Is the date stamped on the bottle the expiration date or the test date? I have a 20lb steel bottle with a bunch of dates on it dating back to the 1970’s, the latest date on it is 08/03 (assuming August, 2003). Inbetween the 08 and the 03 are little tiny numbers 08 and 13. Does this mean the certification was done in August 2003 and that it expires in August 2013?
For some reason I was thinking the certification was 5 years.
I think it is aluminium vs. steel tanks.
Quick call to AirGass will be great source of this info.