Beer gas conundrum.

This seems like an odd thing to do, given that CO2 cylinders have different connection hardware than nitrogen (blend) cylinders.

A nitrogen regulator wouldn't fit a CO2 cylinder anyway.

75/25 is 75% nitrogen and 25% CO2. If your cylinder has 85% CO2 and 15% nitrogen, that's way different. I'm not sure I've ever heard of anyone using that mix.

Therefor: @billandsuz

 

Thanks @VikeMan

I do not think you have 85% CO2. That is not possible. Not as far as I know. You can get 25%CO2 75% N easily, that is the Guinness blend. But increasing the CO2 and decreasing the N is just not possible for a variety of reasons. It gets harder to fill a blend as the CO2 increases. Suffice to say I'm not a chemist and do not work for Airgas but I do know, you don't have 85% CO2.

So let us assume you have 15% CO2. That is not useful. It will push beer alright but you don't want it. Unless you have over 100 feet of barrier tube trunk line. Maybe 300 feet to be honest. 15% CO2 (or 85% CO2 even) is going to get you flat beer as the keg empties.


Is this a Male thread tank? Dump the gas.... outside!... and refill. Or trade it in for a full 20# CO2. With a Male thread.

Don't vent inside, the gas is not poison but it will create an oxygen deficient environment, and you will pass out very quickly. Really. Asphyxiation is a terrible way to go.

And you got a 20 pounder out of it. Cool.

Cheers

 

I appreciate this reference.

 

Yep. That looks like a CO2 cylinder. A nitrogen cylinder looks like...

Note the female threads (which you can't see here because they are inside) vs the CO2 cylinder's male threads.

 

If it does take a CO2 regulator it is indeed a CGA320 valve for carbon dioxide.

Industry standard procedure is to vent and refill anything that falls into the WTF category. Even when the maximum consequence is a messed up keg of beer, I wouldn't take the chance.

Interestingly, the Compressed Gas Association(CGA)* has some pretty decent standards for regulating the industry and uses a common sense approach to prevent mixing the wrong regulator to an inappropriate gas. Lots of gas'es out there, and they each have a difference valve with different inlet/outlet dimensions. For example my scuba (air) tank looks just like my CO2 tank, but the threaded inlet to the neck of the cylinder are different, making it impossible to install the wrong valve and attach the wrong reg. This is almost idiot proof . . . I'm sure it's been done, but it would require considerable effort to attach something like an oxygen reg to a propane tank.

Maybe TMI, but here's a chart showing many of the common valves. If you dig around you can find the exact dimensions of inlet/outlet size for each numbered valve:

There is an adapter available to allow a CO2 reg to mate with a nitrogen valve, this is possible because the gases are similar in inertness and stored pressure.

*Untouched by gov'ment regulations.

 

CO2 bottles are sometimes filled with nitrogen, or perhaps more accurately N gas may be put into a bottle with a CO2 valve body and vice versa. Why I do not know. It is not a good idea.
That is why you can buy this N to CO2 adapter.

or this CO2 to N adapter

So you can get each gas out if you have the wrong regulator for the tank valve. It is a terrible idea IMO.

If you should manage to put a typical CO2 regulator on a tank of nitrogen you will learn that CO2 regulators are not as durable as N regulators. The CO2 bonnet is (usually) plastic and the N will be metal. The body of cheaper CO2 regulators is plastic as well. An all metal regulator is a quick quality check. The springs are also less robust because the inlet of a CO2 is ~800 psi and the inlet of N is ~2800 psi. It is a bit harder to fine dial pressure on an N regulator as a result.

When these gas bottles get out in the field we can be certain plenty of people assume if the regulator fits it must be the right gas.

Basically, use the right regulator for the tank.
Cheers

 

Sorry to hijack the thread, but it seems to have mostly run its course...

Speaking of nitrogen, anyone (@billandsuz) know of a good tutorial on balancing a 75/25 setup that has a stout faucet restrictor plate? I'm particularly interested in how the plate enters the calculus, if it does.

 

I think that's a great idea. Since nitrogen or CO2 can be used to purge kegs (and other equipment), it seems like a mix should do the job just as well.

