Air compressors are used used for so many tasks and is known for their reliability and for doing tough jobs easy. But today we will discuss about how to fill HPA tank with air compressor.

How To Fill HPA Tank With Air Compressor

You need a high-pressure air compressor with average sized tank to fill an HPA tank with air compressor.

Your air compressor must match the requirement to fill the HPA tank.
A normal home air compressor goes up to 100 – 150 PSI, which will not be enough to fill an HPA tank.

For the lowest pressure operating marker, you will need at least 180 – 250 PSI.

For high pressure operating marker, you will need at least 250 – 350 PSI.

Some compressors operates best at 800 – 1100 PSI.

Never fill the HPA 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 an HPA Tank?

Compressed air is also known as High-Pressure Air (HPA). Compressed air is just what it sounds like, compressed atmosphere. 

An HPA tank stores oxygen or breathable air after getting compressed.

An HPA tanks have a regulator and gauge. The regulator allows you to control the air pressure, which you want to be delivered to your paint gun. And the gauge shows the amount of compressed air left in the tank.

The control on air pressure gives you better control and accuracy, resulting in better performance.

HPA tanks are preferred over Co2 tanks because they are not affected by temperature.

How to Refill HPA tank with air compressor

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

If you have had an HPA tank for some time, you know how much effort is required to bring your HPA 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 HPA tank with an air compressor without spending a single penny.

Things Needed to Refill HPA Tank With Air Compressor:

HPA Tank

HPA Tank Fitting

Air Compressor (high-pressure)

Nozzle

Air Compressor Hose

Safety Goggles and Safety Earplugs

Easy steps to refill HPA tank with air compressor

Step 1 – Verify your HPA tank quality

Step 2 – Know your HPA tank PSI rating

Step 3 – Use the right fittings

Step 4 – Drain your HPA tank

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

Step 6 – Start filling your HPA tank

Step 7 – Keep Measuring PSI

Step 8 – Turn off your air compressor

Step 1 – Verify your HPA tank quality:

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

If the tank is old or has some issues, the water starts leaking, which uncovers all the damages and issues. The aluminum HPA 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 HPA tank and have done the initial inspection, hydrostatic testing is not needed for such small tanks.

But if your HPA 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 HPA tank PSI rating:

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

The standard HPA tanks output pressure is 850 PSI, but some HPA tanks can be adjusted from 300 PSI – 1100 PSI. PSI rating is printed on the side of the tank. PSI pressure can be adjusted by the regulator.

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 HPA 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 HPA tank with an air compressor.

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

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

Step 4 – Drain your HPA tank:

Before you start refilling your HPA 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 HPA tank, you will need an air compressor hose along with proper compressed air fittings.

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

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

There are some air compressors available in the market dedicated to HPA tank filling. These compressors match the PSI rating required to fill the HPA 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 HPA 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 an HPA tank and how much time?

A normal HPA tank takes around 10 – 30 minutes on average. If the tanks is completely empty, it will take more time. You may also find a fully empty tank too hot after complete refill.

Never fill the HPA tank beyond its rated capacity. There is very little margin of error when refilling an HPA tank.

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

Step 7 – Keep measuring PSI:

During the entire process, keep measuring the PSI of the HPA tank to ensure there is enough air in the tank. The pressure switch of the air compressor tells the reading of the PSI.

Step 8 – Turn off your air compressor:

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

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

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

Can HPA tank explode?

HPA tank can explode if you put oil in the tank through fill nipple.

So never ever put even a single drop of oil in an HPA tank, because it can create such large explosion which can easily blow up the top of a car. Must read this article to prevent HPA tank from exploding.

How long can you keep HPA in a tank?

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

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

And as we discussed above, every HPA 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 compressed air inside the tank had not gone bad.

Safety measures to follow while refilling the HPA tank:

It is necessary to follow some basic precautionary measures before starting to refill the HPA tank.

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

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

Keep the sick and children away:

When refilling the HPA 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 HPA tank, always ensure that the tank is not punctured or have even the slightest leakage.

Keep the tank away from flammable materials:

Keep your HPA 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 gauge:

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

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

Most Important Advice:

If for any reason, maybe due to lack of safety measures, or surrounded by many how to fill HPA tank with air compressor, then DON’T fill the HPA tank yourself.

Just go to the refill station and get it refilled by a professional person.

Always remember safety should be your highest priority.