Beer gas conundrum.

As @billandsuz stated earlier, a 85-CO2 and 15 - N2 mix is more than highly unlikely. Remember, CO2 is naturally in a gas-state at ambient pressure, but our CO2 tanks are filled with a liquid solution. As the liquid "boils" the gas starts to expend in the tank until it reaches an equilibrium point (identical to your propane tank). This equilibrium is temp dependent and it tops out around 1000psi.

Commercial nitrogen is typically stored over 2000psi. It is possible to blend the gases of different pressures, this is what the diving industry does every day. But that's done with gaseous state only (typically oxygen and helium and air), no liquids involved. If there was liquid CO2 added to the tank then topped with N2, then the ratio would be constantly changing as the carbon dioxide converts to gas and re-fills the headspace.

Would be interested in the actual pressure of the contents. If you're game, throw a CO2 reg on it and see what the pressure reads. My guess is it would have to be all gas and that would limit the pressure to 1000'ish psi at most, which means it will kick a lot sooner than your normal CO2-only tank at 1000psi (disregard my previous post of high quantity). There are techniques to boost pressures above cylinder-storage pressures, but the equipment to do that is not normally available to a bunch of beer-pushers.

All this discussion is probably 100x more than you originally wanted to know, but why waste a chance to tinker around with compressed gas?

 

Thanks.
This bit makes explaining it visual and easy to grasp.
Cheers

Edit;
Though I doubt my citing of Vukalovich and Altunin's seminal 1965 study will add to the conversation.

 

...before you attach the reg, weigh the tank. Somewhere on the neck will be the tare weight (cylinder weight empty). It will be stamped, some like TW 25.3 . . . the difference will be weight of contents.

EDIT: you attach'ed the reg before I re-posted . . . but you get my drift.

re-EDIT: what is room temp for your tank?

re-re-EDIT: just noticed tank in background has a TW of 7.7 . . . 5 lb'er?

 

I think you'll find that it weighs 25.5 lbs at any temperature. (Unmeasurable relativistic effects aside.) I don't think I've ever seen a CO2 cylinder without a tare weight somewhere on it. Odd.

 

Safe to say there is no liquid CO2 in the tank. 1000+psi at 66 indicates something else has been added to the tank which explains his claim of some nitrogen. If this was conventional CO2 you would have ~800psi at 66. All tanks have a TW, but sometimes they are unreadable or unfindable.

I sure hope your friend is a great beer drinking buddy . . . cause his CO2 prowess is lacking. In addition to giving you a tank with an unusable mix, it is almost empty before you hook it up. With 1000psi of gas only it's going to kick PDF (can still be used for purging). But it gets worse: The master valve in the photo is not seated correctly . . . there is tape on the exposed threads. These threads are not tapered, rather like a machine screw where a nut will spin until it gets to the end. It's called a National Gas Outlet (NGO) and the seal is made with an o-ring. The base of the master valve should be screwed in until it touches the neck of the cylinder. A lip will compress the o-ring and that's what makes the seal. There is a torque setting, but most people just go till it stops, then a touch more. The threads should all be inside the neck and tape is not used. This is identical to how you attach reg to valve outlet: You have an embedded o-ring or nylon disc that is compressed by the locking nut. This locking nut spins all the way until the o-ring mates with the valve outlet, then a little more to make the seal. You are sealing metal-to-metal with an o-ring, no tape involved.

On your gauge with the single gas outlet you have exposed threads with tape on the tapered connection (NPT) at base of gauge and nothing on the threads for the swivel nut attachment as it is not tapered, rather male flare (MFL). Seal here is made by compressing threads wrapped in tape for the upper and pretty sure you have a nylon insert at the base of the barb that seals under compression with the outlet. This is all correct and industry standard. I don't see any tape on the threads of your wye . . . this is tapered (NPT) at inlet and outlet and should be taped. I'm guessing it is taped on the inside (compressed threads) as it would have trouble sealing otherwise. Nice oetikers BTW.

Probably up to 200x more than you really wanted to know. Would be nice if all posters on this thread would drop in on Home Bar and leave a comment (anywhere) . . . we are dying for activity over there.

 

We like to nerd out.

My experience has been that any dealer in bottle gas will take any cylinder for exchange. Like bbq propane. They don't care too much where the cylinder originated, at least not any of the dealers I use.

One reason we always tell people who are buying a kegerator to not opt for a new CO2 cylinder. It ships empty and shiny. Then you exchange it for a full old one in stock. A lot of gas retailers do not actually do the re-fill at the site but rather have the cylinders shipped and held in the warehouse out back, so they could not refill the new cylinder even if you asked.

I am trying to get to 1,000x more info then necessary.

Cheers