Definition
Common K-factors include K57 (K4.0) for residential, K80 (K5.6) for OH1 commercial, K115 (K8.0) for OH2/OH3, K161 (K11.2) for HHP, and K360 (K25.2) for ESFR. Units differ by region — metric uses L/min/bar^0.5, imperial uses gpm/psi^0.5. Picking the right K-factor is the first hydraulic decision: a too-low K forces excessive pump pressure; too high reduces coverage flexibility.
Referenced in
- EN 12845
- NFPA 13