[TheTJ]

Plasma, you may want to check the "recert date" section. If memory serves me correctly... metallic tanks are hydro test every 5 years and carbon fiber are hydro test every 3. This is because carbon fiber has a much better chance of becoming damaged than metallic tanks over the course of usage.

 

[TheTJ]

I know for sure carbon fiber is 5 years. Don't know about aluminum/steel. I think it is 5 also.

Not all carbon fiber. It depends on the maker. Some of them are 3 years, some are 5 years. This also dictates how long the tank may remain in use before it must be discarded (as in can no longer be hydro tested)

My Pure Energy tank is every 3 years:



And my Crossfire tank is every 5 years:

 

[TheTJ]

My PE tank's in-service date is from 2007 so they may have done away with 3 year tanks now... But that would be a shame because according to the DOT rules, 3 year tanks are good for up to 18 years from the in service date whereas 5 year tanks are only good up to 15 years.