O2 tank questions....

You should have no trouble exchanging a cylinder at your local vendor. Just keep in mind that oxygen is a fairly serious gas when it is kept under pressure. For example, the cylinder and everything else must be kept clean and free of grease or anything flammable. All of the fittings need to be compatible with oxygen. Oxygen, it's a strong oxidizer and all that stuff after all. Your supplier will gladly sell you everything you need.

For wort aeration unfortunately there is no fool proof way to determine the saturation of oxygen into wort without the use of an expensive dissolved oxygen (D.O.) meter. There are too many variables. Wort density. Temperature. Flow rate. The pore size of the sintered stone. You can hit the wort hard and watch the oxygen froth like mad, but all that bubbling is really indicative of gas not dissolving into the wort. Low and slow, for about 1 minute in a 5 gallon batch is plenty. I have experimented with quality D.O. meters and found up to 20 ppm can be obtained but it quickly settles at much less. A cold wort will hold the gas much better too. You can over oxygenate and cause some funky yeast activity but that doesn't seem like a problem high on the list of headaches homebrewers experience. Oxygen saturated wort isn't going to fix unhealthy yeast. But sufficient oxygen will certainly help. Maybe not enough of us are blasting with pure oxygen to really know.

That tank you have, if I had to guess, will last for a long time. Oxygen gas is stored as a gas not a liquid, but even still there is a lot of gas in one of those tanks. The little Burnz O Matic red tanks are good for around four or five batches in my brewery if i had to guess..
That's my experience.
Cheers.

 

BrewCipher assumes a flow rate of 1 Liter per Minute. (It's in the pop-up cell comment and in the user guide.)

 

Your class D tank holds 410 liters of oxygen when filled to 2000 psi (normal O2 fill pressure). I have it's big brother (Class E, 820 liters) and it lasts a long time. I brew a lot, and always use oxygen for starter and wort in primary, typically one liter in each. Do the math, I'm into the fifth year on mine and there's a lot left.

Everything billandsuz says is correct, but to expand: Yeast publishes some criteria on amount of O2 vs. wort OG , , , basically it amounts to 1L for a mid-OG 5 gallon batch. Use a .5 micron stone, set your flow to 1L/min and rip it for a minute and you'll be fine. I do the same for my starters. Normal oxygen level in water is 8 ppm. You will exceed that, so the extra molecules will immediately start to drift out of solution and into the headspace. But, you are replacing air in the headspace with O2. As the yeasties consume the dissolved oxygen, the headspace oxygen will diffuse back into the liquid (keeps our little friends happy) till it's gone. That's why I use a full 1 liter for a starter. I've never had my yeast complain about being over-oxygenated. If you don't have a reg they are on Amazon/eBay, should be no more than twenty bucks. Flow rates are all over the place, you want 1L/min which they all have. The higher flow rates (10+L/min) are for sick people.

Refills are all over the place and depends on your area. Florida does not regulate it, you can buy it like it's a box of Wheaties. Other states classify it as a drug and you must have a 'script just like it was oxcy. If filling commercially the tank must be in hydro. Check your date on the green band, it will have month - space - year. Looks like 11 19 and expires in 5 years. Price is all over the place on new inspection, in my area it's ~$35. I have a friend with a 3-tier'ed oxygen system and he lets me refill for a six-pack of Miller Lite and we don't worry about the regs. You want aviators oxygen, but welders oxygen is identical except for how it's labeled. Avoid medical oxygen (which is also identical but costs more).

It is safe to handle with the smallest amount of common sense. Do not store in your fireplace and only shoot at it if you are under attack by a very large shark. I keep mine in the utility room and just make a point that is doesn't fall over, mostly to protect the floor.

For others interested, you can find Class E's at many flea markets or garage sales for $25-30 with reg attached. I think they are from people who have died but I never bring that up. Nothing wrong with buying used, just check the hydro date. They are all over eBay but shipping tends to be a mite high.

 

I will admit it would be fun to carry to shooting range (long distance) and shoot it with a scoped rifle.

A few other tidbits: You still see some steel tanks (mostly used) at a good price but try to avoid. Any significant amount of surface rust will condemn it on next inspection. Even alum will tend to pit on the surface when kept in a harsh environment . . . good to wipe it down regularly. Never touch the sintered stone with your fingers (or anyone else's). Oh yeah, don't let auto-correct send you in search of "spinchter" stone . . . you'll be disappointed.

