Why and How Paintball Tanks Need to Be Re-Hydrotested


If you are a warrior of paintball, then you know searching online can be frustrating when determining what your paintball tank needs to stay in the best condition. There are many markings on your tank and forums that go on and on. Grab your tank and just read this article because in a few moments you’ll be an expert at why and how your tank needs to be re-hydrotested!

Paintball tanks need to be re-hydrotested because the tank expires about every five years, and you want to be sure the tank’s pressure doesn’t empty out. To have your tank re-hydrotested, you should take it to a paintball gun professional.

Working with a tank that is being run at high pressures can be very dangerous if it’s not properly cared for. Hydrotesting is necessary to ensure you’re using a safe piece that’s not structurally deficient. Although a failing tank is rare, if this is a sport you love, or you have a paintball tank – you need to know this.

Why Paintball Tanks Need to Be Re-Hydrotested:

The why part of this question is where we’ll begin. Understanding what is happening inside of your tank is important to understand how it will be re-hydrotested.

Paintball tanks are no different than any other high-pressure vessel. A hydrotest will detect what needs some TLC or any potential issues. Luckily for you, modern tanks are very well made and manufactured with integrity more times than not.

It is very rare because of this that we have a tank fail, and it really only needs to be looked at every 5-15 years depending on the date on your tank.

The reason for the re-hydrotesting is because of the amount of pressure going on in the tank. Imagine a tightly compact balloon that’s inside of the metal tank. It’s a balloon that can hold three times the amount of air it should be rated for. This is not uncommon in paintball tanks, so it’s very pressurized inside the tank.

What if You Don’t Re-Hydrotest a Paintball Tank?

If you don’t hydro-test your tank at all, then first off, you’re not being a responsible owner. You don’t want to over pressurize the tank, or it could blow or simply fail and break. If the tank is out of compliance, you could be taken out of games, and honestly, many fields will simply not let you play.

That’s the way it is, and it’s for your safety. It would be very negligent on their part to allow you to play if they notice that your tank is overdue or outdated. Staying up to date on your hydrotest means your keeping yourself from danger and not putting others in harm’s way as well.

The largest ‘why do it’ reason is not just because you could be banned from games, but you could also face a fine if you’re caught. This is serious and dangerous, so don’t take re-hydrotesting lightly.

It’s also important to note that it is illegal to fill a tank out of the hydro-date. So if the field doesn’t want to fill your tank because it’s too far out of the expiration date, don’t push them. Penalties will include a severe fine or worse, and you could put the game’s field company in liability as well if they allow you to play with an expired tank.

How Paintball Tanks Need to Be Re-Hydrotested:

Understanding what is actually happening is very simple. You’re essentially filling the tank with a higher-pressure level than it is rated to handle. Like pressure testing it to be sure it can deal without failing. If it can withstand the pressure without failing, it passes and is valid for another three to five years.

If, however, your tank fails the pressure test. You will probably have to purchase a new tank.

The how portion of this question is based on the two expiration dates on your tank:

  • The first is the re-hydrotesting date which will be every 5 years from the date on the tank.
  • The second date is around 15 years and signifies when the tank will expire completely.

Pay attention to both dates and be sure you’re keeping up on your tank’s condition and lifespan. Play fields can not only remove you, but it’s not unheard of that you will be banned from fields for life. They have the right to do this if you’re not being responsible and are fully entitled to ban you.

The hydro test is simple. You will submerge the tank in hot water and see how much pressure the tank can withstand without compromising it.

You can technically do this at home, but it’s just easier if you take it to a professional, I will explain after I tell you the steps you need to take to hydrotest your own tank.

Here are the steps to re-hydrotest your own tank:

  1. Set the regulator aside. It is not needed for the hydrotest.
  2. Check the REE on the tank or research if you can’t find it. The REE is the Rejection Elastic Expansion. This will be on your tank and look something like “15.2cc.” You need to know this before beginning because it means your tank can expand up to 15.2 cubic centimeters and pass.
  3. Inspect the tank first to be sure nothing is damaged or looks faulty. If it’s damaged, your tank has immediately failed the inspection. It is very important that you note the threading that holds it all together because the threading keeps the regulator secured to the tank.
  4. Check the inside of the tank now that you’ve inspected the outside. You’re keeping your eyes peeled for signs of corrosion or other damage to the inside. If there are any defects, the tank fails.
  5. Once you’ve flown past the visual checkmarks, the actual hydrotest begins! First, you’ll want to fill the tank with water.
  6. Now place the filled tank of water in a pressure vessel which is also filled with water. The reasoning is that if your tank blows, you’ve at least got it in a pressure bucket or something safe for it to blow in instead of just open space. Be sure you have the top of the tank connected to the hose on the top lid of the pressure vessel. If it’s all connected, the top pressure vessel is closed and secure.
  7. If it’s made it this far, no high-pressure water will be pumped into the tank. This will see how much it expands or if it can withstand the pressure. Again, it should be able to take around three times as much pressure as its size appears. If you see it expanding too much or seemingly weakening to the pressure, this is a bad sign.
  8. The less your tank is expanding the better. This is a good sign and means your tank is strong.
  9. Reference again your cc number which I explained in step 2. If your tank expands beyond that REE number, your tank fails the hydrotest.
  10. If your tank has passed the visual test, pressure test, and is staying strong under pressure – then your paintball tank has passed the hydrotest! Congratulations!

The only thing to do now is to get the expiration date updated. This is why I believe it’s simpler to take it to a professional in the first place because the date will need to be changed after the hydrotest regardless.

The ‘how’ portion doesn’t need to be complicated – If you’re unsure, take it to a professional.

Short Youtube video about the process of hydrotesting paintball tanks.

