Choosing the Proper Materials for Keg O-Rings
I might enterprise a guess that Silicone and Buna-N are the 2 mostly used compounds for keg o-rings. EPDM, which has been the selection of execs for a very long time, might be a distant third, however approaching robust since they’ve change into extra accessible to homebrewers.
This publish goes to check out all three, with the objective of serving to your select the proper materials to your utility.
However first issues first, let’s discuss meals secure supplies…
Meals Protected Supplies for Keg O-Rings?
Many of the o-rings which can be marketed to homebrewers don’t declare to be meals secure.
In my expertise, it’s extraordinarily tough to seek out choices that declare to be secure for meals contact. Possibly among the o-rings which can be obtainable are meals secure, however only a few are literally labeled as such.
However why? One potential cause… they aren’t meals secure. Past that, one trade insider I spoke with stated suppliers have a possible downside with success. Since many choices and supplies can be found, It’s tough for some distributors or sellers to ensure you’re getting a meals secure choice.
- Simply because an o-ring is marketed to be used in a keg doesn’t mechanically imply that the supplies and manufacturing processes used are meals secure.
- If you concentrate on it from a random provider or producer’s perspective… they don’t know what you’re placing in your keg, perhaps it’s not even meals. The issue that we, as homebrewers, have is is… beer is meals and meant for human consumption.
- You can not say all o-rings constituted of [fill in material here] are meals secure. Sure high quality requirements and processes are required.
One notable provider options all meals secure o-ring choices.
Typically talking, meals secure o-rings could price somewhat extra, however, we’re, usually, solely speaking just a few cents per o-ring. It’s price it.
For those who’re utilizing your keg for something meals associated (beer=meals)… My advice is to buy o-rings made out of fabric secure for meals contact.
Compound Choice – Evaluating EPDM, Silicone and Buna-N
Terminology
- Compression Set Resistance – A measurement of the flexibility of a substance to return to it’s authentic thickness after long run compression.
- Compressibility – How effectively can a cloth compress to make a top quality seal? That is associated to hardness, however virtually it’s not precisely the identical factor. Most keg o-rings are the identical hardness, 70A, but we see Silicone sealing higher than Buna-N.
- Permeability – How effectively can effectively can air or oxygen transverse a compound. That is measured in numerous methods, I’m going to generalize labeling supplies glorious or good.
- Typical Durometer – A measurement of the hardness of a cloth
Buna-N
- Compound: Nitrile-butadiene
- Working Temperature: -30 F / 250 F
- Typical Durometer: 70A
- Compressibility: Truthful
- Compression Set Resistance: Good
- Low permeability: Wonderful
Buna-N/Nitrile is mostly the most cost effective materials obtainable for keg o-rings. It has low permeability, meaning much less uptake of off smells and flavors. Virtually talking Buna-N typically has an off odor that brewers don’t like. It’s additionally not almost pretty much as good at returning to type as silicone. That may result in flat spots and poor sealing.
Really useful For: Keg lid o-rings if funds is a driving issue. Particularly for beers that you just plan to age. Buna-N has decrease oxygen permeability in comparison with silicone. For those who can’t afford EPDM for that utility, Buna-N is an efficient. For those who’re going to strive to save cash through the use of Buna-N, I recommend usually and completely checking for leaks and proactively changing o-rings. See under for a simple to recollect schedule. I might chorus from utilizing Buna-N on fuel posts. It is a onerous spot to test for leaks and you can not see leaking CO2.
Silicone
- Compound: Silicone
- Working Temperature: -58 F / 450 F
- Typical Durometer: 70A
- Compression Set Resistance: Wonderful
- Low permeability: Good
Silicone is mostly extra compressible than Buna-N. Silicone additionally stays softer at cool temperatures. Due to this, silicone usually gives the very best seal of the three compounds listed right here.
Really useful For:
- Posts and Dip Tubes – Silicone affords the very best seal and that’s crucial in the case of fuel posts. These are low-cost on a per o-ring foundation so you possibly can exchange usually to fight absorbed off smells and odors, which silicone has extra of a bent to select up. These spots even have a small floor space so oxygen ingress is just not a serious problem.
- Keg Lid –
- Particularly if tour keg lid or opening is dinged up or misshapen. Silicone will provide you with the very best likelihood of getting an excellent seal in lower than excellent situations.
- For those who’re getting older beers for a very long time, contemplate EPDM
A Be aware on Gasoline O-rings I’m fast to exchange fuel o-rings. A leak on the publish is especially tough to check for. I’ve misplaced a number of tanks of CO2 earlier than studying this lesson. In bulk, these are low-cost, exchange them liberally. See my part on keg o-ring life under, however my suggestion is to alter these liberally.
EPDM
- Compound: Ethylene Propylene
- Working Temperature: -65 F / 300 F
- Typical Durometer: 70A
- Compression Set Resistance: Good
- Low permeability: Wonderful
EPDM is a favourite of many professional brewers for sure functions. It has some actual benefits over silicone. One of many large ones is a a lot decrease permeability. Meaning they’re much less porous and extra immune to absorbing off-smells and off-flavors.
Till not too long ago, these haven’t been obtainable to homebrewers, or not less than simply obtainable. Valuebrew now affords these in bulk portions at an inexpensive value, albeit dearer than silicone and Buna-N.
Really useful For:
- Keg Lids – particularly when your beers will probably be aged in keg.
- Dip Tubes and Posts. IF you’re keg is in glorious situation…
I’m going to cite Valuebrew’s materials choice steering from their EPDM dip tube providing, as a result of it’s effectively acknowledged.
