Reliable N2-Blast DDX Maintenance manual

Reliable Automatic Sprinkler Co., Inc., 103 Fairview Park Drive, Elmsford, New York 10523
Model DDX N2-Blast®PrePaK™
Type F Preaction System
2” (50mm), 2-1/2” (65mm),
3” (80mm), 4”(100mm)
Bulletin 736 August 2020
Bulletin 736 August 2020
Instructions for
Installation, Operation,
Care and Maintenance
Double Interlock
Electric/Pneumatic Release
General Description
The Reliable Type F Model DDX PrePaK system with in-
tegrated nitrogen generation is a completely self-contained,
supervised preaction system that can be readily installed
within a floor space of less than 7 ft2(0.65 m2) (not including
door swing). Refer to Fig. 1 for cabinet dimensions. Instal-
lation of the PrePaK system (not including exterior devices,
i.e., detectors and alarm bells), requires just three piping
connections. These connections are the water supply, the
sprinkler system and the drain. Reference locations of these
piping connections are shown in Fig. 1. Independent electri-
cal supplies are required for the optional system air com-
pressor (115 or 220 VAC), the optional Potter Model 4410
Releasing Control Panel (115/220 VAC), and the nitrogen
generator (115 VAC).
Full assembly drawings for the units are available on the
Reliable Automatic Sprinkler Company website (www.reli-
ablesprinkler.com)
The Reliable Model DDX N2-Blast®PrePaK system incor-
porates a South-Tek Systems FPS-900 pressure swing ad-
sorption N2-Blast®nitrogen generator, complete with inde-
pendent air compressor, nitrogen storage tank, and control
system. The nitrogen generator is completely wired, tested,
and integrated with the Model DDX PrePaK system, and
supplies 98% pure nitrogen to the piping network to limit
electrochemical, galvanic, and micro-biologically influenced
corrosion (MIC). Operation and maintenance information
can be found in this bulletin as well as at the South-Tek Sys-
tems website (www.southteksystems.com).
The Reliable Type F PrePaK system utilizes an optional Pot-
ter Model PFC-4410-RC Releasing/Control Panel. This fully
programmable, microprocessor-based releasing panel is
Underwriters Laboratories, Inc. Listed and is in compliance
with NFPA 13 and NFPA 72. Because the PFC-4410-RC is
totally zone and output programmable, the Reliable Type F
PrePaK system can be utilized in many different preaction
applications without having to rewire any of the factory in-
stalled devices. Once the previously described connections
are completed, the 24 VDC detectors, output devices, and
relay contacts may be connected to achieve the desired
system implementation.
8 psi - 24 psi (0.6 bar - 1.7 bar)
System Air/Nitrogen Pressure
Note: N2-Blast®and Blast-off®are registered trademarks of
South-Tek Systems, LLC.

2.
The Type F PrePaK system is designed specifically for
double interlock applications. Reliable double interlock pre-
action systems are designed for water sensitive areas that
require protection from inadvertent water flow into the sprin-
kler system piping.
The major benefits of a double interlock preaction System,
when compared with a wet pipe system, are as follows:
A. A fire alarm sounds prior to the flow of water from
a sprinkler, which may enable extinguishment of
the fire by handheld means before the operation
of any sprinkler occurs.
B. An annunciator signals whenever the integrity of
piping or sprinklers is accidentally or intentionally
disturbed; however, no water flow occurs at that
time.
C. Detection and notification of a fire condition are
provided by fire detectors, without the delay as-
sociated with water delivery time in the event of
a fire. Note that with a wet pipe system, the fire
alarm is delayed until after water has begun flow-
ing from and operated sprinkler.
To flow water into the system piping of a Type F double
interlock preaction system, two events must take place:
1) A fire detection device must detect heat and/or
smoke thereby causing the releasing/control panel
to energize the normally-closed solenoid valve.
2) The sprinkler system piping must discharge enough
supervisory air for the Model LP Dry Pilot Actuator
to operate. This is generally the result of a sprinkler
operating due to fire.
In the event that the system piping is ruptured, or a sprin-
kler head is accidentally opened, the Model LP Dry Pilot
Actuator will open and a low system air pressure alarm will
sound. The Model DDX Deluge Valve, however, will not be
released to flow water since the solenoid valve still remains
closed. Conversely, in the event of a false detection signal,
the releasing/control panel will activate an alarm, but the
Model DDX Deluge Valve will not flow water due to the fact
that the Model LP Dry Pilot Actuator remains closed.
