How to Fill Scuba Tanks: A Complete Guide

How to Fill Scuba Tanks: A Complete Guide

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Scuba diving is a wonderful experience to remember. Yet, it could be very dangerous if your equipment’s not properly checked. And what’s more important to check and maintain than your scuba tanks? That’s how you’d be breathing, after all.

Filling your scuba tanks, although easy, is a very serious task with many potential hazards. That’s why if you’re attempting to do it by yourself, you have to carefully read and cautiously apply all the steps in this guide. That way, you can be sure of your safety over and under the water.

Want to know more about how to fill scuba tanks in detail? Stay with us.

How to Fill Scuba Tanks: Step by Step

So without further ado, let’s dig deeper into this process with all its fine details:

1.   Check the Tank

Inspecting the tank before attempting to fill it is the most crucial step. That’s because a damaged tank means air leakage within it. Additionally, if you go into the water with a cracked tank, the crack might get wider under high pressure leading to fatalities.

Here’s how to check your tank:

Check for Any Visible Damages

Check any markings, dents, or changes on the tank’s surface. In addition, have a look over all the valves and the gauges for any unexpected complications.

If you observe any considerable damage, you shouldn’t use the tank anymore.

Shake the Tank Gently and Listen Carefully for Any Unexpected Sounds

For the tank to remain in its optimum condition, it has to stay dry. If there’s anything inside, you shouldn’t use that tank.

To check this dry condition of the tank, gently shake it and be all ears for any sounds that might come up. If there’s a sound of a moving liquid, then you have to get rid of the tank.

Put the Tank in a Cold Water Bath

Putting the tank in a cold water bath will furtherly determine if there’s any leakage. At this step, you have to Look closely at the water for any bubbles. Moreover, the sight of bubbles means that there are holes in the tank.

Also, the cold water bath cools the tank efficiently for the filling stage. As in the filling stage, the tank will have hot air coming inside of it due to the high pressure. Therefore, if you don’t cool the tank before filling it, accidents might occur.

2.   Remove Any Extra Air in the Tank

You have to release any extra air in the tank before refilling because filling over existing air will make the tank strained. Strained tanks might wear out more quickly, in addition to being sensitive to any external blows.

Therefore, any tank filled with over 10 pounds of pressure should be rid of its excess air before refilling. To release the air, open the valve slowly and let it drain at a slow pace.

For this step, You might need to attach a gauge to the tank to be able to monitor the pressure level inside.

3.   Set Up the Air Compressor

To fill the tank, you’ll need an air compressor, but not the usual compressors that you can find at any hardware store. Instead, you need a special one made specifically for scuba tanks.

Scuba compressors are different as they provide high levels of pressure in the range of 3,000 psi (3,000 pounds). Moreover, they contain filters that dispose of any harmful components inside the tank and replace them with clean, breathable air.

Before filling, you have to set the compressor at the required pressure and size settings. Furthermore, if the compressor doesn’t contain an automatic shut-off feature, then you have to stay near to shut it down when the pressure is enough.

4.   Attach the Compressor to the Tank

Attach the compressor’s yoke (hose) to the tank’s valve. Make sure that the ending points of the yoke are clean of any dirt and debris that might get displaced inside the tank. Secure the connection so that no air can escape, but rather, all the air enters the tank smoothly.

Bear in mind that yokes have different sizes, depending on the size and the type of tank it’s installed in. Accordingly, you should use the yoke that’s specific to your tank.

5.   Fill Up the Tank

Once the yoke’s tightly sealed at both ends, you can turn on the compressor and fill up the tank.

While filling, check the gauges to observe the pressure level elevating inside the tank. On reaching the desired level, shut down the compressor to avoid overfilling the tank.

If the compressor contains an automatic shut-off, you wouldn’t need to shut it down by yourself. However, staying near is necessary in case the feature malfunctions. If it does, shut the compressor down or remove the plug.

6.   Store the Tank Properly

After filling the tank, let it settle for a few minutes, as the tank is now filled with hot air. After that, you’ll need to store it somewhere safe til you reach the time for your next scuba diving trip.

The following are a few precautions that you need to take so the tanks wouldn’t get flawed during the storing process.

Store the Tank in a Relatively Cold Area

Storing at hot locations could be very dangerous. That’s because the increased temperature of the surrounding will increase the internal temperature of the air inside the tank.

In turn, the increased internal temperature will accelerate the gas expansion inside the tank, which might cause an explosion.

For this reason, storing in cold areas will keep you and the storing location safer.

Store the Tank in an Upright Position

Storing the tank at its side may change the composition of the gas inside it. Additionally, if there’s any water leakage at the storage location, it might affect a larger area of the tank.

Thus, causing more rust and corrosion on the tank’s surface, which will significantly decrease its durability.

Therefore, store it in an upright position to prevent this.

Secure Tanks Together at the Storing Location

Since you’re going to store tanks at an upright posture, there’s a chance that they might fall over.

To avoid this, make little or no room for the movement of the tanks. Furthermore, secure the tanks together with towels in between so they won’t bump into each other.

In addition, you might want to put something up against them so they won’t tip over.

Final Thoughts

How to fill a scuba tank isn’t that hard. Yet, it has to be done with elaborate attention to ensure that the tank wouldn’t fail under the water or cause an explosion on the ground.

To fill a scuba tank, you need first to check the tank completely for any holes and dispose of the tank if there’s any gas leakage.

Then, you’ll need a scuba air compressor to fill the tank. Next, you have to make sure that the yoke is secured tightly at both ends of the compressor and the tank. After that, you can begin filling the tank.

Lastly, you have to stay nearby to shut down the compressor if anything goes wrong or if it doesn’t have an automatic shut-off.

Jack Thompson

Jack Thompson, a scuba diving enthusiast from San Diego, has spent over a decade exploring the underwater world across the globe. Sharing his passion through captivating stories and informative articles, Jack aims to inspire others to embark on their own scuba diving adventures and uncover the ocean's hidden treasures. Follow Jack on Twitter, Pinterest, Reddit, and Facebook or email him at

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