Technical data

1.2.4 Model H Single Interlock Preaction System
The Reliable Model H 1-1/2” (40mm) Single Interlock Preaction system is an electrically actuated sys-
tem that utilizes a normally closed, quick-opening hydraulically-operated diaphragm actuated solenoid
as the main system control valve. When in the normal condition (de-energized) water pressure is held
at the solenoid valve inlet. Upon receipt of a signal from the electric detection system, the release
panel opens (energizes) the solenoid valve allowing water to flow to fill the piping network essentially
converting the system into a wet pipe system. Alarm devices are activated by the System Sensor
Model EPS 10-1 pressure switch (provided with assembly) upon the flow of water into the sprinkler
system piping. In the event the fire continues to grow, individual fire sprinklers in the protected area will
be activated similar to a wet pipe system. For supervised systems (required when there are more than
20 sprinklers), pneumatic pressure can be provided from a compressor, plant air system, or nitrogen
cylinders. Pneumatic pressure is monitored by a pressure switch that will notify the owner in the event
of falling pressure due to sprinkler damage, pipe damage, or failure of the compressed gas system.
The Reliable Model B-SI and Model C-SI Air Compressor Panels are specifically designed for single
interlock preaction systems up to 200 gallon capacity and incorporate an air compressor, regulator,
pressure switch, and output relays in a convenient wall mount cabinet (see section 2.3.1).
Approvals and technical data for the Model H Single Interlock Preaction System can be found on Reli-
able Automatic Sprinkler Company Bulletin 719 (supervised) and 721 (non-supervised).
12.
Figure 10