Do Air Compressor Tanks Expire?

Air compressor tanks are designed to hold pressurized air. They’re made to withstand more pressure than the max PSI rating of the compressor, for safety’s sake. But, like anything else, compressor tanks can wear down over time. And they usually do this from the inside out, since condensation builds up inside the tank and can cause rust. So it’s common for people to wonder if air compressor tanks expire. 

Most compressors designed for home use don’t have a set expiration date. However, carry tanks and some other compressor tanks, usually used in industrial applications, do have discard dates past which they shouldn’t be used. You can check your compressor and see if it has an expiration date.

If your compressor doesn’t have an expiration date located on it, that doesn’t mean that you should use it forever. It simply means that you should use common sense, perform regular maintenance, and look out for signs that the compressor is failing. All of which we’ll cover in this article. 

Why Do Some Air Compressor Tanks Have an Expiration Date?

It’s worth noting here that we’re talking about the tank on an air compressor. These are very different things than portable air tanks, sometimes called air carrying tanks, that you can fill up with a compressor and then take it with you to fill tires and such. Air carrying tanks do have “discard by” or “destroy by” dates, usually on one of the legs

These air tanks don’t generally have drains and they are low-cost and often cheaply made, so using one past its expiration date is not the best idea. However, there are many people who think this date is just a suggestion, and they continue to use their portable air tanks long past the date. 

Many industrial compressors have expiration dates, too. These are required by law in many places, and compressor service companies won’t work on a compressor that has passed its expiration date. However, sometimes these tanks just need to be tested and recertified for continued use. 

How Long Do Air Compressor Tanks Last?

There’s not even any broad guidelines for how long a compressor tank is supposed to last. It depends on many factors, and the lifespan of a compressor tank can be as little as a few years or as much as a few decades. 

These factors include:

  • How much use the compressor gets
  • How often maintenance is performed (mainly draining the moisture)
  • What the compressor is used for
  • Where the compressor is stored
  • The quality of the compressor
  • The humidity in the air

Your average compressor for home use can last for 10 to 15 years easily, with the proper storage and care. 

How to Tell if Your Tank Has Expired

There are a few tips you can use to tell if your air compressor tank is past its prime. These aren’t all foolproof, but they’re a great start. 

  • Inspect the liquid when you drain the tank.
    • Look for little flecks of rust in the liquid when you drain the tank. The more rust you see, the worse off the inside of the tank is. 
  • Check the outside of the tank.
    • Look for dents, rust, pinhole leaks, and other signs of damage on the outside of the tank. 
  • Listen to the sounds.
    • Hit the top of the tank gently with a hammer or other metal implement. Note the sound it makes. Then hit the underside of the tank. If there’s a noticeable difference, you probably have a buildup of gunk and rust at the bottom of the tank, where moisture accumulates.
  • Test the tank
    • You can get the tank tested for pressure at a dive shop or welding shop. However, these tests can be expensive and may not be worth it, depending on how much your compressor is worth.  

When to Replace an Air Compressor Tank

If you find that there are a lot of rust particles coming out of your tank every time you drain it, you can bet that it’s nearing the time for a new tank. You can take it a step further and wait until you get a pinhole leak in the tank. If this happens, it’s definitely time to replace the tank. 

A pinhole air leak on the outside means that there’s a much bigger problem on the inside. Fixing that leak may help you use your compressor for longer, but it can also pose a threat since the inside of the tank is likely compromised. 

What Can Happen if You Use an “Expired” Tank?

The worst-case scenario of using an expired tank is that it ruptures under pressure. This can cause serious injury or death if anyone happens to be near the tank when it ruptures. And while this isn’t the most common thing that happens, an air compressor explosion can happen, and it’s important to keep this risk in mind. 

More likely, however, is that you’ll get a pinhole leak in the tank and you’ll start to notice that the compressor isn’t running well. Once that first leak happens, it’s only a matter of time before another one takes hold. 

If you’re using an air carrying tank past its expiration date, you could run the risk of having it rupture as well. These tanks don’t have drains, so water can build up in them if they’re used often. I’d advise you not to use one of these portable air tanks past its expiration date, especially since they’re so cheap to replace. 

Can Air Compressor Tanks be Welded?

Welding on any pressure-bearing tank is risky business, especially if you’re not trained to weld on such vessels. When it comes down to it, you’re taking a substantial risk by welding an air compressor tank, as it can make an explosion more likely. 

Most people wonder about welding an air compressor tank because they want to fix pinhole leaks near the bottom of the compressor. This is a very bad idea. The pinhole leaks are indicative of a larger problem inside the tank, so welding them closed is only putting a bandage on the issue. 

Many people suggest that you should never ever weld a pressure tank unless you are supremely confident in your welding abilities. A bad weld can cause the tank to rupture, which could kill someone. It’s best to just replace the tank or the whole compressor rather than take the chance that welding entails

Tips for Getting the Most Out of Your Tank

If you want your compressor tank to last longer, all you really have to do is regular maintenance. Thankfully, this is pretty easy stuff. Follow these tips to ensure your compressor has a long life. 

  • Drain the tank after each use – The longer you allow water to sit in the tank, the faster it will corrode. Drain the liquid after each use to prevent corrosion. 
  • Replace the air filters – Replacing the air filters on-time is another great way to ensure a long life for your tank. 
  • Change the oil – If your compressor requires oil, make sure to change it according to your owner’s manual. This will help protect the motor. 
  • Use a water separator – If you’re really concerned about moisture in the tank, purchase a water separator to help keep the interior dry. This can add years to a compressor, especially if you live in a humid area. 

In Conclusion

If you head out to your garage right now and look at your air compressor, you probably won’t find an expiration date on it. Most home-use compressors don’t have “use by” dates — at least in this country. But if you have a portable air tank that you fill up with your compressor, that tank probably does have a “destroy by” date on it. And it’s good to pay attention to. 

To extend the life of your air compressor tank, get acquainted with your owner’s manual and remember to drain the tank after each use. Moisture is the big killer of air tanks, so if you take steps to limit moisture, your compressor tank will enjoy a nice long life.

Justin

Justin is a full-time blogger with a passion for anything DIY. When he's not hanging out with his wife and son, you can find him putting the finishing touches on yet another home project he's taken on. He's also the creator of AllAboutAirCompressors.com.