How to check the date of a Co2 or HPA Compressed air tank.
Paintball air tanks are required by the government to be hydrostatic tested every few years to ensure they are structurally sound and safe for use. The life of air bottles used for paintball purposes can be measured by their hydro test date. Most modern air bottles must be tested every five years. The date at which this must happen can be determined by checking the bottle for information printed on it or stamped into it. CO2 bottles and aluminum compressed air tanks have a date, in month and year, stamped into them near the valve at the top, while an information label is printed into the side of each carbon fiber compressed air bottle, also with a month and year. Hydro testing must be performed within five years from the date found on the bottle. Once tested, the bottles will either be re-certified for another five years of use, or will be rendered unusable should a reason be found not to approve them such as visible damaged.
Can you continue to hydro test tanks?
Depending on the type of tank that you have determines how many times your bottle can be tested if it can be tested at all. While Co2 bottles typically are difficult to find a place to retest them, it is usually less expensive to purchase a new Co2 bottle rather than to have it retested. If you have an aluminum or steel tank, it can be retested until it fails, so it does not have a "lifespan." If you have a carbon fiber or composite tank, it does have a 15 year lifespan, so you can have it tested as required until it reaches 15 years old, then it is dead forever and can not be re-certified.