What is the friction loss coefficient for 2 ½" hand lines flowing 250 GPM?

The friction loss coefficient is an essential factor in determining the pressure loss due to friction as water flows through hoses. For a 2 ½" hand line flowing at 250 gallons per minute (GPM), the commonly accepted friction loss coefficient is approximately 12 psi. This coefficient is derived from established formulas and empirical data which indicates how much pressure is lost per 100 feet of hose length at that specific flow rate.

When calculating pressure loss in firefighting operations, understanding these coefficients helps in effectively managing the water supply and ensuring adequate pressure reaches the nozzle. A coefficient of 12 psi for a 2 ½" line at 250 GPM reflects the practical considerations seen in the field and aligns with the friction loss models used in training and operations. This allows fire pump operators to make informed decisions regarding hose layouts, pump operations, and overall water supply management during firefighting efforts.