Refilling a 5 pound CO2 tank

[redrocker652002]

More just curious at this point, but I was thinking of something tonight. I have a 5 pound CO2 tank that fits nicely in my kegerator. I have not really charted how often I fill it, so I could be really just wasting my time and yours. Anyway, I was thinking of buying a used 20 pound tank to use as my filler tank. I am curious how difficult it is to fill the 5 pound tank with a 20 pound? I think in the haul of stuff I have a hose with two ends on it that will fit the two tanks. Is it as simple as hooking them up, opening the valves and let the smaller one fill from the bigger one? Seems too simple to be true, but if that is the case, maybe a used tank to keep as my filler might be a good idea? Thoughts?

 

[FloppyKnockers]

It is as simple as it sounds.
Chill the empty 5 lb tank.
Warm the 20 lb to room temp (or an hour in the sun is better).
Attach the fill hose to the 20 lb and flip the tank upside down.
Connect the 5 lb (while it sits on a scale)
Open the 20 lb valve
Open the hose bleeder valve until liquid comes out, then close.
Crack the 5 lb valve until no more than 5 lbs has been transferred.
Disconnect in opposite order.

Be safe. Wear gloves, goggles, sleeves, and engage safety squints.

 

[day_trippr]

...and don't expect to literally "fill" anything. Towards the end of the 20 lb fill I might get as little as 1.5 pounds into an empty and chilled 5 lb tank. But even that is ok with me...

Cheers!

 

[Agent]

You can even shave a few of @FloppyKnockers steps down by getting a 20lb CO2 tank with a siphon tube. Then you can get liquid out without inverting the big tank.

Filling 1lb propane cylinders from a 20lb tank is pretty much the same process as well.

 

[redrocker652002]

Good to know, thanks to you both for the info. Now, I am going to see if it is worth it financially. LOL.

 

[sibelman]

without inverting the big tank.

This sounds like a really good idea, as I'm having trouble picturing a safe, stable, upside-down 20-lb tank, especially with a regulator on it.

 

[redrocker652002]

This sounds like a really good idea, as I'm having trouble picturing a safe, stable, upside-down 20-lb tank, especially with a regulator on it.

I was thinking the same thing. Where would one get a tank with that tube in it?

 

[PCABrewing]

Amazon for one. But I'd ask your commercial gas supplier first.
Your LHBS likely wont have them for sale but they would use one to fill your 5lb.

 

[IslandLizard]

I'm having trouble picturing a safe, stable, upside-down 20-lb tank, especially with a regulator on it.

When used to fill other tanks there are no regulators mounted. It's a direct line from supply valve to receiving valve.
But the supply (donor) tank should be inside a safe and stable cradle. Easy to build with a few pieces of wood.

 

[Bobby_M]

No regulator. You need a filling whip or "jumper" setup as the hose will sometimes see over 1000psi. A 20LB siphon tube equipped tank is nice, but then it makes the tank ONLY good for filling. I prefer an aluminum 20 with the handle, since you can steady it upside down on the handle and just use a strap to something more stable.

Expect to only "fill" a 5 pound with about 2 pounds on the regular without going way out of your way. You can chill the receiving tank by putting a 1/2LB of CO2 in it, then vent it all the way down and that will freeze the tank. It will take more that way, but it's a waste of gas. You can put heat on the donor tank, but then it's a little sketchy as you can blow the burst disc if you get greedy.

 

[Whisky River]

I think in the haul of stuff I have a hose with two ends on it that will fit the two tanks. Is it as simple as hooking them up, opening the valves and let the smaller one fill from the bigger one?

You might be able to use your existing hose if its rated for the pressure but if you’re OCD about oxygen pick up in your beer, be aware you will be introducing all the air in the lines into your refilled tank. I think even the cheep $20 refill kits on Amazon include a bleed valve to clear the lines before you fill. Might not be a big concern for you, but just an FYI.

 

[day_trippr]

be aware you will be introducing all the air in the lines into your refilled tank

True, but I just bleed CO2 down the tube before connecting it to the receiving tank - and my transfer line has that valve, but a more complete purge doesn't use it...

Cheers!

 

[whoaru99]

This sounds like a really good idea, as I'm having trouble picturing a safe, stable, upside-down 20-lb tank, especially with a regulator on it.

Most of the point remains, but I don't believe there would be a regulator on it. High pressure transfer.

 

[day_trippr]

^correct^

It's a "valve to valve" transfer...

Cheers!

