Air compressors are known for their reliability and for doing tough jobs easy. Therefore used for so many tasks. Many people asked me about how to refill Co2 tank with air compressor?

So today I will share a detailed guide about how to use air compressor for filling Co2 tank.

How To Refill Co2 Tank With Air Compressor

Table Of Contents

How To Refill Co2 Tank With Air Compressor

You need a high-pressure air compressor with large tank size to fill a Co2 tank with an air compressor. Your air compressor must match the requirement to fill the Co2 tank. Co2 tanks are rated for 1800 PSI or 3000 PSI in most cases.

Never fill the Co2 tank beyond its rated capacity. Overfilling a tank can lead to serious damage.

In this article, we will discuss it in detail. But first, let’s dive into some basic details.

What is a Co2 Tank?

You will find many definitions and articles on the internet describing Co2 complicatedly. But let’s keep it simple here.

A Co2 tank is a container where Carbon Dioxide (Co2) gas is stored. This container is made up of aluminium to make it resistant and lightweight.

A Co2 tank comes with a safety pressure valve on top and a screwed steel cap to hold the gas and protect the tank from the explosion.

This valve is used to turn ON the flow of gas from the cylinder or turn it off.

How to Refill Co2 Cartridges

Along with performing many other tasks, an a garage compressor can also fill an empty Co2 tank.

If you have had a Co2 tank for some time, you know how much effort is required to bring your Co2 tank to the refill station to get your tank refilled. Besides the real struggle, you also have to pay the money.

But if you own an air compressor, you can save both your time and money because you can refill the Co2 tank with an air compressor without spending a single penny.

Things Needed to Refill Co2 Tank With Air Compressor:

Co2 Tank
Co2 Tank Fitting
Air Compressor (high-pressure)
A Stop Watch

Easy Steps To Refill Co2 Tank With Air Compressor

Step 1 – Verify your Co2 tank quality

Step 2 – Know your Co2 tank PSI rating

Step 3 – Use the right fittings

Step 4 – Drain your Co2 tank

Step 5 – Use a high-pressure air compressor to fill your Co2 tank

Step 6 – Start filling your Co2 tank

Step 7 – Turn off your air compressor

Step 1 – Verify Your Co2 Tank Quality:

First, you have to make sure your Co2 tank is in perfect shape and condition to be refilled. Look for a hydrostatic testing number printed on the side of your Co2 tank.

What is Hydrostatic Testing?

Hydrostatic testing is a process that is required by US law. In Hydrostatic testing, the gas cylinder is checked for multiple factors such as strength, leaks, condition etc.

How is a hydrostatic test performed?

Hydrostatic testing involves multiple steps. First of all, the tank is drained completely. When all the gas is removed, and the tank gets empty, it is filled with water.

After that, the tank is pressurized up to 1.5 – 2 times more than the rated pressure to ensure the Co2 tank is in good condition and can handle the Co2 pressure.

If the tank is old or has some issues, the water starts leaking, which uncovers all the damages and issues. The aluminum Co2 gas cylinders require this hydrostatic testing every five years. A date stamp is engraved/printed on the cylinder after testing. (as shown in the image below)

If you have a small Co2 tank and have done the initial inspection, hydrostatic testing is not needed for such small tanks.

But if your Co2 tank is of normal size and can’t find any hydrostatic testing number on your tank, don’t proceed further and stop at this stage because it is crucial to observe each safety measure to prevent any unwanted incident.

Step 2 – Know Your Co2 Tank PSI Rating:

It is very crucial to know the PSI rating of your Co2 cylinder.

Co2 tanks are rated for 1800 PSI and 3000 PSI in most cases. PSI rating is printed on the side of the tank.

The PSI rating is written in this format: (LNNN) or (LLNNNN) etc

PSI rating always starts with a letter, followed by numbers.

The letter in this PSI rating indicates the specifications of the regulatory authority. The following numbers are the actual PSI ratings.

Step 3 – Use The Right Fittings:

Always make sure to have the right size fittings before you start filling your CO2 tank.

If you own an air compressor, you may already have various types of fittings for your air compressor. But it is very important to know the required fittings to refill the Co2 tank with an air compressor.

You will need the right fittings that will fit the purpose to fill your Co2 tank.

So always read the seal on your Co2 tank to know the thread size and diameter of your Co2 tank so that you can use your fittings accordingly.

Step 4 – Drain Your Co2 Tank:

Before you start refilling your Co2 tank, make sure it is empty. It is an important step because you never know how much gas is still present in the tank.

To drain your Co2 tank, you will need an air compressor hose along with proper compressed air fittings.

Attach your air compressor’s hose fitting to the Co2 fitting. Now tightly screw the other end of the hose fitting into the Co2 tank.

There is a valve at the top of this fitting to bleed out the gas. Unscrew this valve. It will let the excess gas out from the tank. (See the image of the bleed valve below)

If you have an adapter, it will make the draining work easy.

Simply hook up your adapter to your Co2 tank. Now tighten the adapter with a wrench.

Now unscrew the bleed valve. It will let the excess gas out from the tank.

