How to Refill CO2 Tank with Air Compressor: 5 Simple Steps to DIY!

Facing difficulties to know how to refill CO2 tank with air compressor?  Then give this article a read. We’ve explained everything so that you can do it yourself!

Air compressors are used for both home and office areas as they can come in handy in multiple situations. But most of the time, we see users face problems while refilling their CO2 tank with an air compressor.

As a CO2 tank is heavy, so it is pretty challenging to take them to the store every time for refilling. It’s time-consuming, and you’ve to spend a few bucks as well. But to refill this on your own, only an air compressor is needed.

So this article is all about how to refill CO2 tank with air compressor. Besides, we’ll also share some tricks and tips in the latter part. So keep reading…

Also, read How to use Campbell Hausfeld Air Compressor

How to Refill CO2 tank with Air Compressor: DIY

As you already know, refilling CO2 can be tricky. But not anymore if you know the correct ways to do it. Before we head on to the refilling part, we’ll share a few tricks and tips for you to perform the operation smoothly.

Here are the tricks and tips for refilling your CO2 tank-

  • Air compressors that are used in your home and shop are different. For use in an office or shop, you need to go for a large size one. Also, the CMH number should be more as well.
  • While operating the air compressor, you should always keep the influential alcohol and other dangerous items away from it.
  • Handle the CO2 tank carefully, and don’t drop it.
  • Before operating, look for any holes or punctures in the CO2 tank to avoid explosions.
  • Keep away any kind of materials (flammable) that reacts with CO2.
  • Wearing a safety pair of gloves is always appreciated while operating it.

Now heading on to how to refill CO2 tank with air compressor.

Step 1: Thorough Checking

Air Compressor checking

Before draining or filling up the tank, you need to check the hydro-testing number on the CO2 cylinder. You can find this number on the tank’s body. You can skip this hydro-test if you’re using a smaller cylinder. Moreover, you can use the CO2 tanks if this was tested 5 years from use.

Step 2: Tank Ratings

Air compressor tank ratting

As all CO2 tanks are not the same, so they have different PSI ratings as well. The PSI rating is generally printed or found on the bottom side of the tank. AN example of this PSI number is “E3200.” Another way to identify the PSI number is, the number starts with a letter and has a lengthy serial number!

The letter or alphabet indicates the authority’s standard to which the cylinder complies. And the numbers after the letter indicate the main PSI rating of the CO2 tank. So in the above case, the PSI rating of the tank is 3200.

Step 3: Using Proper Filling Adapters

Proper filling adapter for air compressor

Well, this is the part where people seem to be less concerned. Although they do check the PSI ratings and the tanks, they somehow end up using the wrong adapters for fitting.

While you fill up your tank, things don’t always work as they should be. To connect the CO2 tank with air compressors, you need a few adapters. This is very important for knowing how to refill the CO2 tank with the air compressor properly.

If you look closely, you’ll see some marks like CGA-320 or CGA 347. You need to understand these terms for knowing about the fittings of your CO2 tank and air compressor. So get a firm grip on these terms before handling your CO2 tank. Also, use a complete sealer to avoid gas leakage.

Step 4: Empty the Tank

Draining air compressor tank

Before you fill-up the CO2 tank with new air, you need to drain out the remaining air in it. First, you need to connect the CO2  fitting with the compressor hose. Then tightly screw all the fittings in it.

Find the bled-off valve at the upper side of the fitting. Unscrew it to let the remaining air go out of the tank. This will free up the tank and also provide a better accuracy while you refill it. After you let all the air out, reconnect the bleed-off valve to its place properly.

Step 5: Fill the CO2 tank with Air Compressor

CO2 filling on air compressor

For refilling your CO2 tank, a high-pressure air compressor is a must. You need to use compressors that can go more than 150 PSI. So avoid using hand pumps or low-pressurized ones. The compressor rating will depend on the size of your CO2 tank.

To calculate the size, measure the length of the CO2 tanks and multiply it by 2. Suppose the length came 10 ounces. So you’ll need the air of 10*2=20  seconds. Calculate the time using a hand watch or stopwatch while filling it up.

The compressors have a built-in pressure gauge to measure the pressure and bleed-off valves. Connect the compressor with the CO2 tank and start the stopwatch immediately. This part is important as any error can lead to dangerous outcomes.

You need to fill your CO2 tank accurately. Filling it more will create an imbalance inside the tank. This might even end up damaging the cylinder as well.

If you somehow fail to fill it up accurately, always underfill for everyone’s safety!


Can I fill the CO2 tank with compressed air?

There are certain valves in CO2 tanks to allow liquid filling. The filler nipple only works for liquids. But we all know, that compressed air doesn’t remain in liquid form. As a result, you can’t use compressed liquid to fill CO2 tanks.

Can you compress CO2 with an air compressor?

We all know people use air compressors to compress gases. There are Reciprocating pistons as well as a screw compressor that can compress the gases. So yes, you can compress CO2 with an air compressor.

How do you fill a CO2 tank at home?

Filling up a CO2 tank at home involves some processes.

  • Property checking the tanks for any kinds of damage or leaks.
  • As CO2 tanks can be different based on their usage, their rating is also different. So before you try to empty or refill the tank, know the PSI ratings of your tank first!
  • To connect the compressor with the tank, you’ll need some tools or adapters. Check if you have all the necessary adapters or not. Also, avoid gas leaks by using a sealant.
  • Now empty the tank to let go of the raming air in the CO2 tank
  • Connect the air compressor with the CO2 tank with all the adapters and fill it up!


As you’ve read this far, we hope you now know how to refill CO2 tank with air compressor. Knowing the proper steps makes the refilling job easy and safe.

If you’re not confident enough, don;lt hesitate to ask for an expert’s help. But we believe you won’t be needing this as we simply explained everything. Good luck!

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Oliver is an efficient interior designer and part-time content writer of TopToolsLab. He has strong research skills about tools, accessories, and products such as drills, saws, air composers, cutting machines, etc. He knows the correct uses of the part of every tool. He can give proper information and meaningful description to find out the perfect result of the tool.

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