EPDM’s advantage of decrease permeability and fewer uptake of off smells and flavors equates to much less compressibility.
So, EPDM has some nice advantages, however the commerce off is that it might not seal in addition to silicone. in case your keg is in glorious situation and also you’re keen to spend somewhat more cash, EPDM is a superb choice. If it’s dinged up, I’d go together with silicone.
BEWARE Of: Dip Tube O-Ring Purposes
Typically talking keg o-rings are commonplace sizes. There are some uncommon outliers on the market, dip tube o-rings appear to be the almost definitely to be non-standard. For my part, finest observe is to hold on to your originals so you possibly can evaluate with replacements. Within the occasion that your keg has non-standard dip tube o-rings, you need to contact the producer for replacements. Fortuitously this can be a uncommon problem, commonplace sizes match the overwhelming majority of kegs.
If you wish to strive EPDM in your dip tubes, you need to test for leaks. In case your keg varies from commonplace even barely you could get a leak with substitute EPDM o-rings. Valuebrew suggests shopping for each for those who’re going to strive EPDM on the dip tube location.
Difficulty: Oxygen Pickup from the Lid O-Ring
The next is from Kee Doery by way of a dialog we had relating to o-ring materials choice. Kee is among the individuals behind Kegland. Kegland is making some superb issues for homebrewers! Try our massive library of Kegland critiques.
In the intervening time the vast majority of keg manufactures together with ourselves have been utilizing silicone o-rings for the lid o-rings. Silicone has good “spring” properties and bounces again very well. It’s additionally mushy so it seals effectively when the lid is just not on straight. With that stated one main problem is that silicone has very excessive oxygen transmission charge. For example because the lid o-ring is so massive it has a number of floor space and thus has a considerable affect on oxygen transmission.
Commercially we’d contemplate 100ppb oxygen within the beer to be the restrict of oxygen to get into the beer earlier than we contemplate gentle colored beers to be oxidised. With a silicone o-ring this 100ppb oxygen restrict will probably be reached about 1-4 months of being saved. (at colder temperatures the transmission charge is much less which is one other good cause to retailer the kegs chilly). If we use different rubbers we will prolong the life considerably. The second hand outdated cornelius kegs used nitrile rubber which was greater than 20 occasions higher than silicone with respect to oxygen transmission however has the primary problem that when beneath stress for a while would get flat spots on the o-ring and never spring again effectively.
So…. oxygen ingress from a keg lid can have a unfavorable affect on the beer as shortly as 1 to 4 months. This results in my advice above to make use of EPDM for keg lids.
Sourcing O-Rings
How Typically Ought to You Change Keg O-Rings?
As acknowledged beforehand, I feel you need to exchange all keg o-rings while you refurbish or acquire a used keg.
What about after that? In fact, you might simply preserve utilizing them till they break, they odor or look horrible or… till you lose a tank of CO2 resulting from an o-ring associated leak. On the opposite finish of the spectrum some individuals change o-rings each time they keg.
Relying on materials, keg o-rings have a shelf life. Sooner or later, supplies could change into brittle. Past shelf life, o-rings put on out from use – compression and abrasion. The opposite potential problem is supplies compatibility. Do your o-rings break down from the chemical compounds you topic them to?
Keg producer AEB says to exchange o-rings yearly. AEB produces among the finest kegs in the marketplace and I agree with the one yr most often. Due to their very low price, I recommend altering excessive contact, excessive danger leak o-rings extra typically.
Excessive Danger:
- Publish o-rings: Particularly fuel. Leaks originating from fuel publish very tough to detect.
- Gasoline dip tube o-rings: Leaks listed here are simpler to detect, however I additionally classify these as excessive danger. A leak at both the fuel publish or fuel dip tube is invisible and has irritating penalties… heading to your CO2 supply to swap or fill a tank. Higher secure than sorry.
Excessive Contact: Inside QD and Common Poppet O-Rings. These contact each ounce of beer that’s poured.
I recommend utilizing Daylight Financial savings dates as a reminder. One thing like this…
Most of those o-rings are pennies every when purchased in cheap bulk portions. Usually changing, prices little or no and helps stave off undesirable off flavors, leaks and misplaced CO2. This schedule ought to preserve your kegs working nice from a gasket perspective.
The one gaskets which can be somewhat dearer are lid o-rings. For those who wished to get somewhat extra life out of these, you might exchange lid o-rings in odd years when Daylight Financial savings Time Ends (Fall). This is able to make them two years outdated once they’re changed.
Why exchange o-rings even when they’re holding stress?
For my part, you’re going to wish to exchange all of the o-rings in your keg. Typically talking they will be worn out and even when they aren’t they’ll odor of soda pre-mix. Past that, who is aware of what they’re constituted of. Begin with a clear slate. As you noticed earlier, the o-rings on this keg have been a grubby mismatch of soda drenched o-rings
Sanitizing O-Rings in Star San?
Keg o-ring supplies – Silicone, EPDM and Buna-N – are usually appropriate with Star San. Nonetheless that doesn’t imply that you could soak these in Star San endlessly.
Star Stan may finally harm o-ring (and many different issues) given extreme publicity. Contact time for Star San is 5 minutes. That’s about how lengthy you need to go away an element sitting in Star San.
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Be aware: Said materials specs are normal, precise specs will differ from provider to provider.
Be certain the parts you employ are appropriate and rated to your meant utility. Contact producer with questions on suitability or a particular utility. All the time learn and comply with producer instructions. toppost:oringmaterials tag:tpr