 

I’ve been using these little Benzomatic tanks and they don’t last long at all... so expensive for constant new tanks.

If one were to use 1-2L per batch of beer on a 410L, you are looking at getting between 200-410 batches of beer out of one tank... how much does a fill cost?

I’m debating going in on a tank & regulator. Trying to see what my ROI will be since I only get about 2-3 uses per Benzomatic tank at about $12 per tank ($4-$6 per beer, ouch!).

What’s the cost of a fill?

 

Don't know exactly because I've never paid for it. My friend has a three-bank oxygen system and lets me fill for free. He pays 36 bucks for a tall cylinder (see photo below) so there isn't much cost involved. In Florida you normally deal with an industrial gas supplier (think welding supplies). The only thing tricky is you need a 3-pin fill system (CGA 870 valve) and the big welding tanks have a threaded connector (CGA 540) . . . some suppliers have both, some don't.

In regards to tanks: a class D (410L) will certainly do the job but you see many more class E's (which are 680L, disregard my previous number), plus it only costs a sliver more than the small guy. The E is what you see strapped to the back of a wheelchair in just about every emergency room in the country. Often time they are attached to a "rolling carrier" . . . if you see one of these at a flea market it's probably from someone who has deceased:


Here's tank sizes available on the market:

You want the E or smaller which any of the slim line regs will fit (CGA 870 valve). You'll probably never see 2200 psi, more likely a little below 2000 which is of no consequence. My E has been used for over 7 years and I'm just now down to 400 psi. I have another flea market E ($20) in reserve when the current one kicks. You will see these all over Craigslist and eBay and Amazon (new) with prices all over the board. Final caveat: Gas suppliers seem to enjoy preying on the uninitiated, i.e. if you look clueless and prosperous they tend to charge more. Best to wear a dirty pair of jeans and if you have a nice car park around the block.

 

Did some sleuthing around about oxygen tank fills (in Florida). Here is a class jumbo D from a dive boat, capacity is 640 liters and it's pretty light weight, can sling around with one hand. Cost to fill (at dive shop) was $12:


Here is hydro date on green band. Date is 12 18 (Dec 2018), the large C between numbers is manufacturer (Catalina). Tank is good through Dec/23, then look for new date that should be stamped into metal near the same location. On really old tanks it may be hard to read:


Here is valve (GCA 870). Large opening is for the gas, the two small opening are where the pins on the reg lock in. This is unique to oxygen tanks, a reg for air or argon or nitrous oxide or whatever will not fit. The nut on top opens the valve by a small wrench usually attached to reg.


The jumbo D is somewhat of a specialty tank, it costs much more than a regular D (410L) and the more common E (680L).

 

Technically a full fill is 2200psi but you almost never really get that, filling to 2000 or even less is what you see. At 1700 you have 17/22ths of 410 liters (whatever that is). Pressure changes from temp can by ignored. You want to store the tank with master valve off and reg at zero. Think of it just like your propane tank. You have two valves that control the gas flow . . . close them both. You only need one to work properly but no effort to use 'em both. I close master valve first and let pressure bleed to zero (into the wort), then zero-out flow control.

Don't want to scare you, but I put an oxygen analyzer on one of my flea market buys and it read 85% oxygen. Fairly sure the other 15% was nitrogen (from air) but no way to know for sure. I vented and re-filled just because it was easy to do.

 

Are you making 50 gal batches. I can get at least 10 batches with one of those red tanks.

 

From my experience, O2 analyzers are some of the most difficult meters to maintain. They need constant care and attention, more than most other portable gas analyzers.

Check it against ambient as well as a known concentration. It may very well be near impossible to get a true 100% oxygen reading.
This is just my guess though.
Cheers

 

10-15 gallon batches.

Perhaps I’ve been opening it up too much. I have dialed it back this last batch to where I can just barely see the surface of the beer bubble up when stone is delivering O2.

 

Yea that's tough if you use stainless.I use the speidel so i just place the stone against the outer wall to see how hard the bubbles are coming out.

 

All interesting stuff.. I need to move away from those benzomatic cylinders as well..

Question I have is more about flow rate. I know 1L/m is often quoted but it’s interesting to see the Lodo guys talk about aerating for 4 minutes at .25L/m and clearly they have the DO meter to measure everything. Is the o2 more likely to stay in solution at lower flow rates? Makes sense that it would.

Anyone here have an in-line o2 setup? Like the big guys. Contemplating buying one when I step up to my larger system here in the next few months.