Once all gas is bleed-out, screw back the valve at its earlier position before filling the tank.

Draining the tank gives you better accuracy and understanding when refilling the tank.

Step 5 – Use A High-pressure Air Compressor To Fill Your Co2 Tank:

Before starting the refilling process, make sure your air compressor matches the required PSI rating of the Co2 tank because a high-pressure air compressor is required to refill the Co2 tank. Smaller air pumps will not suffice for this task.

There are some air compressors available in the market dedicated to Co2 tank filling. These compressors match the PSI rating required to fill the Co2 tank.

Also, they have an easy-to-drain set up to empty the tank before refilling. Also, these compressors auto-stop when the tank gets full, avoiding the danger of extra pressure build-up, and in some cases, chances of explosion.

But in commonly used high-pressure air compressors, you have to handle all these factors manually.

Step 6 – Start Filling Your Co2 Tank:

Once you are fully satisfied with all the abovementioned factors, proceed to the main step.

It is very important to know how much air pressure is required to refill a Co2 tank and how much time?

A common rule of thumb to determine it is to multiply the size of your Co2 tank by 2. That is the amount of time you will need to refill your Co2 tank completely.

To summarize: It should be 2 seconds per ounce.

For example, if your Co2 tank is 10 ounces, you will need to run your air compressor for 20 seconds.

That’s why it is important to have a stopwatch with you or run it on your mobile.

There is very little margin of error when refilling a Co2 tank.

A slight mistake can result in overfilling, which can damage your Co2 tank your air compressor fittings, and in the worst case, one can get seriously injured if the tank gets blown.

Step 7 – Turn Off Your Air Compressor:

Turn off your air compressor when your stopwatch reaches the calculated time required to refill your Co2 tank.

Before removing the air compressor hose, unscrew the bleed valve for a second to release the built-up pressure.

Now remove your air compressor hose from the Co2 tank.

You are all done! You’ve successfully refilled your Co2 tank with an air compressor.

If you are a frequent Co2 tank user, these simple steps will make your life easy, and you can refill your Co2 tank yourself at home free of cost.

Can Co2 tank explode?

Yes! Co2 tank can explode if it becomes very hot.

Let’s discuss it in detail.

All compressed gasses such as Oxygen (O₂), Nitrous Oxide (N₂O), and Carbon Dioxide (Co2) have normal room temperature. In containers, these gasses can’t be stored in their original state.

But when these gasses get too colder, they can be stored in gas containers.

Therefore, it is crucial to maintain the cold temperature.

The pressure of these gasses inside the gas tank rapidly increases when stored in sunlight or a hotter place.

These gasses expand in volume inside the gas container when the temperature increases.

This pressure keeps increasing if not taken care of, and the Co2 tank finally explodes like a heavy bomb!

Every Co2 tank has a safety pressure valve on top and a screwed steel cap over it to hold the gas and protect the tank from the explosion.

But when the outer temperature increases at a level of 48°C to 54°C, the inner gas pressure increases rapidly.

The safety pressure valve and steel cap cannot handle such a higher temperature, resulting in a heavy explosion of the Co2 tank.

Periodic checking of safety pressure valve and steel cap is recommended. Also, always ensure that the surrounding temperature doesn’t go high to prevent unwanted incidents.

How Long Can You Keep Co2 In A Tank?

The duration to store Co2 in a tank varies upon usage. If the Co2 tank is rarely used, then the Co2 gas inside the tank will start to corrode the tank over time. Gradually, this tank will become unsafe to be refilled and reused.

Every Co2 tank has engraved a creation date, two digits represent the month, and the other two represent the year.

And as we discussed above, every Co2 tank goes through hydrostatic testing every five years as per US law. After the testing, the tank gets stamped.

Before this hydrostatic testing, it is ensured that the remaining gas inside the tank had not gone bad.

Safety Measures To Follow While Refilling The Co2 Tank:

Co2 is one of the most commonly used gases. But besides this, it is also a volatile substance.

So it is necessary to follow some basic precautionary measures before starting to refill the Co2 tank.

Don’t keep the Co2 tank on an uneven surface:

Don’t keep the Co2 tank on an uneven surface while refilling. If a Co2 tank drops down to the ground during the process, it can result in serious damage.

Keep the sick and children away:

When refilling the Co2 tank, always make sure no sick person is near you. Also, keep the children away from the refilling place for additional safety measures.

Wear safety goggles and safety earplugs:

It is advised to wear safety goggles and safety earplugs to prevent your eyesight and hearing if any unwanted incident happens because these are the most vulnerable parts and have the greatest chances of damage.

Make sure the tank is not punctured:

Before starting to refill your Co2 tank, always ensure that the tank is not punctured or have even the slightest leakage.

Keep the tank away from flammable materials:

Keep your Co2 tank away from heaters and any flammable material. Any such carelessness can result in a heavy fire or an explosion of the tank, which can cause serious injuries.

Keep an eye on the stopwatch:

Always keep an eye on the stopwatch during the refill process because there is very little margin of error when refilling a Co2 tank.