How to connect two air compressor tanksHow to connect two air compressor tanks

If you’re tired of waiting for an air compressor to refill after use, one way to solve this problem is to connect two tanks.

Connecting two air compressor improve the performance and ease the use of your air compressor. This way, you can keep up with your tools, so you don’t have to wait for the tank to finish filling or emptying before you begin using it.

Many air compressor users ask this question: What is the best way to connect two air tanks? 

Connecting two air compressor tanks is very easy and can be done by anyone with few tools. This will not cost you much except for the extra fittings that you will need to buy. In this article, I will show you how to connect two air compressor tanks and the benefits of adding two tanks.

How to connect two air compressor tanks – ultimate guide

Here is the step-by-step guide about connecting two air compressor tanks.

Step 1: Tools and Materials Needed:

  • The new air receiver tank must have a high capacity compared to the old one.
  • RTV silicone adhesive
  • Brass Tee Female NPT – 1/4′
  • A brass coupler fitting – 3/8′’ to 1/4′′
  • Female NPT brass coupler – 1/2 – 3/8′′ 
  • Compressor hose

Step 2: Unplug the compressor and drain it.

Before we go too in-depth about connecting two air compressors, turn off the power supply to the existing air compressor tank. Then close the shut-off valve on the downstream side of the regulator.

Finally, open the discharge valve of the existing tank and drain out as much air from it as you can.

Why is it important to drain the compressor?

Draining the compressor tank before connecting it to another tank will lower its internal pressure and reduce its wear and tear.

Step 3: Remove the Safety Valve

After draining out the compressor tank, now remove the safety valve. Take your time to unscrew it carefully with your adjustable wrench. Do not put any pressure on the safety valve as they are very delicate and can be damaged with too much force.

Now at this point, make sure you have ready Brass tee. You may make a Brass tee by securing the threads on the male side with RTV silicone adhesive.

Next, attach the Tee to the same location where the safety valve was attached. Again, you must make sure your Tee is the right size so that it can fit perfectly without any gaps.

If you want your safety valve to function properly, I recommend that you must remove any residue on the threaded end and coat it with RTV silicone.

Now it’s time to install your brass tee by fixing the safety valve into its female end.

Why is it important to remove the safety valve?

The safety valve is very important because it prevents your tank’s pressure from going beyond its limit. If you fail to install the Tee at the right spot, it may lose air pressure.

Having a proper fitting tee enhances the performance of your compressor. The safety valve will have to work less when the air pressure from the new tanks is added to the existing tank. So installing a tee is important for the smooth running of your compressor.

Step 4: Connect Hose

The next step is to connect the air compressor’s hose from one end of your brass tee, and the other end should be attached to your new Air tank.

Make sure the pressure of the hose must be in between one and half times to double what your existing tank can hold.

Note: Always check your air compressor hose, if you see any leak on your hose, fix it as such as possible.

Step 5: Set up the new air tank

This step is all about fine-tuning the new air compressor. To begin, disconnect the tools from the tank top and connect the coupler to where it was before.

Second, prepare the male thread of the 1/2″, 3/8″, and coupler with RTV adhesive. Now connect the coupler to the tank top with an impact driver and wrench.

The third is to secure the 3/8’′ to 1/4’′ screw and reducer into the previous coupler using adhesive, and finally, attach the new air compressor hose.

Step 6: Fill the tank

Now you have a new tank, and everything is working normally, so it’s a good time for you to fill up your new air compressor tank and the existing one.

To do this, you have to open all valves for both tanks, then turn on your compressor’s power, and turn on the power supply to the new tank’s regulator. When you hear a click sound, it is an indication that your compressor has started working.

The next important thing is that you should not fill your tank beyond its capacity. If you do that, it may ruin your compressor’s motor, valves, and other internal components.

