How big's your O2 tank?

[somenerve]

What's the minimum size O2 tank you'd want to have on hand for a 3 bbl brewhouse? Am looking at them on eBay and they come in a lot of different sizes! How many liters are used in an average 3 bbl batch?

[Yellowbeard]

Unless gas suppliers are a lot different in your area, you probably don't want to buy an oxygen tank.

You'll find that it's difficult to get *your* tank filled. Most gas suppliers swap for full tanks and then fill everything at a central location on their own schedule. So the first time you walk in with your tank (assuming its hydrotest date hasn't expired - another thing to watch for in used tank sales) they'll want to put you on a swap contract anyway.

So just cut to the chase and get a contract from your local gas supplier. Google "welding supply" or "welding gas" because any of these companies will have oxygen on hand. Welding grade gas is (in most people's opinion) perfectly fine - welders can't cope with contaminated gas so welding O2 is quite clean & pure. But if you want extra purity go for Aviator's grade.

When you're on a contract, you pay a yearly fee per tank plus a smaller fee every time you swap an empty tank for a full one. You can add or subtract tanks from your contract pretty easily, and they usually have pickup/deliver pretty cheap. If you need CO2 set that up at the same time.

If you have 2 tanks, you just call them whenever one runs empty and they'll come swap it within a few days while you're using the other tank. In general, you're looking at $75-$250 per year for the various standard tank sizes, and maybe $25-$50 every time you swap an empty tank.

[Yellowbeard]

I'd love to see other people chime in here, but for calculating the amount to inject you need to (a) know your wort flow rate if oxygenating inline (b) do some math and (c) know, or guess, how much O2 is actually dissolving into the wort. There's no way to be sure without a dissolved oxygen meter, unfortunately.

Your O2 regulator will probably show the liters per minute of flow.

At 70 degrees, a liter of oxygen is 1.43 grams (or 1430 milligrams)

You want about 8 ppm (parts per million) oxygen in your wort.

So if it dissolved perfectly, a liter of O2 would oxygenate about 178 liters (47 gallons) of wort.

But it never dissolves perfectly. The efficiency of dissolution depends on contact time, surface area (bubble size), temperature, and specific gravity.

[foestauf]

So just cut to the chase and get a contract from your local gas supplier. Google "welding supply" or "welding gas" because any of these companies will have oxygen on hand. Welding grade gas is (in most people's opinion) perfectly fine - welders can't cope with contaminated gas so welding O2 is quite clean & pure. But if you want extra purity go for Aviator's grade.

Just to add to this. As it is my understanding (I am by no means an expert on oxygen heh) welding oxygen is about 99% pure and medical grade oxygen is 99.9% pure. The general consensus is that extra .9% is in no way worth the cost you will pay for medical grade oxygen, and don't go stealing gam gam's oxygen bottles neither.

[jebzter]

The welding grade stuff is the same as the medical in most cases. This is due to several factors, one being its way more cost effective if the refining equipment just makes one purity then having several systems to have several grades, the second is that most contaminants don't react well to pure oxygen environments, so the bottles must be very clean, especially free of hydrocarbons. That said, oxygen is cheap, we get a K sized tank for $20 and change, lasts about a month for us on a 10bbl system. I wouldn't worry too much about the size, the tanks do not vent so you can take as long as you want to use it.

[rdcpro]

Just to add to this. As it is my understanding (I am by no means an expert on oxygen heh) welding oxygen is about 99% pure and medical grade oxygen is 99.9% pure. The general consensus is that extra .9% is in no way worth the cost you will pay for medical grade oxygen, and don't go stealing gam gam's oxygen bottles neither.

This is probably more information than anyone needs to know, but oxygen is sold (at least by Praxaire) by the number of "nines". So grade "6" is 6 nines pure: 99.9999%. I have no idea what the welding supply sells, but most likely it's the lowest grade, which for Praxaire is 2.6. That's 99.6%. There are specialty grades for semiconductor use, but you won't find these at your welding supply. I used to work for a company that made UHP gas purifiers, and we bought literally truckloads of cyrogenic oxygen from Praxaire, which was 99.993%.

99.6% is a curious number, because that's what the minimum purity is for USP grade Oxygen. So, AFAIK, all oxygen in the US is at least USP grade (medical grade), because it's not cost effective to have bulk storage for multiple grades. The main difference is how the cylinder is filled and labeled. But the oxygen is the same for both "technical" and "medical" grade.

Short answer (IMHO): Oxygen is Oxygen, as far as brewers are concerned. Put a sterile filter inline, and don't worry about trace amounts of argon, CO2 or nitrous oxide.

In case you're really curious, here's some good bathroom reading:

http://www.praxair.com/~/media/praxairus/Documents/Specification%20Sheets%20and%20Brochures/Gases/Oxygen/Oxygen%20O2%20Spec%20Sheet%20SS%20P4638.pdf?la=en

And no, <0.1 ppm THC doesn't mean what you think.

Regards,
Mike

[somenerve]

Excellent! Thank you for the awesome input everyone!

