McMaster Keg O-Ring List

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Gremlyn

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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").
 

crazyworld

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Thanks for posting this! Super helpful since it seems those post o-rings are more likely to go than the lid ones.

For anyone who wants the diptube o-ring in silicone...

* Dip Tube Silicone O-rings $9.44/100 - 9396K74
 

724b

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The quad sealing dip tube o-rings seal a lot more easily.

I wonder if they make quad sealing silicone.
 

barrooze

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Just acquired a mix of 6 kegs and want to get Quad rings for the posts, dip tubes, and QDs. Does anyone know if these o-rings fit both ball lock and pin lock kegs?
 

AlphaKing11

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Just acquired a mix of 6 kegs and want to get Quad rings for the posts, dip tubes, and QDs. Does anyone know if these o-rings fit both ball lock and pin lock kegs?
__________________

I have 1 ball lock and 9 pin lock barrooze.......and I really think you can mix them...someone have other experience???????
 

barrooze

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I have 1 ball lock and 9 pin lock barrooze.......and I really think you can mix them...someone have other experience???????
I ended up getting Keg Cowboy's "Keg O-ring" set and these seem to work very well on both my Pepsi and Coke kegs. To me, this means the o-rings are the same size and interchangeable and I'll be buying the Quad rings the next time around.
 

corkybstewart

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Just acquired a mix of 6 kegs and want to get Quad rings for the posts, dip tubes, and QDs. Does anyone know if these o-rings fit both ball lock and pin lock kegs?
__________________

I have 1 ball lock and 9 pin lock barrooze.......and I really think you can mix them...someone have other experience???????
They are interchangeable-I have about 10 pin locks and a dozen or so ball locks.
 

BrewThruYou

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Thanks for this thread. My LHBS sells the dip tube o-rings for $0.55 a piece, so $4.46 for 100 of them is amazing!
 

barrooze

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It seems that the standard post o-rings for ball locks are a bit small in thickness for use on a pin lock post. I think I am going to try using the next thickness up (0.139") for pin lock posts.
 
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Gremlyn

Gremlyn

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It seems that the standard post o-rings for ball locks are a bit small in thickness for use on a pin lock post. I think I am going to try using the next thickness up (0.139") for pin lock posts.
Thanks! Report back and let me know how it works out. I have added a note that this may be the case to the first post. Can you provide links/part numbers for what you use as well, please?
 

724b

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+1 I'd like to know how this works out for you.

Gremlyn.. I saw the comment about
Thanks! Report back and let me know how it works out. I have added a note that this may be the case to the first post. Can you provide links/part numbers for what you use as well, please?
 

barrooze

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Thanks! Report back and let me know how it works out. I have added a note that this may be the case to the first post. Can you provide links/part numbers for what you use as well, please?
Will do. :ban:
 

ocluke

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The quad sealing dip tube o-rings seal a lot more easily.

I wonder if they make quad sealing silicone.
+1 on this. Does anyone know if there is a silicone version of the quad sealing dip tube buna-n o-ring (#90025K368)?
 
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Does anyone know what the actual lid Oring size on the older 10gal screw top kegs? I sort of fashioned my own for fermentations out of vinyl tube, but would like a proper oring. As best as I can figure it's 1/4" and about 4 5/8" however I can't find anything that size. I likely need to buy stock and a splicing kit.

Any ideas?
 

garysherck

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Thanks for sharing this organized information to help with the re-building of my kegs, as I have gas leaking.

Perhaps, you might consider adding crayzworld's suggestion for Dip Tube Silicone O-rings @ $9.44/100 #9396K215 to your Master List, rather than in the notes (I missed it on my first read).

Since I am still learning, will you tell me where is the "internal disconnect O-ring" located? I assume it is in the pull-up valve that allows air/CO2 to escape thru the lid. However the word "quick disconnect" has me confused. Would you replace this O-ring at the same time you are re-building the keg?
 

724b

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Quick disconnect in this case is referring to cornelius keg disconnects. These connect cornelius style kegs to gas and liquid tubing. There is a small oring inside of each one of these. They are easy to lose, usually when you're cleaning the quick disconnect, so it's nice to have extras of these on hand.
 

garysherck

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Thanks. Now, I understand.

Do you think one of these O-Rings (039K18 ($6.11/100) can be the reason I have a CO2 leak in my system. I will replace the gas o-ring.

I was thinking of this test. First, turn the gas on from the regulator to the grey ball lock connection, then put the connection in water, looking for bubbles. Also test the tank and regulator connections for leaking. If no leaks are found, replace that O-Ring for the internal quick disconnect.

