What is the normal range for the air pressure gauges?

The normal range for air pressure gauges on fire apparatus is commonly set between 100 to 120 psi. This range is crucial for ensuring that the air systems, such as air brakes and other pneumatic systems, function effectively and reliably. Operating within this range helps maintain the optimal performance of the firefighting equipment and ensures safety during operations.

Low air pressure, below 100 psi, might lead to insufficient operation of tools or brakes, potentially creating hazards during firefighting situations or while driving. Conversely, pressures exceeding 120 psi could indicate a malfunction or result in unnecessary strain on the system, which could lead to equipment failure. Therefore, the 100 to 120 psi range is established based on both safety and functionality, making it the correct answer for normal air pressure gauges in fire apparatus.