2.
C. Detection and notication of a re condition are provided by
re detectors, without the delay associated with water delivery
time in the event of a re. Note that with a wet pipe system, the
re alarm is delayed until after water has begun flowing from an
operated sprinkler.
In single interlock applications, one or more detectors sense the
presence of re, thereby causing the electrical releasing control
panel to activate notication appliances and energize the solenoid
releasing valve to the open position. The use of cross-zoned de-
tectors will require operation of two detectors on separate zones
before the solenoid valve can open (Note: Verify that the detection
method, including the use of cross-zoned detection, are permitted
by all applicable codes and standards, as well as the requirements
of all authorities having jurisdiction. Cross-zoned detection may not
be permitted in New York City or by Factory Mutual.) The solenoid
valve, when closed, preserves supply water pressure in the Model
DDX valve’s push-rod chamber. Actuating the solenoid valve re-
leases that water pressure which allows the Model DDX valve to
open.
To discharge water from sprinklers on a single interlock system
with cross-zoned detection, two separate electrical detection zone
must activate and a sprinkler must open. During the early stages
of a re, smoke or heat activates the rst detector, which causes
the control panel to produce a local alarm and an alarm at the re
alarm panel. Electrical relays inside the releasing control panel can
be used to shut down air moving equipment or activate security
doors and other electrical devices when the panel goes into this
rst condition. Subsequent activation of a second, nearby or adja-
cent detector, on a separate detection zone, will cause the panel to
energize the solenoid valve open and release water into the sprin-
kler piping. Water flowing into the sprinkler piping will simultaneously
produce water pressure that cause the transfer of contacts in the
alarm pressure switch mounted in the riser assembly, thereby acti-
vating a water flow alarm device. The flow of water into the sprinkler
piping effectively converts the dry system into a wet-pipe sprinkler
system. In the event that the re subsequently produces sufcient
heat to operate a sprinkler, water will flow from that sprinkler.
To flow water into a double interlock preaction system, two events
must take place: a re detection device must operate, and a pres-
sure switch must be operated by the loss of system pressure (sprin-
kler operation). These two signals, an electric signal from the detec-
tion system and an electrical signal from the pressure (pneumatic)
sensor, 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 is ac-
cidentally opened, the system pressure switch will operate and an
alarm will sound. The Model DDX Type D however, will not release
water since the detection system has not been activated.
When using the Reliable Model DDX PrePaK system in either sin-
gle or double interlock applications, the sprinkler system is pressur-
ized (supervised) with air or nitrogen and is monitored by a system
pressure switch.
A Model B Hydraulic Manual Emergency Releasing station is
standard equipment in the Model DDX PrePaK system. 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 system assembly. The cable tie
is designed to allow, in case of an emergency, forceful turning of the
valve handle to the ON position.
Approvals
1. Underwriters Laboratories, Inc. Listed and Certied for Cana-
da* (cULus) as an assembled unit in the “Special System Wa-
ter Control Valves Assembled Units” category, (VKYL).
2. Factory Mutual (FM) Approved, as PrePaK Single Interlock
and Double Interlock Preaction Systems.
* Electrical devices and control panel must be specied to
meet Canadian requirements. This option is available.
3. Approved for use in New York City based on UL Listing.
Note: Although PrePaK system units are UL Listed, custom
built units are sometimes supplied upon request. The components
within these special units maintain their individual Listings/Approv-
als, whereas the assembled units do not.
PrePaK system units are also available without the Potter PFC-
4410-RC Releasing/ Control Panel and Air Compressor. These
units will still retain their Listings/Approvals, however the installing
contractor should make sure that any remote controlled Releasing/
Control Panels used with these units are Listed/Approved and pro-
grammed to handle the required sequence of operation necessary
to operate the automatic sprinkler system. Any unauthorized modi-
cation or addition made on-site to a factory-built Listed/Approved
unit will void the Listing/Approval. Such modications or additions
may void the unit’s warranty as well. Consult Reliable’s Technical
Services Department before proceeding with any such modica-
tions or additions.
Technical Data
1. The Reliable Model DDX PrePaK systems are rated for a mini-
mum supply pressure of 20 psi (1.4 bar) and a maximum sup-
ply pressure of 250 psi (17.2 bar).
2. Friction loss, expressed in equivalent length of Schedule 40
pipe and based on Hazen-Williams Formula with C=120 and a
flowing velocity of 15 ft/s (4.6 m/s), is:
System Size Equivalent Length
2” (50mm) 4.4’ (1.3m)
2-1/2” (65mm) 6.0’ (1.8m)
3” (80mm) 12.6’ (3.8m)
4” (100 mm) 32.8 ft (17.7 m)
6” (150 mm) 54.7 ft (21.8 m)
8” (200mm) 79.3ft (24.2m)
These values account for the Model DDX valve, supply mani-
fold tee, butterfly control valve, and the short section of pipe
located directly above Model DDX valve.
3. Shipping Weight:
System Size Weight
2” (50mm)
565 lbs (256 kg)2-1/2” (65mm)
3” (80mm)
4” (100 mm) 690 lbs (313 kg)
6” (150 mm) 850 lbs (386 kg)
8" (200mm) 940lbs (426kg)
4. Please reference Figure 1 for dimensions.
