Reliable Sprinkler RELIABLE Single Interlock Preaction System 6103060028 - Manual (Page 6)

Fig. 3
6.
Once the clapper has opened, the lever acts as a
latch, preventing the clapper from returning to the
closed position. Water from the supply flows through
the deluge valve into the system piping. Water also
flows through the deluge valve alarm outlet to the
alarm devices.
After system shutdown, resetting the Model DDX De-
luge Valve is quite simple. Doing so only requires
pushing in and turning the reset knob at the rear of the
valve (see Fig.1). The external reset feature of the
Model DDX Deluge Valve provides a means for sim-
ple, economical system testing, which is one essential
facet of a good maintenance program.
The external reset feature does not, however, elimi-
nate another important facet of good maintenance,
namely, periodic cleaning and inspection of the inter-
nal valve parts. In the event that water builds up inside
the valve due to condensate from the air supply sys-
tem or water left inside from valve system testing, a
drain is available for venting. After closing the main
supply valve, a small valve over the drain cup can be
opened slightly until the water inside the valve body
and the main pipe column has drained. See the sec-
tion titled “Draining Excess/Condensate Water From
System” in this bulletin for the detailed procedure.
The Model B Manual Emergency Station (see Fig. 3)
is also included in the trim set. It consists of an alumi-
num nameplate mechanically attached to a ball valve.
The valve handle in its OFF position is guarded
against accidental turning to the ON position (and
system discharge) by a nylon cable tie provided with
each trim kit. The cable tie is inserted, as shown in Fig.
3, after the system has been restored for operation.
The nylon cable tie is designed to allow, in case of an
emergency, forceful turning of the valve handle to the
ON position. As an alternative to the Model B Hydrau-
lic Manual Emergency Station, the Model A Hydraulic
Manual Emergency Pull Box (see Reliable Bulletin
506) is also available and can be provided as an op-
tion.
Whenever ambient temperature conditions are high,
the water temperature in the Model DDX Deluge
Valve’s pushrod chamber could possibly increase,
thereby increasing the pressure in the chamber to val-
ues exceeding the rated pressure of the system. In an
indoor installation where standard room temperatures
are exceeded, a pressure relief kit may be needed.
Pressure relief kit, P/N 6503050001, can be installed
into the pushrod chamber’s releasing line to limit the
pressure to 175 psi (12,1 bar).
System Operation
To fully operate a Reliable Single Interlock Preaction Sys-
tem, two independent events must coexist before water flow
will occur.
One electrical detector (two detectors in a
cross-zoned system) must activate and a sprinkler head
must open. Operation of either one of these items will only
cause an alarm to annunciate, but will not cause water to
discharge from the sprinkler system piping.
When set correctly for service, the Model DDX Deluge
Valve is hydraulically established to withhold the supply wa-
ter from the sprinkler system piping. The Reliable Model
DDX Deluge Valve is shown in both closed and open posi-
tions in Fig.1. In the closed position, the supply pressure
acts on the underside of the clapper and also on the push
rod through the push rod chamber’s inlet restriction. The re-
sultant force due to the supply pressure acting on the push
rod is multiplied by the mechanical advantage of the lever
and is more than sufficient to hold the clapper closed
against normal supply pressure surges.
When a fire is detected, the energized solenoid valve s vent
the air from the Model LP Dry Valve Actuator (see Fig. 8),
which in turn vents the push rod chamber to atmosphere
through the chamber’s outlet. Since the pressure cannot be
replenished through the inlet restriction as rapidly as it is
vented, the pushrod chamber pressure falls instanta-
neously. When the pushrod chamber pressure approaches
approximately one-third of the supply pressure, the upward
force of the supply pressure acting beneath the clapper
overcomes the lever-applied force thereby opening the
clapper.