 

[redrocker652002]

You might be able to use your existing hose if its rated for the pressure but if you’re OCD about oxygen pick up in your beer, be aware you will be introducing all the air in the lines into your refilled tank. I think even the cheep $20 refill kits on Amazon include a bleed valve to clear the lines before you fill. Might not be a big concern for you, but just an FYI.

Thank you for the post. I never really thought about that.

 

[redrocker652002]

When used to fill other tanks there are no regulators mounted. It's a direct line from supply valve to receiving valve.
But the supply (donor) tank should be inside a safe and stable cradle. Easy to build with a few pieces of wood.

Cool. Another DIY project. I dig that part. LOL.

 

[redrocker652002]

Thank you to all who replied. I am going to check into this a bit more and see what Craigslist has available. Sounds like a good way to keep plenty of CO2 on hand, but I am not sure how much I go thru a year. Gonna have to keep tabs on that for sure. I am going to keep tabs on my propane use as well. Good stuff, always learning thanks to all

 

[IslandLizard]

Cool. Another DIY project. I dig that part. LOL.

Or as @Bobby_M said, strap it upside down to a stable object.
A pole, table leg, or such.

 

[sampling6391]

Seems like a straightforward process… The place that fills my 5lb bottles checks the stamped date on my bottles then hooks up a hose, puts my bottle on a scale, vents pressure from my bottle, then refill from their giant tank that has a dip tube.

 

[redrocker652002]

I have looked around Craigslist and found 20lb CO2 bottles for anywhere between 50 to 150 each. The new ones on Amazon run about 160 or so. The jumper line, with the vent setup already built in are about 30 bucks or so. I am going to track and see how long I get out of a 5lb tank. If I go more than 1 or 2 fillups a year it doesn't seem worth it right now. Once I expand into a multi keg setup then we will see. Thanks to all who replied. I was curious about it as I am whenever I get involved in something. LOL.

 

[beren]

I do this. It works well. You do need the special transfer hose and they have a purge valve. Make sure that ends goes to the small tank. To do it the safest, you should have the small tank on a scale so you can make sure you do not overfill it. The tank will have an empty weight stamped on it, find that and add 5 pounds. In the winter I will set the big tank near a heat vent and the small one goes into the chest freezer. Always bring the big tank to the small one because an empty aluminum cylinder warms up pretty quick.

 

[Closet Fermenter]

I have looked around Craigslist and found 20lb CO2 bottles for anywhere between 50 to 150 each. The new ones on Amazon run about 160 or so. The jumper line, with the vent setup already built in are about 30 bucks or so. I am going to track and see how long I get out of a 5lb tank. If I go more than 1 or 2 fillups a year it doesn't seem worth it right now. Once I expand into a multi keg setup then we will see. Thanks to all who replied. I was curious about it as I am whenever I get involved in something. LOL.

For no more than 1-2 fills a year, I would think an extra tank would serve you better. $80 and you can have one on standby, and not need to rush on your refill.
I do refill the small propane bottles from a 20#, but there’s no hose to worry about; it’s a solid brass adapter and the 20# tank is stable on the top handle.
Wouldn’t recommend transporting though:

“Federal regulations (administered by the U.S. Department of Transportation) prohibit transport of refilled “DOT 39” cylinders (of which classification small cylinders fall under). Violate that regulation, you’re liable for a fine of up to $500,000 and five years in prison.”

 

[beren]

I mentioned it in another thread but I think most liquor stores that sell kegs also swap or fill CO2 cylinders.

 

[redrocker652002]

I mentioned it in another thread but I think most liquor stores that sell kegs also swap or fill CO2 cylinders.

I did not know they did CO2. I will check that out.

 

[redrocker652002]

For no more than 1-2 fills a year, I would think an extra tank would serve you better. $80 and you can have one on standby, and not need to rush on your refill.
I do refill the small propane bottles from a 20#, but there’s no hose to worry about; it’s a solid brass adapter and the 20# tank is stable on the top handle.
Wouldn’t recommend transporting though:

“Federal regulations (administered by the U.S. Department of Transportation) prohibit transport of refilled “DOT 39” cylinders (of which classification small cylinders fall under). Violate that regulation, you’re liable for a fine of up to $500,000 and five years in prison.”

I was thinking that too. My local Airgas does not refill but just does a switch, so a second 5lb tank might be a nice addition instead of trying to store a bigger tank Thanks.

 

[beren]

I got a a larger tank because 5lb co2 is like $25, 20lbs is $30. I use a few tanks a year so it adds up

 

[redrocker652002]

I was just checking around, Airgas is the only local place I can find. They charged me, I think, about 60 bucks for a 5lb switch out. Seems a bit steep, but it is the only game in town I think. Gonna do a bit more looking though.

