What type of cylinder may not require immediate marking updates?

The correct response indicates that old cylinders built per prior regulations may not require immediate marking updates. This is due to the understanding that when a cylinder is manufactured under older code standards, it may not be subjected to the same strict marking requirements as newer cylinders that are produced under more recent regulations.

As long as the cylinder is still in serviceable condition and meets safety requirements, it is permissible to continue using it without immediately updating its markings. This reflects the transitional nature of regulations, where older cylinders that were compliant at the time of their manufacturing can remain in use even as standards evolve.

Newly manufactured cylinders need to have up-to-date markings that comply with current codes. Likewise, cylinders with expired certifications or those that are frequently used may warrant more immediate attention regarding marking updates as they can impact safety and regulatory compliance.