Preaction Sprinkler System
A Preaction Sprinkler System is a system which employs automatic and closed-type sprinkler heads connected to a piping system that contains air (either pressurized or non-pressurized), with a supplemental system of detection serving the same area as the sprinklers. The systems are typically used in applications where the accidental discharge of water would be catastrophic to the usage of occupancy.
Preaction Sprinkler Systems are similar to Dry Pipe Systems in that the water is kept from entering the piping valve, in the case a preaction valve. This valve is held closed electrically, only being released by the activation of the detection system (heat or smoke detectors mainly) when an electrical signal is sent to the releasing solenoid valve. The water then fills the pipe, ready for the activation of the sprinkler heads. Preaction systems can be arranged to be activated by only one detection device type, or many.
A preaction system can also be combined with a Dry-Pipe System, for use in areas that are unheated, or areas where the occupant requires the water not enter the system prior to the activation of a sprinkler heads. Protection systems can be arranged to be activated by only one detection device type, or many.
A preaction system can also be combined with a Dry-Pipe system, for use in areas that are unheated, or areas where the occupant requires that water not enter the system prior to the activation of a sprinkler. This is called a Double-Interlocked preaction system. This system functions much like a dry-pipe system, however the release water also depends on the activation of the detection devices.
Common installations include computer rooms, process control rooms, data storage and telecommunications rooms.