Factory Mutual creates new sprinkler classifications
Factory Mutual Research Corporation (FMRC) has adopted the following new sprinkler classification system, which it says will help industry avoid potential mistakes in selecting the best technology for a given application or protection requirement.
Control Mode: Density/Area–Sprinkler protection is designed based on a given water density over a specified area of coverage.
–Small orifice
–Standard orifice
–Large orifice
–Extra large orifice (ELO)
–Very extra large orifice (VELO)
–K17
–Extended Coverage:
* Light hazard (upright and pendent)
* Ordinary hazard
Control Mode: Specific Application–Sprinkler protection is designed based on a given number of sprinklers operating at a specified minimum water supply pressure in lieu of, or in addition to, density/area requirements.
–Large drop
–Extended coverage:
* Light hazard (sidewall)
–K17
–Cooling tower
–Rack storage
Sprinklers in the above two categories prewet combustibles surrounding the actual fire area to limit the fire`s size, cool the roof area directly over the fire to prevent structural failure, and cool the roof area more remote from the actual fire to prevent too many sprinklers from opening and overtaking the water supply.
Suppression Mode (ESFR)–Sprinkler protection is designed based on a given number of sprinklers operating at a specified minimum water supply pressure. Only sprinklers directly over the fire will operate. By operating early in the fire`s development and by discharging large amounts of water with high momentum to penetrate the fire plume, the fire is suppressed.
–K14.0
–K25.2
Residential–FMRC has not approved any residential sprinklers to date.