When using the Reliable Type F PrePaK system in double
interlock applications the sprinkler system is pressurized (su-
pervised) with air provided by the optional factory-installed
air compressor (or on-site Nitrogen supply) and is monitored
by a system pressure switch. If Nitrogen is used as the su-
pervisory gas, an optional Nitrogen Kit is available. This kit
contains a regulator and an additional pressure switch that
is used to monitor any low pressure conditions that may
arise due to having a limited Nitrogen supply. The optional
factory-installed air compressor can be utilized for make-up
air until the Nitrogen supply can be replenished.
Note: Compressed air is not to be considered as dry air
and may create ice plugs in the sprinkler system piping.
A Model B Hydraulic Manual Emergency Releasing station
is standard equipment in the Type F PrePaK system. It con-
sists 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 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
• The Model DDX N2-Blast PrePaK Type F preaction sys-
tem is FM Approved as a factory-assembled Preaction
System to Approval Standard 1011/1012/1013, Deluge
and Preaction Sprinkler Systems.
• The Model DDX deluge valve and Type F preaction trim
are FM Approved and cULus Listed.
• The South-Tek N2-Blast® Model FPS-900-RS nitrogen
generator is FM Approved to Approval Standard 1035,
Nitrogen Generators for Corrosion Mitigation.
Technical Data
1. The Reliable Model DDX Type F PrePaK system is
rated for a minimum water supply pressure of 20 psi
(1.4 bar). When fitted with the optional 300 psi (20.7
bar) solenoid, the 2”, 2-1/2”, 3”, and 8” sizes are
rated for a maximum pressure of 250 psi (17.2 bar),
and the 4” and 6” sizes are rated for a maximum
pressure of 300 psi (20.7 bar). Water temperature
must be maintained between 40°F and 140°F (4°C
and 60°C).
2. Friction loss, expressed in equivalent length of
Schedule 40 pipe and based on Hazen-Williams
Formula is:
System Size: Equivalent Length
2” (50mm) 19.4 ft (1.3 m)
2½” (65mm) 24.5 ft (1.8 m)
3” (80mm) 28.9 ft (3.8 m)
4” (100 mm) 32.8 ft (17.7 m)
These values account for the Model DDX Deluge Valve,
supply manifold tee, butterfly control valve, and small
pipe/manifold located directly above Model DDX Deluge
Valve.
3. Shipping Weight:
System Size Weight
2” (50mm)
950 lbs (431 kg)2-1/2” (65mm)
3” (80mm)
4” (100 mm) 1075 lbs (488 kg)
4. Please reference Figure 1 for dimensions.
The following is a list of Technical Data Bulletins which de-
scribe the valves and devices which are used in the system:
Device Reliable Bulletin #
(unless otherwise noted)
Model DDX Deluge Valve Reliable Bulletin 519
Type F Double Interlock Preaction Trim Reliable Bulletin 751
Low Air Pressure Switch Potter, 5401564
Alarm Pressure switch Potter, 5400928
Releasing Control Panel Potter Manual #5403550

3.
Fig. 1

4.
Hydrostatically testing the valve and trim to pressures higher
than their rating is limited to the hydrostatic test as referenced
by NFPA13. It does not address the occurrence(s) of a “wa-
ter hammer” effect, which can indeed damage the valve. A
“water hammer” in the water supply piping of the valve can
create pressures in excess of the rated pressure and should
be avoided by all necessary means. This condition may be
created from improper fire pump settings, underground con-
struction work, or an improper venting of trapped air in the wa-
ter supply piping.
System Air / Nitrogen Pressure Requirements
The Model DDX Type F PrePaK system includes gauges in-
dicating the pneumatic and water pressures of Model LP Dry
Pilot Actuator. Table A specifies the air or nitrogen pressure
level to be applied to the Actuator. The factory installed Pres-
sure Maintenance Device in the unit automatically provides
adequate makeup air or nitrogen flow to maintain supervisory
pressure with normal leakage for the system piping, while re-
stricting the flow of makeup air or nitrogen to allow for system
operation. Please note that when the optional Model B1 Ac-
celerator is to be utilized to expedite water-delivery time, the
pneumatic pressure must be not less than 15 psi (1.0 bar).
