What is the outlet pressure in older buildings that do not have a pressure restriction?

In older buildings that do not have a pressure restriction, it is common for the outlet pressure to be in excess of 300 psi. This occurs due to the higher water supply pressures typically found in older municipal systems, which were designed to meet the demands of fire suppression and other uses. These systems may not have modern pressure regulation mechanisms that are more frequently installed in newer buildings to ensure safe and manageable water supply pressures.

Consequently, the lack of pressure-restricting devices can lead to significantly elevated outlet pressures that exceed 300 psi, creating potential risks for plumbing systems and fire suppression equipment. Understanding these dynamics is crucial for firefighters and other emergency responders as they plan their operations and assess water supply capabilities during incidents.