Filling my own 5lb CO2 tanks

Does anyone know the technique and hardware needed to fill a smaller tank of CO2 from a larger one? I have two smaller kegerators that use 5lb CO2 tanks and I just bought a larger 20lb tank for a bigger freezer. I can get the tanks filled for $12.50 each plus 50 cents a pound. So 5lb tanks are $15, but 20lb tanks are only $22.50. I'd like to fill the little ones from the bigger one and save the $12.50 every time.

 

yep, build a proper line from bottleto bottle. get a good scale. Hook the big bottle to the little bottle. Put the little bottle on the scale. Tip the big bottle upside down. make a note of the weight. Open the valve on the little bottle, open the valve on the big bottle. Put 5 pounds of CO2 (by weight on the scale) into the little bottle. Close the valve on the little bottle, then the big bottle. It will help tremendously to freeze the 5 pound bottle before you fill it. You may not be able to get a complete fill all of the time, but you'll get enough in there to make it worth your while.

 

It's pretty straightforward. You'll need the followings items:

1.) Fill Station


2.) CGA320 Adapter


3.) 1/4" x 1/8" Female Coupling (to connect the CGA320 adapter)


4.) Fill Station Muffler (recommend)


The parts can be purchased on ebay and at your local hardware store (or McMaster).

You'll need a stand to hold the 20lb tank upside down. This ensures you're filling the destination tank with liquid CO2. You'll also need to freeze the destination tank prior to filling, or you can purge the destination tank with a couple ounces of CO2 to quickly chill it.

Like the other poster stated, be sure to get an accurate scale and fill it ~90% to weight. If you overfill the tank, it will likely rupture the safety disc after it warms up.

 

Thanks for the information! I have the stuff ordered from Ebay. To be sure, the fill station was set up for paint ball tanks right? The fill station looks like two female fittings and if I put the CGA320 adapter on the 1/8 to 1/4 female, I won't have a male for the fill station. What is the paint ball tank thread?

Also, wouldn't it be the same to weigh the 5lb tank until it shows 4.5 in it? Then I wouldn't need an upside down support scale.

 

When I fill paintball tanks (20oz, etc.), I use an adapter. I just screw the adapter into the CGA320 when necessary.

The destination tank (e.g., 5lb) should be right side up or on it's side. The source tank (e.g., 20lb) should be upside down. So ya, you either need someone to hold the source tank or build a simple support frame.

 

Ok.. I have everything in the pictures and I don't mean to be dense but..

In picture 1.) of the fill station, one side goes on the CO2 tank, what is the thread of the other end? Is it a female 3/8" NPT? Do you need a nipple?

 

It's just a purge valve port for chilling/purging tanks. So, no, you don't have to attach anything to it. But, I do recommend #4 (Fill Station Muffler) as purging tanks can be quite loud when you suddenly release the CO2.

 

Thanks.. but I meant the piece with the knurled knob on it. I'm assuming that is the fill valve. I'm hoping it's a 3/8" NPT female that I can put a nipple on, then the adapter to 1/4" and then on to the CGA320 for the tank to be filled. I'll just take it to HD and check it out. Thanks so much for the reply's and answers to my incessant questions about this thing.

 

It should be an 1/8" male (depending on which fill station you bought). See #3 - 1/4" x 1/8" Female Coupling (to connect the CGA320 adapter).

 

Wow, mine ended up being ~1/2" female, at least it threads in OK but leaks a bit. I just used a reducing bushing to go to the 3/8" CGA320 pipe. I filled a tank, but leaks were shooting out around the paint ball adapter. It was a bit scary. A couple thousand pounds of pressure makes me jumpy.

 

Ya, that fitting is a bit oversized. 5 wraps of teflon tape and you should be fine for the 1/2" fitting.

BTW, CO2 is about 800 PSI at room temperature, but ya, definitely dangerous! Be careful and wear gloves/eye protection just in case something goes horribly wrong! :cross:

 

Next time you fill your 20# tank, swap it out for one with a dip tube. that way you won't have to flip the big tank over. It's much safer.

There's lots of videos out there around showing how to refill a paintball tank. It's the same principle for the 5# CO2.

 

If you build a small stand to invert the tank, it's actually safer than a free-standing upright tank. It's difficult to topple a stand (wider base) but pretty easy to topple a free-standing tank, at least that's my experience.

As far as the dip tube, the places in my town that stock dip tube tanks are more expensive than the welding shops. So, there is an economic advantage, at least for me.

 

Looking to build my own fill station and was wondering about the steel braid used in the prebuilt ones on ebay. Anyone know where I can get the high pressure hoses necessary to handle the temps and pressures of a CO2 tank?

Is it just cheaper and easier to buy the premade stations?

Thanks!

 

Got mine made from high pressure hyd/pneu hose rated at 5800psi as I needed a line for my Nitro tank as well, which is 3000psi they cut me a good deal as I only needed a small line and they had some cut pieces under 2 feet had 4 lines made for 28 bucks had 1/4 flare fitting ends.

 

I had an extra regulator that I had parted out so I thought I would be frugal and use the CGA320 adapter that was on it. I received the paintball adapter and 1/4 to 1/8 adapter in the mail. I was happy to get started taking the CGA320 adapter off my old regulator and put this apparatus together . After a hard tug, then looking at the threads, I realized it had LH threads. FML. Now I've got to wait another week to get the new adapter from eBay. Should have checked out what I had before I started ordering, or in this case, not ordering.

 

This group did not tell you to unscrew and discard the knurled nut assembly from the hose. I believe the threads on the end of the hose are 1/8 npt you would then connect the cga320 nipple to the hose with the appropriate bell reducer.
better luck....

also I do not believe you will be able to refill your 5lb tanks more then 2 times with a 20lb tank.

 

cheaper would be to use 2 - cga320s nipple together

 

Hope you still check in here, Lamarguy! What should be on the other end of the CGA320 adaptor? does it go from CO2 tank to sodastream fitting? Paintball? Somethingelse? I want to make sure I order the right fitting, since I can't get this at the local hardware store!

 

https://www.amazon.com/dp/B00NU9NDI4/?tag=skimlinks_replacement-20

 

That's by far the easiest, and if I had it to do over again, I might go with that one, but it's $65 instead of $25 for one that goes to a paintball tank.

 

For anyone that wants to do this, you will need to take the paintball or sodastream connector off first. Mine was so tight that the wrench actually started to smooth over the nut - a little penetrating oil overnight did the trick, and it finally came off. The CGA320 adapter I had to pick up at a welding shop, and Lowes actually carried the adapters I needed, although the guy didn't think they did. It ends ups going from the fill station to a 1/8"x1/4" adapter, to the CGA320. $25 for the fill station, $9 for the CGA 320, $5 I think for the adapter, total cost about $40. Savings after going through one 50lb tank, about $130.