Calculate sprinkler flow rate from K-factor and pressure using Q = K * sqrt(P) per NFPA 13.
Input Parameters
Results
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Flow per Sprinkler
gpm
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Total System Flow
gpm
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Min Pressure for 7 psi
psi
Note: NFPA 13 requires a minimum operating pressure of 7 psi at the most remote sprinkler. K-factor is stamped on each sprinkler head and determines flow at a given pressure.
Reference
Q = K × √P
where Q = flow (gpm), K = K-factor (gpm/psi^0.5), P = pressure (psi)
Common K-factors: 2.8 (residential), 5.6 (standard), 8.0 (large orifice), 11.2 (EC), 14.0 (large drop), 16.8 (ESFR), 25.2 (ESFR large)