Stormin Mormon wrote:
Please post evidence. I've never seen such.

"Deluge systems are connected to a water supply through a deluge valve that
is opened by the operation of a smoke or heat detection system. The
detection system is installed in the same area as the sprinklers. When the
detection system is activated water discharges through all of the sprinkler
heads in the system. Deluge systems are used in places that are considered
high hazard areas such as power plants, aircraft hangars and chemical
storage or processing facilities. Deluge systems are needed where high
velocity suppression is necessary to prevent fire spread."

http://www.apifiregroup.com/firesprinkler/deluge.html

or

http://www.tpub.com/content/construc...s/14259_71.htm