Technical data

2.
General Description
The Reliable Model DDX 2” (50 mm), 2½” (65 mm) and 3” (80
mm) PrePaKs are completely self-contained, supervised pre-
action systems that can be readily installed within a floor space
of 4.5 ft
2
(0.42 m
2
) (not including door swing). Installation of the
PrePaK (not including exterior devices, i.e., detectors and alarm
bells), requires just three piping connections: a 2” (50 mm), 2½”
(65 mm) or 3” (80 mm) supply line, a 2” (50 mm), 2½” (65 mm) or
3” (80 mm) system line, and a 1” (32 mm) drain line. Reference lo-
cations of these piping connections are shown in Fig.1. Also, two
120 / 220 VAC electrical supply connections are required. Note:
The Model DDX PrePak is available with its air compressor and
Potter Model PFC-4410-RC Releasing/Control Panel wired for a
120 VAC / 60Hz or for a 220 VAC / 50 Hz power supply.
The Reliable Model DDX PrePaK contains the following compo-
nents within its 24” (0.61 m) W x 27” (0.69 m) D x 68” (1.73 m) H
12-gauge steel enclosure:
One Reliable Model DDX 2” (50 mm), 2½” (65 mm) or
3” (80 mm) Deluge Value with Type D Double Interlock
Preaction Trim set (See Reliable Bulletin 737).
One Gast Model 1HAB-11T-M100X Hp Air Compres-
sor (2” & 2½” sizes) or one Gast Model 3HEB-13T-
M345 HP Air Compressor (3” Size.)
One 2 gallon (9.1 liter) air tank.
One Potter Model PFC-4410-RC Releasing/Control
Panel (See Potter Manual #5403550).
One Pressure Maintenance Device for system air su-
pervision (contains regulator, check valve, strainer, and
rapid-fill option).
All required fittings, gauges, electrical connectors, and
electrical devices to utilize the system in single inter-
lock, single interlock cross-zoned, double interlock,
and double interlock cross-zoned applications.
The Reliable Model DDX PrePaK utilizes the Potter Model PFC-
4410-RC Releasing Control Panel. This fully programmable, mi-
croprocessor-based releasing panel is Underwriters Laborato-
ries, Inc. Listed and is in compliance with NFPA 13 and NFPA 72.
Because the PFC-4410-RC is totally zone and output program-
mable, the Reliable Model DDX PrePaK can be utilized in many
different preaction applications without having to rewire any of the
factory installed devices. Once the previously described connec-
tions are completed, the 24 VDC detectors, output devices, and
relay contacts may be connected to achieve the desired system
implementation.
The Model DDX PrePaK can be used in both single and double
interlock applications. Reliable Single and Double Interlock Pre-
action Systems are designed for water sensitive areas that require
protection from inadvertent water flow into the sprinkler system
piping.
The major benefits of a single/double interlock preaction Sys-
tem, when compared with a wet pipe system, are as follows:
A fire alarm sounds prior to the flow of water from a sprin-
kler, which may enable extinguishing the fire by handheld
means before the operation of any sprinkler head occurs.
An annunciator signals whenever the integrity of piping or
sprinklers is accidentally or intentionally disturbed; however,
no water flow or water damage will result at that time.
Speedy detection and an early fire alarm are provided by
fire detectors, without the delay associated with water de-
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A.
B.
C.
livery time in the event of a fire. Note that with a wet pipe
system, the fire alarm is delayed until after water has begun
flowing from and operated sprinkler head.
In single interlock applications, one electrical detector senses
the presence of fire, thereby causing the electrical releasing con-
trol panel to activate fire alarm devices and energize the solenoid
releasing valve in the open position. Note that arranging detec-
tors in a cross-zoned pattern will require operation of two detec-
tors before the solenoid valve can open (Note: Cross-zoned de-
tection systems are not permitted in New York City and are not
Factory Mutual Approved). The solenoid valve, when closed, is
preserving supply water pressure in the deluge valve’s push-rod
chamber. Actuating the solenoid valve releases that water pres-
sure which allows the valve to open.
To fully operate a single interlock system with cross-zoned
detection, two separate electrical detection systems must acti-
vate and a sprinkler must open. During the early stages of a fire,
smoke or heat activates the first detector, which causes the con-
trol panel to produce a local alarm and an alarm at the main fire
alarm panel. Electrical relays inside the releasing control panel
can be used to shut down air moving equipment or activate se-
curity doors and other electrical devices when the panel goes into
this first condition. Subsequent activation of a second, nearby or
adjacent detector, on a separate detection system, will cause the
panel to energize the solenoid valve open and release water into
the sprinkler piping. Water flowing into the sprinkler piping will si-
multaneously produce water pressure that causes the transfer of
contacts in the alarm pressure switch mounted in the riser assem-
bly, thereby activating a water flow alarm device. The flow of water
into the sprinkler piping effectively converts the dry system into
a wet pipe system. In the event the fire subsequently produces
sufficient heat to operate a sprinkler head, water will flow from that
sprinkler, controlling the fire.
To flow water into a double interlock preaction system, two
events must take place. A fire detection device must operate,
and a pressure switch must be operated by the loss of system
pressure (sprinkler operation). These two signals, both an elec-
tric signal and a pneumatic signal, must coexist at the releasing
control panel, which only then will energize the solenoid releasing
valve, causing water flow into the sprinkler system and out of the
open sprinkler(s).
In the event that the system piping is ruptured or a sprinkler
head is accidentally opened, the system pressure switch will op-
erate and an alarm will sound. The riser assembly, however, will
not release water since the solenoid valve remains closed due to
only one input into the releasing control panel.
When using the Reliable Model DDX PrePaK, in either single or
double interlock applications, the sprinkler system is pressurized
(supervised) with air provided by the air compressor and is moni-
tored by a system pressure switch.
A Model B Hydraulic Manual Emergency Releasing station
is standard equipment in the Model DDX PrePaK. It consists of
an aluminum nameplate mechanically attached to a ball valve.
The valve handle in its OFF position is guarded against acciden-
tal turning to the ON position (and system discharge) by a nylon
cable tie provided with the PrePaK assembly. The cable tie is de-
signed to allow, in case of an emergency, forceful turning of the
valve handle to the ON position.