"Stormin Mormon" wrote in message
...
Please post evidence. I've never seen such.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
.


"HeyBub" wrote in message
...

In some sprinkler systems, when one goes off, they all go
off. Better to be
wet than blown into the ocean.


Deluge systems
"Deluge" systems are systems that have open sprinklers, i.e. the heat
sensing operating element is removed or specifically designed open
sprinklers, so that all sprinklers connected to the water piping system are
open. These systems are used for special hazards where rapid fire spread is
a concern, as they provide a simultaneous application of water over the
entire hazard. They are commonly seen as preventative measures to prevent
egress of fire from an external source (eg hi-rise windows, warehouse bay
entries, over openings in a fire-rated wall)

Water is not present in the piping until the system operates. Because the
sprinkler orifices are open, the piping is at atmospheric pressure. To
prevent the water supply pressure from forcing water into the piping, a
deluge valve is used in the water supply connection, which is a mechanically
latched valve. It is a non-resetting valve, and stays open once tripped.

Because the heat sensing elements present in the automatic sprinklers have
been removed (resulting in open sprinklers), the deluge valve must be opened
as signaled by a specialized fire alarm system. The type of fire alarm
initiating device is selected mainly based on the hazard (e.g., smoke
detectors, heat detectors, or optical flame detectors). The initiation
device signals the fire alarm panel, which in turn signals the deluge valve
to open. Activation can also be manual, depending on the system goals.
Manual activation is usually via an electric or pneumatic fire alarm pull
station, which signals the fire alarm panel, which in turn signals the
deluge valve to open.

Operation - Activation of a fire alarm initiating device, or a manual pull
station, signals the fire alarm panel, which in turn signals the deluge
valve to open, allowing water to enter the piping system. Water flows from
all sprinklers simultaneously.