Fire protection glossary

Plain-language glossary of fire sprinkler terms: ESFR, K-factor, OH1–4, HHS, pre-action, deluge, VESDA, IG-541 and more — referenced to EN 12845 and NFPA 13.

Sprinkler heads

Control Mode Specific Application(CMSA)
High K-factor control-mode sprinklers designed for specific storage applications.
Early Suppression Fast Response(ESFR)
High K-factor sprinkler designed to suppress (not just control) high-piled storage fires by delivering a large quantity of water early in the fire cycle.
In-rack sprinkler
Sprinklers installed within storage racks to control fire growth in concealed flue spaces.
K-factor
Discharge coefficient that links flow (Q) and pressure (P) at a sprinkler head: Q = K·√P.
Pendent sprinkler
Sprinkler head installed pointing downward, with the deflector below the orifice.
Quick-response sprinkler(QR)
Sprinkler with a fast-acting thermal element (RTI < 50) for early activation.
Sidewall sprinkler
Wall-mounted sprinkler discharging horizontally across the room.
Upright sprinkler
Sprinkler installed pointing upward, used where piping is exposed.

System types

Hazard classification

Hydraulics

Detection

VESDA / aspirating smoke detection(VESDA / ASD)
Very Early Smoke Detection Apparatus — actively sampled air analysed for combustion particles.

Suppression

Standards

Regulators

CNBOP-PIB
Polish national fire research institute — issues product certificates of admittance.

Components