In which circumstance must a sign at a fire department connection specify the required inlet pressure?

The requirement for a sign at a fire department connection to specify the required inlet pressure arises when the system demand pressure exceeds 150 PSI. This is crucial for ensuring the safety and effectiveness of fire suppression efforts. When the pressure exceeds this threshold, firefighters need clear and specific information about the inlet pressure to operate their equipment correctly and safely. This knowledge helps prevent issues such as pump malfunction or ineffective firefighting measures that can arise from incorrect pressure assumptions.

In cases where the demand pressure is below 150 PSI, the expectations and capabilities of the firefighting equipment may not necessitate such explicit markings, as they typically operate effectively within standard pressure ranges without needing specific guidance. Thus, the emphasis on marking the inlet pressure is a critical safety measure in high-pressure situations to ensure that fire personnel can respond optimally during emergencies.