Nozzle / Fire-Stream Reaction Force
Nozzle reaction force for a smooth-bore (1.57 d^2 NP) or fog (0.0505 Q sqrt(NP)) stream.
Example
You enter
- Nozzle type smooth
- Bore diameter (in) 1
- Nozzle pressure (psi) 50
You get
- Nozzle reaction 78.5 lb
Checked against published worked examples from: IFSTA Pumping Apparatus Driver/Operator (nozzle reaction).
Details, formula, and sources
ScopeWith a staffing note vs. the ~60 / ~75 lb thresholds. Per IFSTA Pumping Apparatus Driver/Operator.
Formula or tableSmooth bore: NR = 1.57 * d^2 * NP. Fog: NR = 0.0505 * Q * sqrt(NP). NR in lb, d in inches, NP in psi, Q in gpm.
Source and editionIFSTA Pumping Apparatus Driver/Operator nozzle-reaction formulas, by name.
Free accessIFSTA licensed; the nozzle-reaction formulas are public and reproduced in pump-operations curricula.
What governsEstimate. AHJ and licensed fire protection engineer govern.
API field namesnozzle_type, bore_in, nozzle_pressure_psi, reaction_lb
- Staffing thresholds ~60 lb one-firefighter, ~75 lb hose-team (advisory; AHJ and fire-officer judgment govern)IFSTA pump-operations practice