ETA: But see @billandsuz's post about CO2 regulators not being as sturdy as Nitrogen regulators.

 

Sounds like a good idea.
CO2 is really cheap. But if you are anywhere near as cheap as I am then free is even better.

No tutorial I know of except that the applied pressure is high enough to overcome system restriction. 5, 6, 7 feet of choker is not a problem. The applied pressure is 30 to 33 psi, and that is on direct draw or 75' glycol systems. When adding a nitro line, it is simply put in place of the standard beer line with the gas and faucet being the only changes. So calculate balance it as if it were a regular beer.

It is supposed to be foamy and there is a known delay between pouring and serving. This is quite different than the typical ale/lager where the bartender wants to fill the glass quickly, with minimal foam and then turn around and present a pint with a perfect collar of foam. That system needs to have the restriction pretty well dialed in, especially because small changes in pressure can have a big impact on vols. Restriction is fixed; too much or too little is not easily changed. Homebrewers of course, we like to have a 6' line, a 6' 10" line etc. But that is not possible anywhere else.

I have no idea about the restriction of the restrictor plate other than "a lot". Probably 25 psi or more. Just guessing. With 30 psi applied the beer pours slow, less than industry benchmark 8 second pint.

Micromatic, as much as I am not a fan, probably has some data hidden on their website.
And they have a few websites too, not just the USA .com Try https://www.micro-matic.co.uk/
Look through the other countries too, and Google translate. Lot's of data at MM web pages.

Cheers

 

I am not a nitrogen'er, although I think every atmosphere should have some. But the overall way to pressure-balance a nitrogen system is straightforward. The sum of the partial pressure's of gas in a system is equal to the total pressure, which is from our old friend Dalton and his way of stating the Law. In practice, take the fractional percentage of each gas times the total pressure to compute the partial pressures.

Example: With a 75/25 gas set at 30 psi you would have the partial pressure of nitrogen at 22.5psi (30psi x .75) and CO2 at 7.5psi (30psi x .25) . . . adding the sums gives you the total of 30. In the real world you want to know where to set the beer-gas pressure to keep a constant volume of CO2 in your Guinness. You need a carbon dioxide pressure to maintain the correct carb-level. Just work the problem in reverse: say you want a CO2 partial pressure of 10psi, you'd need 40psi of total pressure (10 ÷ .25). So 75/25 gas at 40psi is the equivalent of straight CO2 at 10psi. This same principle is used to balance long draw systems that have a nitro generator hot wired into the CO2 supply (enough pressure to push it and just enough CO2 to keep it carb'eb correctly).

Physically balancing a nitro system once the pressure is set is not my area (I believe this is what you're after). This is where a restrictor plate has an input, just like line length and vertical rise. If I understand @billandsuz correctly, if nitro faucets are being fed at 30'ish psi and only 6' of line then resistance of the plate is a whopping big number. If that is true, you could work the problem backwards, i.e. how much line-length to reduce 30'ish to pour like a normal short line, the difference is the plate resistance. But will defer to any true nitro-balancers. When I built my keezer I had the fantasy of a nitro faucet . . . until I learned what it involved.

For @Soneast , check the hydro date on neck/shoulder of tank . . . it's good for 5 years past the stamped date (if you want a commercial fill). Using the current gas as a purge gas is a great idea. Just remember, you'll be able to hit a ton of tanks. Might want to look for alternate uses like the headspace in a secondary, jars of hops, maybe purge the neighbor's cat.

 

etc..

Cool. I get partial pressures, etc. Was just looking for restrictor plate numbers. Apparently, the plate makes up the difference between ~10 PSI and ~35 PSI. Good enough as a starting point.

 

Great info. Thanks!

At some point in the past I inherited a high-end, stainless-steel Matheson regulator (had been used for Argon), that I now use -- with the second adaptor you showed -- for my kegging system. It has worked great for me, although the pressure to the kegs does drift around a bit at times. Had I had to pay for this regulator, it would by far be the most expensive piece of equipement in my brewhouse!

Cheers!

 

Photo?

 

Here's a link that might work: https://flic.kr/p/2ijYcL2

 

@Soneast did you ever just ask the guy what he meant by 85/15?