Originally Posted by dmako
I called a few places and they all swap. One place will fill but even without certification it would take 1-2 weeks.
Wow. That's just greasy. Certifying the tank is not to protect the company that fills it. It's to protect you from a catastrophic failure of the bottle. Tanks go bad. Not CO2.
Tanks expand and contract under the pressure of the gas, over time this can weaken the walls. They do fail occasionally.