We are often asked “How do I know when my tank needs to be hydrotested?” Searching online can be frustrating, as you try to decipher markings on your tank. Instead of searching and reading countless forums, grab your paintball tank and keep on reading. In a few short minutes you will know exactly when your paintball tank needs to be re-hydrotested!

First, a bit about paintball tanks and hydro testing. Paintball high pressure air tanks will need to be hydro tested every 3 or 5 years depending on the bottle manufacturer. The date of manufacture will be marked on the tank, and it is your responsibility to have it re-hydrotested when your tank expires.  Hydro testing involves pressurizing your tank to a level much higher than the tank is rated to handle. If your tank is able to withstand the pressure without failing, it will pass the test and be valid for another 3 to 5 years. If it fails, you will need to purchase a new tank.

If your tank passes the hydro test, the testing facility will apply a new month and year tag to your tank, usually protected under a layer of epoxy, in order to demonstrate that the tank has been tested, and has passed. This new date stamp will act as the new point of reference to be used for testing the tank again after the next 3 or 5 year period has expired.

It is illegal to fill a tank that is out of hydro-date, so if your local field refuses to fill your out-of-date tank, do not give them a hard time – the penalties for filling an expired tank are severe, and not only will the field be held responsible, but so will the individual who fills the tank.

Below is a picture of the manufacturing date of a Guardian 48/3000 compressed air tank. You will notice that this manufacturing date is stamped directly onto the bottle. The majority of steel or aluminium tanks are stamped in this manner.
The manufacturing date is visible at the end of the stamp as 07 TUV1 13. The numbers that we care about in this case are 07 and 13. The first number indicates the month the tank was manufactured, and the second represents the last two digits of the year. This informs us that this tank was manufactured on the 7th month of 2013, or July 2013. Since this tank is valid for 5 years, it will have to be retested in July of 2018.


The picture above is taken from a Guardian 48/4500 Carbon Fiber tank. It shares the same manufacture date as the aluminium tank, but looks different. Carbon Fiber tanks will have their hydro dates and information on a label underneath the clear coat of the tank, instead of stamped onto the tank itself. You will also notice that it clearly states the tank is good for 5 years from the original hydro date, and has a total lifespan of 15 years.


Are any tanks exempt from being re-hydrotested? Yes. Tanks that have an external diameter of 5cm or less, and are less than 61cm  long are exempt from being re-hydrotested. Tanks generally included in this category are 13/3000 compressed air tanks and small 3.5oz CO2 tanks.


Some paintball tanks will not have the TUV1 marking in between the month and year, and will instead use an arrow, “C”, or some other symbol. Below you can see some of the common manufacturing symbols that you will come across.
The above tank uses an Arrow to separate the month and year, and has a manufacture date of March 2007. It needed to be re-hydrotested in March, 2012.


This carbon fiber tank uses a “CL” to separate the month and year. This tank was manufactured in January, 2004.