1¾" Attack Line
FHP ReferenceCommon flow150 GPM
Typical NPCheck nozzle model (50/75/100 psi)
Friction loss~34.9 psi / 100′ at 150 GPM (C=15.5)
C≈15.5 (IFSTA). Formula gives ~35 psi/100′ at 150 GPM. Modern hose often shows lower (15–25 psi) — verify with manufacturer data and department SOG.
General ref · IFSTA Pump Operator Handbook · verified 2026-08 2½" Supply/Attack Line
FHP ReferenceCommon flow250 GPM
Friction loss~12.5 psi / 100′ at 250 GPM
C factor≈ 2 (2½", IFSTA)
FL = C×Q²×L, C≈2 (IFSTA). At 250 GPM: 2 × 2.5² × 1 = 12.5 psi/100′. Actual varies by hose construction — verify before relying on a number.
General ref · IFSTA Pump Operator Handbook · verified 2026-08