Using Scuba Tank For Oxygen.

[Hogan]

My brother in law gave me a 63 cf aluminium scuba diving tank when I told him I was looking to use O2 for yeast growth. It has not been tested for a few years and I am aware that it will have to be retested and also professionally cleaned for O2 use.


Questions:

Any brewers using dive tanks for O2 ?

Are the dive tank threads compatible with regulators used for medical application?- (I can get an O2 reg and flow meter through a vet).

If the threads are not compatible what regulator could I use?

Will I be able to get it filled?



Cheers, Hoges.

 

[mika]

Don't think anyone's going to want to fill it with 02. Dive shops are usually just pumping air in there and I'm pretty sure it's at much lower pressures than what BOC would fill an O2 cylinder to.
The fitting I've seen on the top of Dive tanks doesn't resemble anything regulator like, but then presumably that can be screwed off and you might be able to get a reg adaptor to screw on. Presumably the bottle would just have a Female/male thread of fairly standard origins and then the adaptor into that before screwing the reg on.

 

[[email protected]]

You will be able to fill it at a dive store, only with air (22% O2). However it needs to be hydro tested annualy and you will need a rec diving license. They will check these things.

I think the threads on an pure O2 tanks are different. Diving regs are expensive and they will deliver too much air.

I wouldn't bother, rocking a fermenter will give close to 100% aeration in about 5 mins, or a cheap aquarium pump will do the trick.

 

[mwd]

No dive tanks are different the valve is connected to the tank. The scuba regulator clamps onto the tank pillar with a collar not a threaded connection.

Not sure it would be feasible to replace the tank valve with an industrial type regulator threaded adapter.

 

[Hogan]

Don't think anyone's going to want to fill it with 02. Dive shops are usually just pumping air in there and I'm pretty sure it's at much lower pressures than what BOC would fill an O2 cylinder to.
The fitting I've seen on the top of Dive tanks doesn't resemble anything regulator like, but then presumably that can be screwed off and you might be able to get a reg adaptor to screw on. Presumably the bottle would just have a Female/male thread of fairly standard origins and then the adaptor into that before screwing the reg on.

Would not be looking to have it filled at a dive shop. The valve is a CIG but is specifically for dive use so it would have to be replaced.

You will be able to fill it at a dive store, only with air (22% O2). However it needs to be hydro tested annualy and you will need a rec diving license. They will check these things.

I think the threads on an pure O2 tanks are different. Diving regs are expensive and they will deliver too much air.

I wouldn't bother, rocking a fermenter will give close to 100% aeration in about 5 mins, or a cheap aquarium pump will do the trick.

Looking for 99% O2 not 22%. Will need a hydro to start but that size bottle of O2 will last me for yonks. Don't want a dive reg I want an O2 reg. Have read that the valve threads may not be compatible. Currently using an aquarium pump and air stone at the moment but don't like the foam stripping my head forming proteins.


Thanks for your input.

Cheers, Hoges.

 

[[email protected]]

There are 2 types of scuba tank adaptors, DIN and Yoke, most Australian are yoke, where the regulator is pushed onto the tank by a clamp. The DIN style is a screw thread, I'm not sure what size but you might be able to fit something to it. However chances are you have a yoke tank. You can replace a yoke adaptor with a DIN fairly easily. But really I wouldn't bother, there will be far cheaper options. SCUBA stuff is expensive.

The most oxygen you can get from dive stores is NITROX, this is upto 50% O2 but you need a special tank for it. Not sure where you would get this filled but your best bet is to call a commercial diving shop. And I think they use a different te of tank for this.

 

[Spork]

Just remember kiddies - don't drink and dive.

 

[BjornJ]

I haven't dived for years but from memory the screw in style ones are 300 bar and the "yoke" are 200 bars.
You will not get it filled with oxygen but if using air you will get a similar (same?) effect as you do today with the aquarium pump and airstone. As you would still be pumping air through the wort, just at a different pressure.

For oxygen you would need a O2 cylinder and a O2 regulator, most dive schools and a lot of dive boats have them for emergency treatment while bringing someone ashore after an accident. No idea what it would cost though.

 

[abyss]

Gday Hoges I dont know much about brewing but I have dived commercialy for most of my working life and I reckon you should just use a proper O2 bottle if you need it. And NEVER use any lubricant on the threads as it may EXPLODE !

 

[woodwormm]

would it not be easier to just get an oxygen bottle from an oxy-acetylene welding setup?

then you can get filled at any of the gas suppliers....

... i'm probably missing something here on the grade of oxygen in a welding tank versus the medical grade you want to get... oh and yes i do get the bit where you've scored a free bottle, but sometimes it costs a lot more adapting and sourcing stuff to suit your freebie than just getting the real thing in the first place (from experience :icon_cheers: )

 

[hydroboy]

Are you serious? Oxygen is some of the most dangerous sh1t ever to be ducking around with at high pressures. Don't try and put it into anything that isn't oxy clean. Regulators, tanks, anything. Oxygen + Pressure + Oil/Grease/Contaminaints/particles can = fire/explosion

This gives you an idea of what might go wrong

 

[Filby]

63cu/ft ali will need to be hydro tested and o2 cleaned as you know. From there it will be stickered to indicate the date of cleaning and stamped to indicate date of hydro testing (and you have one year before you need to do it again). From there you can get it filled by any decent scuba store to 50% O2 (some will ask you for an nitrox certification..). For yoke valves you can only fill to 206bar which is likely the valve you have (for interests sake, standard DIN are rated to 225bar fills, though there are now 300bar tanks/valves but good luck trying to find someone who will actually fill it to that pressure). Oh and most older Ali's are only rated at 200bar because they have a tendency to crack and exploded..demolishing the building and person they were near in the process.
As far as regulators go, none of the oxygen providing regulators fit into either a yoke or DIN fitting on a scuba reg so your best bet is a normal scuba reg adapted to whatever your setup is.
Also, CIG/BOC wont fill scuba tanks as the inherent dangers of filling an unknown tank with pure O2.....booom!

 

[Wolfy]

I wouldn't bother, rocking a fermenter will give close to 100% aeration in about 5 mins, or a cheap aquarium pump will do the trick.

I presume your information on the O2 bottles and regs is correct, but this quoted info is not.

Shaking the fermentor for 5 mins results in about 2.71 ppm O2.
60seconds of pure O2 (@ 1L/min, .5micron stone) results in about 9.20 ppm O2.

That is a huge difference given that the 'ideal' amount of O2 for most beer fermentation is 8 to 10 ppm.

About the best you can do either by shaking our using an airpump/stone is around 8 ppm O2, but that requires extensive vigorous shaking or using an air-stone for a long period, rocking the fermentor for 5 mins does not come close to that.

(Information from 'Yeast, The practical Guide to Beer Fermentation, C. White, J. Zainasheff, page 76-79)

 

[Hogan]

Thanks to all for your responses. Just the sort of info I needed to make an informed decision - and I have made a decision that I won't be further contemplating the use of this tank for O2.


Cheers, Hoges.