Table A
The following table provides a quick reference to the vari-
ous programs (found in this bulletin and the Potter Manual
#5403550) that may be utilized with a Type F PrePaK sys-
tem:
Desired Application Program
Single Interlock,
Single Zone
Potter Program #6
(Factory Setting)
Single Interlock,
Cross-Zoned Potter Program #7
Note: The Model DDX Type F PrePaK Double Interlock Preaction
system utilizes a solenoid controlled by single interlock program-
ming in conjunction with a pneumatic (mechanical) actuator.
Installation Requirements
The automatic sprinklers, releasing devices, fire
detection devices, manual pull stations, and signaling
devices which are utilized with the Reliable Model DDX
Type F PrePaK system must be UL and/or ULC Listed or
FM Approved, as applicable.
The steel enclosure and all the interconnecting piping
must be located indoors in a readily visible and acces-
sible location and in an area that can be maintained at a
minimum temperature of 40°F (4°C). Note: Heat tracing
is not permitted. The solenoid valve is operated and
supervised by the Potter Model PFC-4410-RC Releas-
ing Control Panel. Details on the electrical connections
of this system to the Potter Panel can be found in the
Potter Manual #5403550, Installation, Operation and
Instruction of PFC-4410-RC Releasing Control Panel
(this manual is included with other pertinent manuals
and shipped inside the enclosure). This panel is fully
zone and output programmable and may be adapted to
several applications. Hydrostatic Testing of DDX Valves
and DDX Systems.
Hydrostatic Testing of DDX Valves and
DDX Systems
As required by NFPA 13, fire sprinkler systems with work-
ing pressures up to and including 150 psi are to be hydro-
statically tested at a water pressure of 200 psi. Fire sprinkler
systems with working pressures above 150 psi are required to
be hydrostatically tested at 50 psi above the system working
pressure. In addition to the hydrostatic tests described above,
dry pipe and double interlock preaction systems require an
additional low pressure air test.
In some cases, hydrostatic testing (in accordance with the
NFPA 13 requirements noted above) will result in pressures
that exceed the working pressure of the valve and trim kit for
the two-hour test period. The valve and applicable trim kit have
been tested, approved and listed under these conditions and
as such, hydrostatic testing in accordance with NFPA 13 is ac-
ceptable. In addition, the clapper can remain in the closed po-
sition and the trim kit need not be isolated, as each has been
designed to withstand hydrostatic testing as required by NFPA
13.
Water Pressure psi (bar) System Air or Nitrogen Pressure
psi (bar)
Maximum Not Less Than
20 (1.4) 8 (0.6)
30 (2.1) 10 (0.7)
50 (3.4) 12 (.8)
75 (5.2) 13 (.9)
100 (6.9) 15 (1.)
125 (8.6) 16 (1.1)
150 (10.3) 17 (1.2)
175 (12.1) 18 (1.2)
200 (13.8) 19 (1.3)
225 (15.5) 21 (1.4)
250 (17.2) 22 (1.5)
275 (19.0) 23 (1.6)
300 (20.7) 24 (1.7)
Notes:
1. Supervisory air or nitrogen pressure should not exceed 30 psi (2.1
bar). Excess pressure may result in damage to the actuator.
2. Fastest valve operation is achieved with supervisory air or nitrogen
pressure indicated; however, pressure must never be less than the
minimum specified in the table above.
3. Air maintenance devices that maintain a constant pressure are
recommended; however, if a tank-less compressor is used, the
“compressor on” setting of the pressure switch must never be lower
than the minimum pressure in the table above.

5.
When the air compressor in the Model DDX Type F PrePaK
system is used to initially fill the sprinkler system with air, the
steel enclosure door should remain open to provide maxi-
mum intake air flow to the air compressor. The air compressor
is connected to a storage tank. This tank functions as a res-
ervoir, providing make-up air to compensate for small, inter-
mittent leaks in the sprinkler system. It should be noted that
significant leaks may overburden this storage tank, thereby
causing the air compressor to continuously cycle on and off.
The factory-installed system air pressure switch may need
on-site adjustment to correspond with the air pressure val-
ues found in Table A. Adjustment, if required, should be
made according to Potter Bulletin 5401564 included with
the switch.
