stupid HPA tank question

[nighthunter]

Okay, so I know that HPA and Co2 tanks need to be tested every 3-5 years depending on construction, and how to find the test date.
I remember hearing that tanks smaller than 2" in diameter don't need to be retested? is that true? If so, does the tank's material (steel, aluminum, carbon fiber, fiberglass) have any bearing on this rule? If it makes any difference, I live in the USA.

[Shaftski]

https://www.mcarterbrown.com/forum/paintball-news-aa/ask-the-experts/178992-2x2-rule-sticky-pinned

[XEMON]

The "2in rule" application will depend on which application with DOT the manufacturer pay for.
The tank under 2" that are exempt from hydro are classified as "testing tanks" instead of the regular "storage tank"

If you are asking about the carbon fiber FS tank, it is NOT exempt ... I checked with FS and confirmed it needs hydro like every other carbon fiber wrapped tanks.

Like i said, it all comes down to the DOT number stamped on the tank.

[XEMON]

When I contacted FS they were not able to give me a definite answer on that 🤯
They said every 5 years and said not sure about life be "should" be ok ... So ... Who knows at this point ...

[nerdcore]

This place is under the impression that UN ISO tanks still get retired after 15 yrs. https://www.velocitypaintball.com/2016/03/dot-vs-iso

It's hard to get a clear answer, but my current assumption is that the lifespan of the tank will fall within the rules for the country the tank has been approved for. If it's approved for sale and use in the USA, it's got 15 yrs. Being either DOT or ISO certified seems to only designate who certified the tank at birth. After that, it's house rules.

[Grendel]

Per US D.O.T. 49 CFR 1XX documentation "Unlimited Life" = 38 years. Why they call it "unlimited' when it actually has a limit is typical governmental bureaucratic speak. I'm guessing they originally said unlimited in reference to realistic expectancy that a pressure vessel would be used then someone pushed back and instead of changing their documentation that just made a bureaucratic definition to cover themselves.