Why Drain Water From Compressed Air Tanks?

Draining the water from your compressed air tank is one of the most important parts of the routine maintenance that your compressed air system needs. If you do not routinely drain the water from your air compressor, you risk experiencing several different issues.
You should drain the water from your compressed air tank to help avoid condensation, rust build-up, freezing damage, and a contaminated air supply. Keeping the water drained can also help increase the overall volume of useable space in your tank.
This guide will cover these different factors in detail so that you can better understand the benefits of regularly draining the water from your compressed air tanks. It is important that you address any water accumulation in your compressed air tank as soon as possible.
This will help you avoid any serious issues that could arise from the pooling of water in your system. This guide will provide valuable information that can help you better understand the different reasons it is important to regularly drain your tank.

How Does Water Get In Compressed Air Tank?
Water gets in your compressed air tank due to the condensation caused by air compression. This is an unavoidable byproduct of any type of air compression due to the heating of the air when it is compressed into smaller volumes.
When this air cools, it creates condensation in your tank. This condensation can easily spread to other parts of your compressed air system and could potentially cause damage if left unchecked. Because of this, it is vital for the health of your compression system that you work out a schedule for regularly draining the water from your tank.
The humidity of the area that you live in will also affect the overall condensation level of the air being used in your compressed air system. If you live in an area with high humidity, you can expect to drain your tank much more often.
Why Should You Drain The Water From Compressed Air Tank?
You should drain the water from your compressed air tank to avoid condensation build-up, prevent rust and corrosion, and avoid freezing damage and a contaminated air supply. All of these benefits will be discussed in detail in the list below.
Prevents Condensation Build Up
Draining the water from your compressed air tank will lower the amount of condensation build-up present in your tank. Condensation is the major cause of many issues that your compressed air system could experience.
Emptying the water from your compressed air tank will remove the excess condensation and keep it to a minimum which will lower the chances of your compressor incurring damage. While it is not possible to completely prevent condensation from forming in your compressed air tank, draining it regularly will keep minimizing the chances of issues arising.
Prevents Rust And Corrosion
Draining the water from your compressed air tank will also help prevent rust and corrosion from forming in your tank. Rust and corrosion will cause damage to your pipes, tanks, and other metallic components which could lower the efficiency and lifespan of your machine.

When your tank begins to exhibit signs of rust and corrosion, you will need to address the issue as soon as possible or you risk permanent structural damage that could wind up making your tank unusable. Rust and corrosion in your compressed air tank also can also add additional contaminants to your air system and cause blockages.
Prevents Freezing Damage
Water that has collected in your compressed air tank will freeze in cold weather, causing your tank to become temporarily unusable and often resulting in permanent tank damage. The freezing water in the tank can cause the shell of your tank to become unstable and lead to breaks and leaks.
Water that has pooled in your tubes and hoses can also freeze, causing damage and airflow issues. While storing your compressed air system properly during the colder months can mitigate the risk of freezing damage, it is better to drain the system regularly to avoid it entirely.
Prevents Contaminated Air Supply
Keeping the water drained out of your compressed air tank will also eliminate the risk of pumping air high in condensation into your tools and other hardware that utilizes your compressed air system. Using a tank that has not been drained properly to send air to your tools and hardware could cause internal rust and corrosion.
This means risking the possibility of permanently damaging the internals of the tools and hardware that you use with your compressed air system. This makes it extremely important to check the water level in your tank before using it to power tools.
If you are using your compressed air system to affect the air quality while storing goods, the extra moisture being released into the air could damage stored dry goods or metallic products. Draining the water from your tank will keep the moisture being pumped out of your compressor to a minimum.
Increases Volume In Air Tank
Draining the water from your compressed air tank will also increase your tank’s overall volume of useable space. When water begins to pool in your air tank, you will lose valuable space that could be otherwise filled with air.
In some extreme circumstances, you could wind up losing up to 50 percent of your useable space due to excess water. If you are not getting the right amount of air out of your tank, you should consider draining the water and checking if that resolves your issue.

Losing usable space in your tank will cause your compressed air system to run less efficiently and can result in more frequent maintenance and tank replacements. You can avoid these issues by simply draining the water from your tank regularly.
How Often Should I Drain My Compressed Air Tank?
You should drain your compressed air tank at least every month to ensure that significant water pooling does not occur. Keep in mind that your compressor usage, storage environment, and humidity exposure will ultimately determine how often you should drain your tank.
Generally, draining once a month will help you avoid any serious issues that could be caused by condensation build-up. You should consider installing an automatic drain valve on your tank. This will automatically drain your tank when it detects certain water levels present.
You can purchase an automatic drain valve for around $115. You can save money by purchasing your automatic drain valve online. The table below contains popular vendors and their prices for automatic drain valves.
Vendor | Avg. Automatic Drain Valve Cost |
Walmart | $117 |
Amazon | $112 |
Lowes | $125 |
Home Depot | $109 |
Harbor Freight | $111 |
Final Thoughts
This guide has provided you with all of the information that you need to better understand the benefits of draining your compressed air tank regularly. As this guide indicates, leaving water pooled in your compressed air tank can cause several serious issues for your compressed air system.
Excess condensation in the air can cause water to pool in your tank. When the moisture is dispersed through your compressed air system, the likelihood that you incur rust damage, air contamination, and freezing damage increases exponentially.
It is vital that you address any significant water build-up as soon as possible, or else you run the risk of incurring serious damage to your compressed air tank and system components. The information in this guide can help you get into a routine that can prolong the lifespan of your compressed air system.