In Norway where I live, tanks can be inspected, stamped, and approved for industrial use, for 5 years. That means they are not approved for diving, or used for the intention as breathing air, but for industrial work. You can then fill them at any diving shop, without the need for a diver sertificate (as long as the aproved date is not overdue). Filling them at fire stations, all depends on the local station itself. The local fire department where I live, would not fill tanks. But if I drove 30 minutes to the neighbour town, they would fill them for aprox a 5 dollar fee.