Which condition signals an immediate action when observed in a cylinder?

A steady white stream from the gauge signals an immediate action when observed in a cylinder because it indicates a potential issue with the gas flow or pressure within the cylinder. This phenomenon can be indicative of a leak or malfunction in the dispensing system, which can lead to dangerous situations such as gas accumulation, fire hazards, or even explosions if not addressed promptly.

In the context of safety protocols, any abnormal visual indication, such as the steady release of gas, requires immediate inspection and corrective measures to ensure that gas is contained properly and to prevent any risk of injury or property damage. Therefore, recognizing and reacting to this condition is critical for maintaining safe operations.

In contrast, while incorrect labeling, visible corrosion, and excessive weight are certainly concerns that should be monitored, they do not typically require the same urgency in immediate response that a steady white stream from the gauge does. Each of those other conditions may indicate a need for further investigation or maintenance but does not represent an acute safety threat in the same way that a gas leak does.