At what psi is the water supply usually set for effective foam generation?

Effective foam generation typically requires a water supply pressure that ensures proper mixing of the foam concentrate and the water, as well as sufficient discharge velocity from the nozzle. A pressure setting of 200 psi is generally optimal for achieving this balance. At 200 psi, firefighters can create a consistent and effective foam blanket, which is crucial for suppressing flammable liquid fires and providing thermal protection.

Lower pressures, such as 100 psi, could lead to inadequate foam generation and coverage, while pressures that are too high, like 250 psi, might cause excessive misting of the foam and reduced stability, ultimately hindering its effectiveness. Thus, 200 psi is recognized as the standard for achieving the desired performance in foam operations, ensuring that the foam maintains its required characteristics for fire suppression.