How To Tell If Your Propane Tank Has Expired

An image of an expired propane tank.

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Everything great comes to an end, and this adage best applies to propane gas storage. For all its perfect qualities and almost utmost longevity, you still have something to be worried about at some point. 

And that’s about the dates on your, say, 500-lb propane tanks

Notably, you can store propane gas eternally, making it one of the ideal fuel sources for emergency scenarios. But one big factor stands in your way- propane tank lifespan. While it’s long enough to last a decade, you may have to think of it at some point. 

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Propane is a liquified gas that will become vapor if exposed to nature. This is why propane tank expiration is such a big issue. Today, we bring you all the insights on identifying expired propane tanks and the best measures to beat the expiry date.

So we invite you to be our ally as we unearth everything about this topic to help you improve on propane gas use.

How long are propane tanks good for?

Say that you’ve just purchased a new propane tank and wonder how long it’d take to finish its reserves

If your tank weighs 100 lbs or less, it will take approximately 12 years to expire. So that means it’ll be in good condition from its manufacturing date for this duration. If your tank is due or has passed the 12-year mark, it is time to return it to the supplier for requalification. 

The supplier will perform a thorough inspection to ascertain if you can continue using it or if you need an outright replacement. If it’s in good shape, has no leaks, and has no corroded parts, the supplier qualifies it for another five years. 

Who should Requalify your Propane Gas Tank?

Rather, who provides propane tank certification? In most US states, federal container laws dictate who’s responsible for the management of propane tanks. Among their fundamental rules is that the propane gas tank owner or agents are responsible for inspecting and filling the tanks. 

So this brings us to another interesting point. Do you own a propane gas tank the moment you buy it? 

Contrary to what many may believe, propane gas tanks are owned by the supplier who gives you the tank. That’s why it’s crucial to pick the right supplier. Therefore, you’re a lessee, and thus you’re unauthorized to fill the tank. Your role is to keep track of the propane tank certification and inform the supplier when it expires.

How to tell if your propane tank is Expired

Want to tell if your propane gas is expired? Don’t look for its expiry date; manufacturers don’t provide that. Instead, check out for the cylinder manufacturing date or when it was requalified. 

This info is usually on the tank’s collar or in some tanks around the handle area. Usually, it’s in a 4-number format whereby the first two represent the month while the others are for the year of manufacture/requalification.

For instance, take a tank with a 05/20 manufacture date. It means that the cylinder was manufactured in May 2020. Hence, to identify when it’s due for expiry, add 12 years to this date. In the case of this tank, it’ll expire on May 2032.

How to read the markings on a propane tank

Sometimes, it’s not easy to decipher the dates on propane tanks, as we’ve explained above. Why? You may encounter a scenario where there are other letters, which may confuse you about how to tell what they represent. 

First, confirm the dates provided in a four-number format with a dash separating two numbers from the rest. This is the manufacturing date, and it captures the month and year of manufacture, respectively. 

But this is not the only information on the tank. The other data, usually in numbers and letters, include: 

  • Water content (Usually abbreviated WC)
  • Tank Serial Number
  • Tare Weight (Commonly abbreviated TW)

So you must understand how to separate the manufacture date from these specs as they are also commonly on the tank’s collar.

What does the E after Manufacturing Date mean?

You have probably encountered a Tank with an inscription that reads something like this: 

05-12 E. It means that this is a requalified/recertified tank. Hence, it’s already past its expiration date but has been passed to operate for another five years. 

Note that the recertification has to be done by a qualified inspector- who, in most cases, is the gas supplier or authorized agent.

What should you do if your propane tank is expired?

Simply contact your propane gas supplier for an exchange. The company will provide you with a new tank if the old one is not good enough for further use. But if they still find that it’s still in good condition, it’ll be requalified for another five years of service. You should consider switching propane provider in case they inconveniently handle this situation.

The manufacturer will then dispose of the old tank, ensuring it’s not recirculated again. An out-of-shape tank is a fire and leaking hazard and should be done away with, as keeping it has more downsides. 

It is also likely a wasteful leak hazard to your gas reserves.

Apart from Expiry, What Else Can Prevent A Tank Refill?

Note that any tank past its expiry date cannot be further refilled. Another reason that can prevent this even if your tank is not expired is if it lacks an Overfill Protection Device (OPD). This device is critical in avoiding excessive gas refills, which can also affect the container’s pressure

Again, the supplier will inspect if the tank’s valve and head ring and in working condition. Also, if your tank is too rusty, it will not be refilled as it’s likely to leak or cause fire accidents. If the supplier realizes you don’t meet the above conditions, they’ll offer you a new tank.


Don’t have an expired tank, as its downsides are too many to ignore. Primarily remember that propane gas barely expires. 

Instead, it is the tank that gets out of shape, and this is usually after 12 years. Your gas can stay in good condition for up to three decades, so you must keep changing tanks after the expiration dates. 

Hence, always check out this date as we have advised in the article. Again, Compare Propane got your back anytime you want to get the best supplier deal. Talk to us, and we’ll link you up with the best agent in your locale. 

Ryan McCabe

Ryan McCabe

Ryan is a home and small business energy expert, having overseen retail propane, heating oil, and HVAC services companies. On ComparePropane, Ryan writes about things that people should know when shopping for or using propane in their homes and businesses. 

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