Technical data

1.1.1 Model DDX Wet Pilot Line Trim
A wet pilot line is a non-electrical type of detection/release system that can be used in conditioned
(i.e. freeze protected) areas. Closed sprinklers or fixed-temperature-release pilot line detectors are
installed throughout the protected area on small diameter piping that contains water under pressure.
The wet pilot line is an extension of the Model DDX Deluge Valve push-rod chamber. Upon activation of
a pilot line sprinkler or pilot line detector, pressure is released from the pilot line and push-rod chamber
allowing the Model DDX Deluge Valve to open and deliver water to the open sprinklers, nozzles, or
other discharge devices in the protected area. Alarm devices are activated upon the flow of water into
the sprinkler system piping. Wet pilot trim is the basis on which dry pilot line and electrical actuation
systems are built; additional components are added to the wet pilot trim for each of these systems. It
is important to note that the length and height of wet pilot lines may be limited by the available system
water pressure (see bulletins referenced below).
Approvals and technical data for Model DDX wet pilot deluge systems can be found on Reliable Auto-
matic Sprinkler Company Bulletins 516 through 519.
4.
Figure 2