System Electrical Requirements
All releasing, alarm, and detection devices in the Reli-
able Model DDX Type F PrePaK system are supervised by
a Potter Model PFC-4410-RC Releasing Control Panel. All
of the terminals are translated to a water-tight terminal box
mounted on the interior of the enclosure. All field wiring is
connected to this terminal box. Note: The EOL (End of Line)
resistors have also been relocated.
The Reliable Model DDX PrePaK system is delivered
with six factory-installed electrical devices. They consist of
the following:
1. A system air pressure switch, which is used to monitor
sprinkler piping.
2. An alarm pressure switch, which indicates an actuation
of the deluge valve.
3. A normally-closed, releasing solenoid valve, which is
used to actuate the deluge valve.
4. A 1/2 HP (2”, 2-1/2”, & 3” valve) or 1 HP (4” valve) air
compressor with tank.
5. A supervised butterfly (main control) valve (Note: A sys-
tem side butterfly valve is available as an option).
6. A release control disable switch (RCDS) which is used
to disable the solenoid valve for test purposes.
The factory electrical connections of these devices,
along with information on the connection of detection devic-
es (initiating zones 1 and 2), signaling devices, and super-
visory outputs to the Potter PFC4410-RC Releasing Control
Panel are included in this bulletin. The power supply, stand-
by emergency power supply, battery charger and rectifier
circuitry are all contained within the PFC4410 panel. Bat-
teries that provide 90 hours of standby power are provided
with the panel. For additional information and detailed wiring
diagrams, please refer to Potter Manual #5403550 (Instal-
lation, Operation and Instruction of PFC4410-RC Releasing
Control Panel).
Note: In order for the solenoid valve to maintain a warranty it
must remain sealed as it came from the factory. If there are
concerns about the valve’s internal components, immediate re-
placement is recommended.
System Operation (Double Interlock)
To fully activate (discharge water from) the Reliable Model
DDX Type F PrePaK system, a fire detection device must ac-
tivate and pneumatic pressure must be lost from the sprin-
kler system piping (normally from the activation of one or
more fire sprinklers).
When the system is properly set for service, the water sup-
ply pressure simultaneously acts on both the underside of
the deluge valve’s clapper and on the valve’s push rod by
means of the pressurized push rod chamber. The resultant
pressure force acting on the push rod, in unison with the me-
chanical advantage of the deluge valve lever, is more than
sufficient to hold the valve clapper in the closed position
against the water supply pressure.
Energizing the releasing solenoid valve is only one of the
events required towards opening the deluge valve. Air pres-
sure in the sprinkler system must also be reduced to a level
low enough to activate the Model LP Dry Pilot Actuator. Both
of these events allows the deluge valve’s push-rod chamber
to be vented to drain through its outlet. Since the push-rod
chamber pressure cannot be replenished through the inlet
restriction as rapidly as it is vented, the pressure falls rapidly.
When the push-rod chamber pressure drops below one-
third of the water supply pressure, the force acting beneath
the valve clapper becomes greater than the push-rod force
acting on the lever which causes the clapper to open. Refer
to Reliable Technical Bulletin 751 for further details.
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 and also through the alarm outlet to acti-
vate water flow alarm devices. Note that the solenoid valve
will be maintained open by the Potter Model PFC-4410-RC
Releasing/Control Panel latching feature until it is reset for
operation.
After system shutdown and draining, the Model DDX Del-
uge Valve clapper is easily reset without special tools us-
ing the external reset feature. Restore detection devices by
resetting or replacing any operated device. Once detection
devices are restored the system can be reset (see Resetting
Model DDX Type F Double Interlock Preaction System).
Resetting Model DDX Type F Double Interlock
Preaction System
1. Close the valve controlling water supply to the Del-
uge Valve and close the air or nitrogen supply to the
sprinkler system.
2. Close the pushrod chamber supply valve.
3. Open main drain valve and drain system.
4. Open all drain valves and vents at low points through-
out the system, closing them when flow of water has
stopped. Open the Model B Manual Emergency Station
to relieve pressure in the pushrod chamber of the Deluge
Valve.
5. With the alarm line valve open, push in the plunger of
ball drip valve, forcing the ball from its seat, and drain the
alarm line.