Deciding on 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 sturdy since they’ve turn into extra accessible to homebrewers.
This put up goes to check out all three, with the aim of serving to your select the appropriate materials on your utility.
However first issues first, let’s speak about meals protected supplies…
Meals Protected Supplies for Keg O-Rings?
A lot of the o-rings which can be marketed to homebrewers don’t declare to be meals protected.
In my expertise, it’s extraordinarily tough to seek out choices that declare to be protected for meals contact. Possibly a number of the o-rings which can be accessible are meals protected, however only a few are literally labeled as such.
However why? One potential cause… they aren’t meals protected. Past that, one business insider I spoke with mentioned 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 protected choice.
- Simply because an o-ring is marketed to be used in a keg doesn’t robotically imply that the supplies and manufacturing processes used are meals protected.
- If you concentrate on it from a random provider or producer’s perspective… they don’t know what you’re placing in your keg, possibly 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 produced from [fill in material here] are meals protected. Sure high quality requirements and processes are required.
One notable provider options all meals protected o-ring choices.
Typically talking, meals protected o-rings might value a bit extra, however, we’re, typically, solely speaking a couple of cents per o-ring. It’s value it.
If you happen to’re utilizing your keg for something meals associated (beer=meals)… My suggestion is to buy o-rings made out of fabric protected for meals contact.
Compound Choice – Evaluating EPDM, Silicone and Buna-N
Terminology
- Compression Set Resistance – A measurement of the power of a substance to return to it’s unique thickness after long run compression.
- Compressibility – How nicely 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 nicely can nicely can air or oxygen transverse a compound. That is measured in several methods, I’m going to generalize labeling supplies wonderful 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: Glorious
Buna-N/Nitrile is mostly the most affordable materials accessible for keg o-rings. It has low permeability, meaning much less uptake of off smells and flavors. Virtually talking Buna-N generally has an off scent that brewers don’t like. It’s additionally not practically pretty much as good at returning to type as silicone. That may result in flat spots and poor sealing.
Advisable For: Provided that funds is a principal issue. If you happen to’re going to attempt to save cash by utilizing Buna-N, I recommend frequently and completely checking for leaks and proactively changing o-rings. See under for a straightforward to recollect schedule. I might chorus from utilizing Buna-N on gasoline posts. This can be 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: Glorious
- Low permeability: Good
Silicone is mostly extra compressible than Buna-N. Silicone additionally stays softer at cool temperatures. Due to this, silicone typically supplies the perfect seal of the three compounds listed right here.
Advisable For:
- Posts and Dip Tubes – Silicone gives the perfect seal and that’s essential in the case of gasoline posts. These are low-cost on a per o-ring foundation so you possibly can exchange frequently to fight absorbed off smells and odors, which silicone has extra of an inclination to select up. These spots even have a small floor space so oxygen ingress isn’t a serious challenge.
- Keg Lid –
- Particularly if tour keg lid or opening is dinged up or misshapen. Silicone offers you the perfect probability of getting a great seal in lower than good circumstances.
- If you happen to’re ageing beers for a very long time, contemplate EPDM
A Be aware on Gasoline O-rings I’m fast to switch gasoline o-rings. A leak on the put up 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 vary these liberally.
EPDM
- Compound: Ethylene Propylene
- Working Temperature: -65 F / 300 F
- Typical Durometer: 70A
- Compression Set Resistance: Good
- Low permeability: Glorious
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. Which means they’re much less porous and extra proof against absorbing off-smells and off-flavors.
Till lately, these haven’t been accessible to homebrewers, or a minimum of simply accessible. Valuebrew now gives these in bulk portions at an affordable value, albeit dearer than silicone and Buna-N.
Advisable For:
- Keg Lids – particularly when your beers might be aged in keg.
- Dip Tubes and Posts. IF you’re keg is in wonderful situation…
I’m going to cite Valuebrew’s materials choice steerage from their EPDM dip tube providing, as a result of it’s nicely said.
EPDM’s good thing about 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 wonderful situation and also you’re prepared to spend a bit more cash, EPDM is a superb choice. If it’s dinged up, I’d go along with silicone.