My beer side and the lid o-rings appear to be OK.

Is there any gauge available to test to see if a pressurized empty cornelius keg is maintaing pressure over a period of time. This is my first encounter with a CO2 going empty real fast.
 

724b

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The internal QD oring is, probably, not the source of the leak. That's just my gut feeling. You can test that easily by spraying some soapy water or star san onto the top of the QD, no bubbles, no leak. I say it's probably not, because the force of the top of the QD screwed down on the oring, should be plenty to keep it sealed. That oring would

I'd spray everything you can down first and check for bubbles.

One pesky leak that's difficult to find is the gas post oring. I've lost a lot of CO2 because of this oring. It's difficult to test because you cannot spray soapy water on that oring while it's working. The QD is covering it up. I replace these liberally.

I use a technique I've dubbed the "pressure gauge method" of testing for leaks. Described on this page Homebrew Finds: Tips It's tip 6. It does not require any additional equipment and can be a good indicator of a leak. Check it out.
 

garysherck

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Along with the other good information you have provided, I have checked out all the tips on Homebrew Finds, a really good find. Thanks.
 

danorocks17

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this is extremely helpful! If anyone knows, what is a ballpark shipping rate for ordering a set of each?
 

garysherck

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For my recent order (12/21) for O-Rings of $45.43, the shipping was $4.60. I live in Ohio and also pay sales tax. They may only ship UPS. As others have said, they ship FAST. A few years ago, I used Customer Pick-up for some vales and noticed a UPS tailer was connected to the shipping area.

For that order, I only paid sales tax and was told the total amount of the order when I placed it online. This was my first shipped order; I think the cost is based on weight and distance. Their online ordering system may not have the ability to tell you the shipping amount for small orders.

My guess for O-Rings the shipping would be five or six dollars.
 

724b

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McMaster is very fast and cheap. They must have some special deal with UPS.
 

Schalk79

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Thanks for the info... The o-ring models listed work perfect on our ball lock kegs...

We just scored a good deal on 40 ball lock kegs.
Pretty sure all of them will have to be rebuilt.

Which o-rings work best for the Pin Lock posts?

I buy o-rings from our local bearing suppliers. McMaster refuses to ship to South Africa and our local home brewing shops are a rip-off they charge $15 for s kit consisting of 2x post rings and 1 lid ring.
 

barrooze

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Which o-rings work best for the Pin Lock posts?
I'm glad you asked. I've been meaning to post an update. I got my order of o-rings in a couple days ago and had ordered the slightly larger thickness for the pin lock post ring. I found that the slightly larger thickness (0.139", p/n: AS568A-205) is actually too big to fit in the post groove! Because the ring thickness is a couple thous too large, the ring doesn't actually fit inside the groove, making it impossible to fit the QD onto the post. I'm curious to see if the ring with a slightly smaller ID (p/n: AS568A-204) would force the ring into the groove better, but I'm not going to be trying this in the near future.

At this time, I recommend going with the listed Post ring size for Pin Lock posts.
Post O-rings Buna-N $2.15/100 - 9452K23 (liquid post)​
Post O-rings Silicone $10.71/100 - 9396K24 (gas post)​
 

Nightbiker

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Just wanted to add my thanks for this thread! I just placed an order for all of the O-rings (silicone all around -except for the beer posts -those got buna) for my kegs, and will have quite a few to put in my parts bins (grin -I HATE needing an O-ring and not having it).
 

Nightbiker

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pretty fast service! I got 'em in 2 days. Wow it would be great if everyone offered service like that! Their seals are a really great bargain -a lot of their other stuff seems a bit high, but if (when) I'm in a pinch, I'll gladly pay a bit more for fast service. Can't believe the number of different O-rings/seals they offer! I think I'll stock up on some other ones for other things I have to re-seal from time to time.
 

barrooze

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Can't say what o-ring that is, but B&S has several different poppets available. You could see if they have one that makes a better seal for you. Worked for me!
 

ocluke

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I received the my order based on this list. Thanks for the info.

I went to take my keg apart and I didn't have a new ring for the poppet valve (ball lock).
Anyone know what it is? Or is this different depending on manufacture?

This looks like mine:
http://www.amazon.com/dp/B006C4WJ1G/?tag=skimlinks_replacement-20
It depends on what style of keg you have. If you're just trying to replace the little ring on it, maybe someone else can chime in. If you want to go clean with a new poppet, there are several different versions at MidwestSupplies.
 
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