant issue remains.

Applications where silicone rubber does make sense:
For 'weldless' kettle fittings they are a good choice because of their high heat ratings. It is a static placement, and lube shouldn't be used in this application anyway, so it doesn't cause any lubricant compatibility issues. Although for stainless vessels, getting the fittings welded or soldered is a much better solution- regardless of what Blichmann fanboys have been brainwashed into believing.

Same goes for cam and groove (camlock) fittings. Silicone is a good choice since the fitting may be exposed to high heat; it is (mostly) a static placement; and no lube should be used here either.

 

[Old_mil_guy]

Does anyone know if it is possible to replace the small rings on the popets or vents?

I need the small orings inside the ball lock posts. Anyone have # for those?

 

[alien]

Orings to connect a Sanke keg to a 2" triclamp ferrule (for bottom drain or fermenters) are apparently dash #138, McMaster-Carr 9396K147 in silicone.

 

[jchawk]

Does anyone know the McMaster-Carr part number for the rubber airlock gaskets?

 

[tre9er]

Does anyone know the McMaster-Carr part number for the rubber airlock gaskets?

no, but I think I got mine from Home Depot and IIRC it was a 3/8" grommet.