With sprinkler systems still in use for many larger applications, Fire Chief Equipment offers engineered pre-action sprinkler systems. Unlike the more common dry-pipe sprinkler system, where the water is held back by a compressed gas pocket inside the pipe, a pre-action system is regulated by an electronically controlled release valve and several optional 'interlocking' safety mechanisms. These features make pre-action sprinklers much more reliable than dry-pipe systems and virtually eliminates the possiblity of an accidental release. Pre-action systems are typically used to protect:

• Cold storage facilities
• Power plants
• Aircraft hangars
• Chemical storage facilities
• Data storage facilities
• Computer operations

Below is a great diagram of a pre-action system.