BEWARE Of: Dip Tube O-Ring Purposes
Typically talking keg o-rings are normal sizes. There are some uncommon outliers on the market, dip tube o-rings appear to be the more than likely to be non-standard. For my part, finest follow is to hold on to your originals so you possibly can examine with replacements. Within the occasion that your keg has non-standard dip tube o-rings, you need to contact the producer for replacements. Luckily it is a uncommon challenge, normal sizes match the overwhelming majority of kegs.
If you wish to attempt EPDM in your dip tubes, you need to test for leaks. In case your keg varies from normal even barely you might get a leak with substitute EPDM o-rings. Valuebrew suggests shopping for each when you’re going to attempt EPDM on the dip tube location.
Concern: Oxygen Pickup from the Lid O-Ring
The next is from Kee Doery through a dialog we had relating to o-ring materials choice. Kee is likely one of the individuals behind Kegland. Kegland is making some wonderful issues for homebrewers! Try our giant library of Kegland evaluations.
In the mean 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 nicely when the lid isn’t on straight. With that mentioned one main challenge is that silicone has very excessive oxygen transmission charge. For example because the lid o-ring is so giant it has a whole lot of floor space and thus has a considerable impression on oxygen transmission.
Commercially we might contemplate 100ppb oxygen within the beer to be the restrict of oxygen to get into the beer earlier than we contemplate mild colored beers to be oxidised. With a silicone o-ring this 100ppb oxygen restrict might 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 lengthen the life considerably. The second hand previous cornelius kegs used nitrile rubber which was greater than 20 occasions higher than silicone with respect to oxygen transmission however has the primary challenge that when below stress for a while would get flat spots on the o-ring and never spring again nicely.
So…. oxygen ingress from a keg lid can have a destructive impression on the beer as rapidly as 1 to 4 months. This results in my suggestion above to make use of EPDM for keg lids.
Sourcing O-Rings
How Typically Ought to You Exchange Keg O-Rings?
As said beforehand, I believe you need to exchange all keg o-rings if you refurbish or receive a used keg.
What about after that? In fact, you can simply maintain utilizing them till they break, they scent or look horrible or… till you lose a tank of CO2 attributable to 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. In some unspecified time in the future, supplies might turn into brittle. Past shelf life, o-rings put on out from use – compression and abrasion. The opposite potential challenge is supplies compatibility. Do your o-rings break down from the chemical compounds you topic them to?
Keg producer AEB says to switch o-rings yearly. AEB produces a number of the finest kegs in the marketplace and I agree with the one 12 months generally. Due to their very low value, I recommend altering excessive contact, excessive danger leak o-rings extra typically.
Excessive Danger:
- Publish o-rings: Particularly gasoline. Leaks originating from gasoline put up very tough to detect.
- Gasoline dip tube o-rings: Leaks listed below are simpler to detect, however I additionally classify these as excessive danger. A leak at both the gasoline put up or gasoline dip tube is invisible and has irritating penalties… heading to your CO2 supply to swap or fill a tank. Higher protected than sorry.
Excessive Contact: Inner 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. Commonly changing, prices little or no and helps stave off undesirable off flavors, leaks and misplaced CO2. This schedule ought to maintain your kegs working nice from a gasket perspective.
The one gaskets which can be a bit dearer are lid o-rings. If you happen to wished to get a bit extra life out of these, you can exchange lid o-rings in odd years when Daylight Financial savings Time Ends (Fall). This could make them two years previous after 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’ll be worn out and even when they aren’t they’ll scent of soda pre-mix. Past that, who is aware of what they’re produced from. Begin with a clear slate. As you noticed earlier, the o-rings on this keg had been a grubby mismatch of soda drenched o-rings
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Be aware: Acknowledged materials specs are common, precise specs will fluctuate from provider to provider.
Be sure that the elements you utilize are appropriate and rated on your supposed utility. Contact producer with questions on suitability or a selected utility. At all times learn and observe producer instructions. toppost:oringmaterials tag:tpr
