Approximately how many seconds after transfilling will the pressure between the SCBA cylinders equalize?

The correct choice indicates that it takes about 60 seconds for the pressure between the SCBA cylinders to equalize after transfilling. This duration typically ensures that the gas transfers effectively, allowing for a balance in pressure between the full and the depleted cylinder.

During the transfilling process, pressurized air flows from the fuller cylinder to the lower-pressure one, and this process requires a certain amount of time for the gas to stabilize due to the laws of physics governing gas flow and pressure equalization. A one-minute timeframe is generally considered a safe and effective estimate for this process, ensuring that both cylinders reach a more uniform pressure without any abrupt changes that could potentially lead to safety concerns or inefficiencies.

In SCBA operations, understanding the timing involved in transfilling is crucial for personnel to manage their air supplies safely and effectively, especially in emergency situations where air supply could be critical.