 

[Broken Crow]

+1 on @Closet Fermenter 's suggestion. My LHBS does a tank exchange in 5 & 10lb sizes, so I worked my way up to having 3 10lb tanks; One on my kegerator, one in a milk crate with a 2-way manifold and lines for transfers and cleaning/sanitizing/purging duties, and one on a shelf for whichever runs out first. I will never run out of gas after the shops have closed for a long weekend again!

 

[Closet Fermenter]

I was just checking around, Airgas is the only local place I can find. They charged me, I think, about 60 bucks for a 5lb switch out. Seems a bit steep, but it is the only game in town I think. Gonna do a bit more looking though.

Even the LHBS only charges $19.99; $21.59 with tax! Of course, they have a vested interest in keeping me pushing beer in a mug.

 

[redrocker652002]

Even the LHBS only charges $19.99; $21.59 with tax! Of course, they have a vested interest in keeping me pushing beer in a mug.

I am going to check with my local Morebeer. It is about a 30 minute drive, but if it saves me a few bucks why not.

 

[MaxStout]

If you decide to just swap tanks at the supplier, you'll likely get one with a newer test date on it.

 

[beren]

I was just checking around, Airgas is the only local place I can find. They charged me, I think, about 60 bucks for a 5lb switch out. Seems a bit steep, but it is the only game in town I think. Gonna do a bit more looking though.

Yeah that’s super expensive. There’s no welding shops or Fire extinguisher places? I just double checked. The local welding shop is $19 for 5 pounds and $39 for 20 pounds. No hazmat fees or any other hidden things.

 

[Closet Fermenter]

Yeah that’s super expensive. There’s no welding shops or Fire extinguisher places? I just double checked. The local welding shop is $19 for 5 pounds and $39 for 20 pounds. No hazmat fees or any other hidden things.

Check these guys; supposed to be up your way. I just visited them and had a great experience.

https://www.robertsoxygen.com/locations

 

[Closet Fermenter]

Check these guys; supposed to be up your way. I just visited them and had a great experience.

https://www.robertsoxygen.com/locations

They swapped out an empty 30 year old 10lb steel tank that expired in 2018 that I got free for a brand new, filled 20# aluminum tank, and swapped out a 5# nitrogen tank for $48.15. That was $15 for 5# of nitrogen, and $29 for 20# of CO₂ and tax.

 

[IslandLizard]

I was just checking around, Airgas is the only local place I can find. They charged me, I think, about 60 bucks for a 5lb switch out. Seems a bit steep, but it is the only game in town I think. Gonna do a bit more looking though.

I am going to check with my local Morebeer. It is about a 30 minute drive, but if it saves me a few bucks why not.

Call around first to get pricing, surcharges, etc.
I found swapping 20# tanks to be most economical, as long as you keep an eye on possible leaks. That's where the scale comes in, @bracconiere style.

 

[beren]

They swapped out an empty 30 year old 10lb steel tank that expired in 2018 that I got free for a brand new, filled 20# aluminum tank, and swapped out a 5# nitrogen tank for $48.15. That was $15 for 5# of nitrogen, and $29 for 20# of CO₂ and tax.

Now I’m jealous. Are the tanks branded around the collar? There’s one about 40 miles away from me but I occasionally I am down in that area. I wonder if they would swap a larger nitrogen tank for mine. I wouldn’t mind having a 40 ft.³

 

[whoaru99]

Is there actually 5# of Nitrogen in a 5# cylinder (20cf cyl?), or is it more like 1.5lb actual gas?

 

[beren]

Is there actually 5# of Nitrogen in a 5# cylinder (20cf cyl?), or is it more like 1.5lb actual gas?

It’s not liquid like co2, so it’s measured in Cubic feet. A 5 pound CO2 tank holds 20 ft.³ of nitrogen or beer gas.

https://keengas.com/gases/nitrogen/

 

[mac_1103]

My LHBS swaps tanks - $24/5#; $29/10#; $38/#20. They use the local Roberts Oxygen. Might be a little cheaper to go straight to the source, but bigger tanks are definitely more economical either way.

 

[whoaru99]

It’s not liquid like co2, so it’s measured in Cubic feet. A 5 pound CO2 tank holds 20 ft.³ of nitrogen or beer gas.

https://keengas.com/gases/nitrogen/

Yes, I understand in the case of N it's gas. That's why I'm asking. 5# in gas form would be a lot of gas/volume.

The underlying point is in a earlier post someone said they paid $15 for 5# N and $29 for 20# CO2. They got 20# CO2 but they really didn't get 5# N, they got 20cf N, which may weigh something like 1.5lb, yes?