They know how to properly hydrotest your machine and will get it returned to you with a new date of expiration. Have this done properly and be responsible for the dates. If you need to set a reminder in your Google calendar for 5 years from now because you don’t trust yourself to remember, do it. It could make all the difference in you having a functional and safe tank to use.

Do it right and bring it to the professionals, so you have no fines or illegal activity to worry about.

The Cost of Re-Hydrotesting:

The prices will vary depending on what model and where you’re purchasing it. Metal cylinders are different and come with varying rules and regulations.

Most hydrotesters will charge between $30-150 depending on the location and quality of machinery.

The price of a new hydro is around the same price as a brand-new cylinder. It’s simply what they cost, but it is necessary. Price will also depend on your manufacturer and the quality of your paintball gun.

If your tank fails, you won’t get it returned back to you, and the hydrotester will disable the bottle by drilling a hole in it to render it useless. They don’t want to be liable for this as it could result in fines and is not safe.

Paintballing is certainly not as expensive of a sport as golfing, diving, bicycling, or hobbies like photography which can cost thousands to get into. As far as hobbies go, it’s quite affordable, and the hydrotest is less of a burden to your wallet and more of a minor inconvenience of time.

Don’t let money or time get in the way of you being a responsible paintball tank owner or the consequences will be far worse than just getting it in for a simple hydrotest.

Understanding When to Re-Hydrotest:

Another way to check your date and understand when it is time is to search the DOT-SP number on your tank. That’s almost like a product number or serial number and will indicate if it’s time for your re-hydrotesting.

Sizes and variations that you should be aware of include:

  • For a Co2 Cylinder, you’ll want to throw it out every five years for a new one.
  • Aluminum tanks may last upwards of 20-24 years.
  • Anything around 2 Inches in Diameter or 2 feet in length will go under what players call the ‘2×2 rule.’ What this means is that hydro-exempt and re-hydrotesting it may not be required. You’ll need to research based on your own model, but it’s something to be aware of.
  • Most cylinders have the 15-year life span from their original date, but check yours to be sure it’s up to modern standards (sometimes the re-hydrotesting date is every three years instead of every five).
  • Some tanks may not have a lifespan or expiration date printed on them at all. To which you may be very confused and not know what to do. In this case, find your DOT information which is like a series stamp or model number. The laws and permits will depend on this but are constantly evolving.

With all of these variations – you really need to be certain about your specific piece.

DOT rules are changed if a company doesn’t renew the series or the DOT changes the actual rule or law. Research your own specific model and be aware that what works for your buddies’ tank may not work for yours.

The professionals will also place the date under a layer of epoxy for you to prove it’s been tested and passed. If you have a metal or aluminum tank, they will actually stamp the date directly onto your metal tank like an engraving.

For example, your tank may now say ’07 TUV1 17,’ in which case this would be the model updated in July of 2017. Since this tank is a model that is good for five years, we know that the next hydro-testing will be in July of 2022.

Other Potential Dangers to Your Paintball Tank:

Besides the hydrotesting and pressure, you’ll want to be aware of other issues that can hurt your tank and be dangerous.

During the sport, you’re running around and jumping off of high beams, diving to the ground and really ramming into the elements like sticks, trunks and defense lines. Your tank will take some bruising from this and is usually quite durable. Just because it is uncommon for them to crack, doesn’t mean they’re absolutely indestructible.

If you just have small lines from wear and tear, this is nothing to concern yourself with. This is very normal and is just paint chipping. The time to be concerned is when you see deep cuts that are affecting the actual structure of your paintball gun and or the tank.

If you’re not sure if you’ve got a simple marking or something that could be dangerous, run it by the shop or a professional to confirm. They can check it quickly to save you the worry over using a defective machine.

A pro tip to keep your paintball gun in the best condition is to purchase a tank cover for it. It’s worth the small investment and can help your aim too.

One final danger to consider is that most tanks do not fail their hydrotest, but a common reason that they do fail is that the paintballer damaged the threading when attempting to test. Yet another reason to take it to your local paintball shop and see where they recommend hydrotesting.

Be sure it’s done the right way by people who know what they’re doing, and you shouldn’t have any issue.

Lastly, Is My Tank Worth Hydrotesting?

I don’t like to recommend being wasteful but to be completely honest, not all tanks are worth the energy and finances to re-hydrotest.

You can take spare parts back to the distributor and see if they have the means of recycling the materials, so they don’t go to waste. But oftentimes, the cost to re-hydrotest is beyond what you paid for the piece in the first place. You don’t want to invest more and more into a cheap tank.

If, however, you have a high-quality tank that is Co2 or HPA Steel, it is worth it to hydrotest your tank and stay up to date on it. It will really depend on how attached you are to your machinery and if it feels worth the time and energy to you.

If your tank is scratched up and looks to be on its last leg of life anyways, go ahead and invest in a new updated tank.  If you fail the test, you’ll be buying a new one regardless. So why not just purchase a new paintball gun and tank every 5 years or so if you’re keeping it economical anyways.

In many cases, it may just be $10-20 more to get an entirely updated and fresh tank. This is worth it to me, but that will depend on your personal preference and what you want to spend on it.

If you’re concerned about cost, sell your old one and use that money to purchase a new one. Go on eBay or Amazon, and there are tons of buyers interested in discounted priced pieces. You may only get a small portion of what you paid for it, but it will supplement the cost of your new one.

Another way to see it is – you may not be playing in 15 years. Take it every half-decade for now and see how you feel about paintball in the future. If you’re a master that has been playing for all their life, you already know the answer to how much you want to invest in your passion.

Commit what feels right financially and enjoy the game! That’s what it’s all about.

Now that you’re aware of the fines, fees, and rules regarding your tank and it’s hydro-testing – you can be even more focused on what you need to do in the arena. Happy gaming!

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