Deciding on the Proper Materials for Keg O-Rings
I’d 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 change into extra accessible to homebrewers.
This submit goes to check out all three, with the aim of serving to your select the suitable materials to your utility.
However first issues first, let’s discuss meals protected supplies…
Meals Secure Supplies for Keg O-Rings?
Many of the o-rings which can be marketed to homebrewers don’t declare to be meals protected.
In my expertise, it’s extraordinarily troublesome to seek out choices that declare to be protected for meals contact. Perhaps among the o-rings which can be obtainable 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 achievement. Since many choices and supplies can be found, It’s troublesome for some distributors or sellers to ensure you’re getting a meals protected possibility.
- 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 consider 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 made out of [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.
Usually talking, meals protected o-rings might value slightly extra, however, we’re, typically, solely speaking just a few cents per o-ring. It’s value it.
When you’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 properly can a fabric compress to make a high 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 properly can properly can air or oxygen transverse a compound. That is measured in numerous methods, I’m going to generalize labeling supplies wonderful or good.
- Typical Durometer – A measurement of the hardness of a fabric
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 usually the most cost effective materials obtainable for keg o-rings. It has low permeability, which means much less uptake of off smells and flavors. Virtually talking Buna-N typically has an off scent 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 helpful For: Keg lid o-rings if finances is a driving issue. Particularly for beers that you just plan to age. Buna-N has decrease oxygen permeability in comparison with silicone. When you can’t afford EPDM for that utility, Buna-N is an efficient. When you’re going to strive to economize by utilizing Buna-N, I counsel repeatedly and completely checking for leaks and proactively changing o-rings. See under for a straightforward to recollect schedule. I’d chorus from utilizing Buna-N on fuel posts. This can be a arduous spot to test for leaks and you can’t see leaking CO2.
Silicone
- Compound: Silicone
- Working Temperature: -58 F / 450 F
- Typical Durometer: 70A
- Compression Set Resistance: Wonderful
- Low permeability: Good
Silicone is usually extra compressible than Buna-N. Silicone additionally stays softer at cool temperatures. Due to this, silicone typically gives one of the best seal of the three compounds listed right here.
Really helpful For:
- Posts and Dip Tubes – Silicone presents one of the best seal and that’s essential in relation to fuel posts. These are low-cost on a per o-ring foundation so you’ll be able to substitute repeatedly 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 isn’t a serious problem.
- Keg Lid –
- Particularly if tour keg lid or opening is dinged up or misshapen. Silicone offers you one of the best probability of getting an excellent seal in lower than good circumstances.
- When you’re getting old beers for a very long time, think about EPDM
A Be aware on Gasoline O-rings I’m fast to switch fuel o-rings. A leak on the submit is especially troublesome to check for. I’ve misplaced a number of tanks of CO2 earlier than studying this lesson. In bulk, these are low-cost, substitute 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 purposes. 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 immune to absorbing off-smells and off-flavors.
Till not too long ago, these haven’t been obtainable to homebrewers, or no less than simply obtainable. Valuebrew now presents these in bulk portions at an inexpensive value, albeit dearer than silicone and Buna-N.
Really helpful For:
- Keg Lids – particularly when your beers will probably 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 steering from their EPDM dip tube providing, as a result of it’s properly acknowledged.
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 could not seal in addition to silicone. in case your keg is in wonderful situation and also you’re prepared to spend slightly more cash, EPDM is a superb possibility. If it’s dinged up, I’d go along with silicone.
BEWARE Of: Dip Tube O-Ring Purposes
Usually talking keg o-rings are customary sizes. There are some uncommon outliers on the market, dip tube o-rings appear to be the more than likely to be non-standard. In my view, greatest observe is to hold on to your originals so you’ll be able to evaluate with replacements. Within the occasion that your keg has non-standard dip tube o-rings, it is best to contact the producer for replacements. Fortuitously this can be a uncommon problem, customary sizes match the overwhelming majority of kegs.
If you wish to strive EPDM in your dip tubes, it is best to test for leaks. In case your keg varies from customary even barely chances are you’ll 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.
Challenge: 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 folks behind Kegland. Kegland is making some superb issues for homebrewers! Try our massive library of Kegland evaluations.
For the time being 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 rather well. It’s additionally smooth so it seals properly when the lid isn’t on straight. With that mentioned one main problem is that silicone has very excessive oxygen transmission price. As an example because the lid o-ring is so massive it has loads of floor space and thus has a considerable impression on oxygen transmission.
Commercially we might think about 100ppb oxygen within the beer to be the restrict of oxygen to get into the beer earlier than we think about 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 price is much less which is one other good cause to retailer the kegs chilly). If we use different rubbers we are able to prolong the life considerably. The second hand outdated cornelius kegs used nitrile rubber which was greater than 20 instances higher than silicone with respect to oxygen transmission however has the principle problem that when beneath strain for a while would get flat spots on the o-ring and never spring again properly.
So…. oxygen ingress from a keg lid can have a unfavourable 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 Usually Ought to You Substitute Keg O-Rings?
As acknowledged beforehand, I feel it is best to substitute all keg o-rings once you refurbish or acquire a used keg.
What about after that? In fact, you may simply preserve 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 folks change o-rings each time they keg.
Relying on materials, keg o-rings have a shelf life. Sooner or later, supplies might 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 substances you topic them to?
Keg producer AEB says to switch o-rings yearly. AEB produces among the greatest kegs in the marketplace and I agree with the one 12 months generally. Due to their very low value, I counsel altering excessive contact, excessive danger leak o-rings extra typically.
Excessive Threat:
- Submit o-rings: Particularly fuel. Leaks originating from fuel submit very troublesome 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 submit or fuel 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: Inside QD and Common Poppet O-Rings. These contact each ounce of beer that’s poured.
I counsel 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. Frequently 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 slightly dearer are lid o-rings. When you wished to get slightly extra life out of these, you may substitute lid o-rings in odd years when Daylight Financial savings Time Ends (Fall). This might make them two years outdated after they’re changed.
Why substitute o-rings even when they’re holding strain?
In my view, you’re going to wish to substitute all of the o-rings in your keg. Usually talking they’re going to 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 made out 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
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Be aware: Said materials specs are common, precise specs will range from provider to provider.
Ensure the elements you utilize are appropriate and rated to your meant utility. Contact producer with questions on suitability or a particular utility. All the time learn and observe producer instructions. toppost:oringmaterials tag:tpr