So better fill the air tank at its capacity. Use a gauge to check the tank pressure, and it should be around 120 pounds per square inch. If you have a compressor with a pump regulator, I suggest you use it to fill up the tank as it will control the air pressure.

What is the reason behind filling the tank?

Filling your new air tank with the right amount of pressure is crucial as it will let you work for a longer period. Before filling the compressor tank, make sure your coupler and reducer are firmly fixed. If the pressure in your new tank is less than the existing one, then it will not function properly.

Step 7: Use your compressor

Now that you have installed a new tank, the next thing is to use your compressor. Run it for around one hour with a normal load, and then check if everything is working fine. If the pressure inside the tank drops, then you need to find out the reason.

The most common reasons for a tank pressure drop are that you have not attached the fitting properly or overfilled the tank. Make sure to check your connections and then restart the compressor.

If you find anything wrong, stop the compressor and fix the problem. Don’t start it again until you have found and fixed the issue. If everything is working fine, then you can feel good that you have installed a new air tank.

Things to consider when adding two air compressor tanks

  • Make sure your compressor’s horsepower is up to the mark for two tanks.
  • The size of the tank should be according to its workload capacity.
  • Use tanks of similar working pressures and PSI ratings.
  • Always check the pressure of your existing tank before filling up the new one. If it is higher, I suggest you use a regulator to ensure the pressure does not exceed its limit
  • Never overfill your new air compressor tank. It may damage the compressor and the tank.

Benefits of connecting two air compressors

There are several advantages to linking the two air compressor tanks. We’ll go through some of the major advantages:

CFM boost

The most important benefit of having two tanks is that your CFM will increase. If your compressor has a larger tank, it will allow you to work for longer hours without compromising the pressure.

As a result, your problems of short air supply will be solved. You can easily use your compressor for multiple purposes like filling tires, carbonating beverages, and other household chores.

But one thing here I want to explain (If you’re thinking adding another tank will increase the system cfm, you’re mistaken).

Adding another tank just increases the amount of available cfm so that you can power more air tools/equipment simultaneously.


You will be surprised to know that the cost of connecting two air tanks is less than buying a new one. Also, you can upgrade your system at a later time when you need more capacity.

For example, if you have an air compressor with a 40-gallon tank and your work requires more CFM, you can connect a 60-gallon tank. This will allow your worker to use the compressor for a longer time before it needs to refill.

This way, you will not need to purchase a new compressor at the cost of hundreds of dollars.

Squeezing out every bit of performance

If your existing compressor is working at its full potential, but you need more power to meet the demand of your work, then using a second tank will allow you both to get the best performance out of your compressor.

Final Words

This article has covered the different options to connect two air compressors. We have also discussed the benefits of adding a second tank, how it will increase your working time and performance, and things to look out for when adding a second tank.

I hope this article has helped you understand the benefits of connecting two air compressor tanks and how it can be done easily. If you have any questions, please leave a comment below, and we will get back to you soon.

FAQs – Frequently Asked Questions

Will connecting my air compressor tanks cause any problems?

Two tanks will give you more volume of your air tools which means less time to wait for the tanks. Having two air compressor tanks will help you use them in different works that require more compressed air.

Can I install a regulator on my new tank?

You can add a regulator and control valves to your new air compressor tank. This will allow you to control the tank’s pressure and reduce wastage.

What is the function of an air compressor check valve?

An air compressor check valve (air receiver check valve) is used to prevent the backflow of compressed air. It prevents the air from going back into the tank when it is not used.

How does a check valve fail?

A check valve can fail in two ways. First, it may cause damage to the compressor tank due to high-pressure. Secondly, if there is a small amount of water or dirt in the check valve, it can lead to damage. So make sure you check this properly before starting using your air compressor.

What is the function of an air compressor unloader?

An air compressor unloader is also called an air receiver unloader. They are used to release pressure inside a compressed air tank. Unloaders allow the motor to start up easily as it does not have to overcome the full tank pressure.

By Matthew

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