[Tim DHBC]

I have a 40ft^3 tank on a 7bbl system and I swap my tank every 3-4 brews. It costs about $13.50 to swap the tank. Initial cost of the tank was about $100. The welding supply company I use is practically next door. I had to find a O2 regulator at a national fire fighter Corp for an additional $50/or so. From what I have read in the yeast book from the brewer's association it is hard to over O2 wort before fermentation. Just my experience so far. Good luck!

[LSN2]

This is probably more information than anyone needs to know, but oxygen is sold (at least by Praxaire) by the number of "nines". So grade "6" is 6 nines pure: 99.9999%. I have no idea what the welding supply sells, but most likely it's the lowest grade, which for Praxaire is 2.6. That's 99.6%. There are specialty grades for semiconductor use, but you won't find these at your welding supply. I used to work for a company that made UHP gas purifiers, and we bought literally truckloads of cyrogenic oxygen from Praxaire, which was 99.993%.

99.6% is a curious number, because that's what the minimum purity is for USP grade Oxygen. So, AFAIK, all oxygen in the US is at least USP grade (medical grade), because it's not cost effective to have bulk storage for multiple grades. The main difference is how the cylinder is filled and labeled. But the oxygen is the same for both "technical" and "medical" grade.

Short answer (IMHO): Oxygen is Oxygen, as far as brewers are concerned. Put a sterile filter inline, and don't worry about trace amounts of argon, CO2 or nitrous oxide.

In case you're really curious, here's some good bathroom reading:

http://www.praxair.com/~/media/praxairus/Documents/Specification%20Sheets%20and%20Brochures/Gases/Oxygen/Oxygen%20O2%20Spec%20Sheet%20SS%20P4638.pdf?la=en

And no, <0.1 ppm THC doesn't mean what you think.

Regards,
Mike

Purity is rated at the air-separation site so all of them are very pure as far as O2 content. The real difference (other than the 9s) is the handling, or 'chain-of-custody'. Welding cylinders are not cleaned like medical-grade cylinders. They are also filled differently, etc. As stated previously in this thread, organisms don't play well in a pure O2 environment. So, really, the purity rating is not as important as the handling.

There may be federal, state, municipal, etc, codes that require medical grade. May be a good idea to contact the health department.

[grnis]

We don't have one.

We have an oil-free compressor that supplies the brewhouse. A sterile filter connected just before our wort aeration port, a flow meter and a control valve.

[ziggy13]

This is probably more information than anyone needs to know, but oxygen is sold (at least by Praxaire) by the number of "nines". So grade "6" is 6 nines pure: 99.9999%. I have no idea what the welding supply sells, but most likely it's the lowest grade, which for Praxaire is 2.6. That's 99.6%. There are specialty grades for semiconductor use, but you won't find these at your welding supply. I used to work for a company that made UHP gas purifiers, and we bought literally truckloads of cyrogenic oxygen from Praxaire, which was 99.993%.

99.6% is a curious number, because that's what the minimum purity is for USP grade Oxygen. So, AFAIK, all oxygen in the US is at least USP grade (medical grade), because it's not cost effective to have bulk storage for multiple grades. The main difference is how the cylinder is filled and labeled. But the oxygen is the same for both "technical" and "medical" grade.

Short answer (IMHO): Oxygen is Oxygen, as far as brewers are concerned. Put a sterile filter inline, and don't worry about trace amounts of argon, CO2 or nitrous oxide.

In case you're really curious, here's some good bathroom reading:

http://www.praxair.com/~/media/praxairus/Documents/Specification%20Sheets%20and%20Brochures/Gases/Oxygen/Oxygen%20O2%20Spec%20Sheet%20SS%20P4638.pdf?la=en

And no, <0.1 ppm THC doesn't mean what you think.

Regards,
Mike

Any suggestions on which sterile filter to buy, and where to buy it from?

[Mike Elliott]

Over-oxygenation is real.

I have a 40ft^3 tank on a 7bbl system and I swap my tank every 3-4 brews. It costs about $13.50 to swap the tank. Initial cost of the tank was about $100. The welding supply company I use is practically next door. I had to find a O2 regulator at a national fire fighter Corp for an additional $50/or so. From what I have read in the yeast book from the brewer's association it is hard to over O2 wort before fermentation. Just my experience so far. Good luck!

Check this forum for threads on overusing O2. The great Dick Murton found sources that imply excessive oxygen can actually stall fermentation and impact attenuation.

We have a 50# cylinder on a 50-bbl brewhouse that lasts for at least 1000 bbls, maybe more. Doesn't take much to get up to 10-12 ppm.

[TGTimm]

We're getting about 800-1,000 bbl/50 lb cylinder. We have two on hand, so one is in use and the other is either getting filled or is back-up. We never run out.

[ChesterBrew]

We have a 3bbl system and a 50lb cylynder we haven't even used yet. We transfer into the fermenter through the sprayball at the top of the tank and all of our fermentations so far have taken off right away without fail. I would say get a small tank to have handy but you may get adequate aeration just through the method I'm describing.