What is the appropriate pressure for a smooth bore nozzle used with a master stream?

The appropriate pressure for a smooth bore nozzle used with a master stream is typically around 80 psi. This pressure setting has been widely accepted in fire service practices because it balances effective water flow and reach with manageable nozzle handling for firefighters.

At 80 psi, the water is ejected from the nozzle with sufficient velocity to create a powerful stream capable of reaching significant heights and distances, allowing for effective firefighting operations, especially in large-scale incidents where master streams are deployed. This pressure also ensures that the stream maintains its consistency and penetration characteristics, which are crucial for efficiently cooling down hot spots and suppressing fires.

Other pressures, such as 50 psi or 100 psi, may not generate optimal performance from the smooth bore nozzle. A pressure of 150 psi is often too high for most operations involving smooth bore nozzles, which could lead to difficulties in maneuvering the nozzle and increased risk of damage to the equipment or injury to personnel.