When should a tank be labeled for overfilling?

A tank should be labeled for overfilling when it has the plus sign marking. This marking indicates that the tank is certified for a higher filling pressure than its standard service pressure, allowing it to be filled to 10 percent over its rated capacity. This means that a tank with this marking can safely hold more gas than its nominal specification, as long as the manufacturer’s guidelines are followed. This capability can be beneficial in situations requiring additional gas capacity without the need for additional tanks. Proper labeling helps ensure that everyone handling the tank is aware of its overfill potential and can follow safe practices when filling and using the tank.

In contrast, newer model tanks may not necessarily have overfilling capabilities unless they also display the appropriate certifications. A tank with a history of leaks requires caution but does not automatically signify overfilling approval. Finally, while a tank rated for a higher pressure may suggest it has some advanced manufacturing standards, it does not guarantee it has the plus sign marking that specifically indicates the ability to safely overfill.