If you have an air compressor on hand, there are many really helpful tasks that it can handle for you. You will be able to use this handy item for pressure washing, tools for your car repair needs, and more.
This is one of the handiest items to have in your home shop or garage for a whole variety of reasons. Many people ask if their air compressor can also be used to refill a CO2 tank.
You can refill a CO2 tank with an air compressor with ease if you know the right steps. You will need the right compressed air fitting for this function that can connect to the CO2 tank correctly.
You will also need to know how much capacity the CO2 tank has so that you know how long to run the air compressor as you fill it.
If you are ready to learn more about this process, you will need to read on to learn more!
Can You Use an Air Compressor to Fill a CO2 Tank?
As stated before, you can use your air compressor for this need. You will need to follow the right process to be sure that you are going to be able to fill the tank correctly. Making an error in the amount of CO2 that you put in the tank can cause dangerous conditions since CO2 is not safe to work with unless handled correctly.
Making sure that you have the right fittings on hand and you know exactly how much CO2 to put into the tank is crucial to maintain safety as you complete this process.
You will need to be sure to calculate the amount of CO2 that is needed and then make sure that you are aware of the pressure that is being used to impart it to the tank. Overfilling a tank can lead to damage and might even lead to conditions that could injure you.
How Do You Fill a CO2 Tank at Home?
1. Verify Tank Integrity
Tanks will have the most recent date of hydro-testing printed on their side in plain sight. They are usually required to be tested every 5 years. Small units may not need to be tested after the initial testing. If your tank was tested in the last five years, it is safe to use. If not, you will want to have your tank tested again before you fill it or use it.
2. Know Your Tank Psi Rating
This is a crucial part of the process of filling your tank safely. You will see that your tank has a psi rating on the side.
Tanks will be rated for 1800 or 3000 psi in most cases. You must NEVER fill a CO2 tank beyond the capacity that it is rated for. If you are filling with 100% dry and oil-free, you can fill right up to the rated capacity.

If you are not sure that you are filling with dry and oil-free, you should fill the tank to slightly less than capacity. A common rule of thumb is to calibrate for 2 seconds per ounce. This means that you would need 24 seconds to fill a 12-ounce container.
3. Pick the Right Adapter
This is as important for safety as knowing the capacity of your tank and the psi it is rated for.
You will often have access to various fittings if you have an air compressor at home, and you might think that various of these fittings will work for this need. CO2 tanks often have a GGA-320 threading.

You will need to use a fitting that is made for this kind of threading. If you do not have a complete seal, the process will not work and you might also not be sure how much CO2 you are putting into the tank. Make sure that you have the right size fitting before you start filling any CO2 tank that you own.
4. Make Sure the Tank is Empty
Before you fill it, you need to purge the tank. Simply hook up your adaptor to the CO2 tank and allow the air to purge out.
There should be a valve that can be opened to purge the tank and remove the remaining air as well. Make sure that you have closed this valve before you attempt to fill it.
5. Use the Right Air Compressor and a CO2 Tank
You will need a CO2 tank to refill your smaller CO2 containers. You can often buy these at welding stores to fill your smaller canisters. You will also need a high-pressure air compressor.
A hand pump compressor will not work for this need. Make sure that your air compressor pressure matches the rating on your CO2 container.
There are some air compressors that are made specifically for the process of filling CO2 containers and they will offer you the right built-in psi settings as well as a handy bleed-off valve for your needs. These compressors often auto-stop when the CO2 tank is getting too full.

That being said, you can use a regular air compressor that you are using for shop functions so long as it is capable of creating the pressures needed to fill your canisters.
What Kind of Safety Considerations Should I Worry About?
As mentioned before, CO2 is a volatile substance, so you will need to be sure to follow the proper safety procedures when you are filling up CO2 canisters in your garage or your shop.
You will want to be meticulous about maintaining safety so that you do not have an issue that leads to injury.
- Do not drop a CO2 tank
- Never puncture a CO2 tank
- Keep the tanks away from all kinds of flammable materials. This could cause an explosion, so this is a very important consideration.
- Make sure that you are focused on your filling process. Overfilling can lead to a volatile situation as well as damaged canisters.
- Make sure that there are no other people nearby when you are filling CO2 tanks for added safety.
Many people also wear safety glasses just to be sure that their eyes will be protected in case something goes wrong.
You can never be too safe in shop settings or when working with compressed air for any purpose. If you feel like you cannot maintain safety, you should not fill CO2 tanks in your garage or your shop, particularly if there are other people around.
What is Hydro-Testing?
As mentioned earlier, this is the process that is used to test your CO2 tank for damage. This has to be done every five years for most tanks.
Some smaller tanks will not need a second test after the initial one. This test is required for all of these kinds of tanks to be sure that they are safe for use.
This process is done by removing all the air and inserting water into the tank. The tank is pressurized to up to 1.5 times the rated pressure to make sure that the tank has the integrity to hold. This testing uncovers leaks, ruptures, or damage that the tank has suffered.
This is testing that is actually required by law in the US, and you must take care to do this testing if your tank has not been tested within the last five years.
There are a variety of ways that this testing is performed, but all of them test for the same kinds of flaws and problems within the tanks to make sure they are safe for use.
Can You Safely Put Compressed Air into a CO2 Tank?
You can use your CO2 tank to hold compressed air, but this requires that you make sure that you are filling the tank properly. If you make an error, the CO2 tank could explode.
This is one of the processes that is not recommended for CO2 tanks that some people do anyway. You will be working with a higher pressure inside the tank, and you will need to calculate for this variable to avoid injury or damage to the tank that you are filling.
Refilling a CO2 Tank With An Air Compressor Requires Attention to Detail
If you are going to be refilling your CO2 canisters or tanks at home with your air compressor, you will need to be sure that you follow these steps with care.
There are numerous variables that could lead to injury or damage to the tanks that you should avoid at all costs.
If you are thinking of completing this process with your own CO2 tanks, make sure that you learn all about the process and that you have the right fittings for your air compressor before you start this process.
Being sure that you can maintain safety while you are filling CO2 tanks is crucial if you are going to be using this process with your home compressor. Make sure that you have the right fittings as well as a quality air compressor before you attempt to fill CO2 tanks yourself.