A wet sprinkler system protecting freezers may have an antifreeze loop or dry heads.
An antifreeze loop is filled with antifreeze, but hopefully not automotive antifreeze. Automotive antifreeze is flammable. A non-flammable antifreeze is used, and there are supposed to be check valves and backflow valves to prevent the antifreeze from getting into the potable water.
Dry heads are charged with nitrogen and used in freezers, coolers and other areas that are subjected to freezing. When the sprinkler head is subjected to high temperatures, the fusible link or glass bulb activates and the nitrogen is realesed, then a plug is pushed out by the water pressure and water flows.
Sprinklers have a success rate of approximately 93%. The failure rate is usually attributed to lack of proper mainentenance.
Hollywood shows all the sprinklers going off at the same time because is makes for ticket sales, similar to the big sparks when electrical someone plugs in an extension cord. Not based on fact, but is impressive, never mind the false impressions of the general public.
Fireguy
