Specifications

System Operation
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 positions 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 resultant force
due to the supply pressure acting on the push rod is multi-
plied by the mechanical advantage of the lever and is more
than sufficient to hold the clapper closed against normal sup-
ply pressure surges.
To fully operate (deliver water) a Wet Pilot Line Single Inter-
lock Preaction System, two independent events must coexist
before water flow will occur. A wet pilot line sprinkler/detector
must fuse along with a fire sprinkler head. Operation of either
one of these heads will cause an alarm to annunciate, but
will not cause water discharge from the fire sprinkler system
piping.
When a fire is detected, the opened wet pilot line sprinkler/
detector vents the push rod chamber to atmosphere through
the chamber’s outlet. Since the pressure cannot be replen-
ished through the inlet restriction as rapidly as it is vented, the
push rod chamber pressure falls instantaneously. When the
push rod 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.
To fully operate an Electric Actuation Single Interlock Pre-
action System, 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 a fire is detected, the energized solenoid valve 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 cham-
ber pressure falls instantaneously. When the pushrod cham-
ber pressure approaches approximately one-third of the sup-
ply pressure, the upward force of the supply pressure acting
beneath the clapper over comes the lever-applied force
thereby opening the clapper.
To fully operate (deliver water) a Dry Pilot Line Single Inter-
lock Preaction System, two independent events must coexist
before water flow will occur. A dry pilot line sprinkler/detector
must fuse along with a fire sprinkler head. Operation of either
one of these heads will cause an alarm to annunciate, but
will not cause water discharge from the fire sprinkler system
piping.
When a fire is detected, the Model LP Dry Pilot Line Actua-
tor 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 push
rod chamber pressure falls instantaneously.
When the push rod chamber pressure approaches approx-
imately 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.
In all Reliable Single Interlock Preaction Systems, 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 pip-
ing. Water also flows through the Deluge Valve alarm outlet to
the alarm devices.
After system shutdown, resetting the Model DDX Deluge
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 simple, economical system testing,
which is one essential facet of a good maintenance program.
The external reset feature does not, however, eliminate an-
other important facet of good maintenance, namely, periodic
cleaning and inspection of the internal valve parts.
In the event that water builds up inside the valve due to
condensate from the air supply system or water left inside
from valve system testing, a drain is available for venting. Af-
ter 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 section
titled “Draining Excess/Condensate Water From System” in
this bulletin for the detailed procedure.
The Model B Manual Emergency Station (see Fig. 12) is
also included in all Reliable Single Interlock Preaction System
trim sets. It consists of an aluminum 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. 12, after the
system has been restored for operation. The nylon cable tie
is designed to allow, in case of an emergency, forceful turn-
ing of the valve handle to the ON position. As an alternative to
the Model B Hydraulic Manual Emergency Station, the Model
A Hydraulic Manual Emergency Pull Box (see Reliable Bul-
letin 506) is also available and can be provided as an option.
Whenever ambient temperature conditions are high, the
water temperature in the Model DDX Deluge Valve’s push-
rod chamber could possibly increase, thereby increasing the
pressure in the chamber to values exceeding the rated pres-
sure 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 in-
stalled into the pushrod chamber’s releasing line to limit the
pressure to 250 psi (17,2 bar).
Reliable Model DDX Deluge Valve with associated Single
Interlock Preaction Trims sizes 2” (50 mm), 2½” (65 mm), 76
mm, 3” (80 mm), 4” (100 mm), 165 mm, 6” (150 mm) and 8”
(200 mm) are rated for use at a minimum water supply pres-
sure of 20 psi (1,4 bar) and a maximum water supply pres-
sure of 250 psi (17,2 bar) for 2” (50mm), 2½” (65mm), 76mm,
3” (80mm) and 8” (200mm) valve sizes and 300 psi (20,7
bar) for 4” (100mm), 165mm and 6” (150mm) valve sizes.
Water supplied to the inlet of the valve and to the push rod
chamber must be maintained between 40˚F (4˚C) and 140˚F
(60˚C).
5.