Pressurized gas in the cylinder forces chemicals out to extinguish fire. Underwriters need to ensure that the pressure is maintained at the proper level.
An activating device sets off the system in the event of fire. The fusible link is the most common device and requires replacement annually. The system also needs a manual device to activate it in case the automatic device fails. The manual pull should be well marked and located near an exit.
Piping and nozzles
Dry and wet extinguishing systems require different kinds of piping and nozzles. Dry nozzles are larger and usually capped to protect them from grease. Wet nozzles are small and may have a plastic cap on them. Nozzles must point at the equipment they‘re designed to protect.
Automatic fuel shut-off
When the extinguishing system activates, it should automatically shut off the gas or electricity providing heat for cooking.