7.
Pressurizing Line Connection
The water supply for the push-rod chamber must be
provided by connection of its inlet pressurizing line to the
water supply piping. Pressurizing lines for multiple
Model DDX Deluge Valve push-rod chambers must
never be manifolded together, having only a single tap
on the water supply piping. Each Model DDX Deluge
Valve must have its own push-rod chamber pressurizing
line connection. This connection must be made on the
supply side of the main water supply control valve. This
can be accomplished by:
a.
Using a tapped connection directly below or next to
the main water supply control valve using a welded
outlet or the appropriate mechanical fittings. A
grooved-end outlet coupling is one way to achieve
this.
b.
Using a water supply control valve that has an avail-
able threaded (NPT) supply-side tap design to allow
for a direct water supply connection to the Model DDX
Deluge Valve’s push-rod chamber.
Caution:
Reliable’s Model DDX Deluge Valve is de-
signed with an inlet restriction built into the pushrod
chamber. It is important not to introduce additional re-
strictions into the direct water supply connection or the
discharge from the pushrod chamber by installing addi-
tional valves or improperly installing the copper lines
used in the trim of the valve.
System Design Considerations
The automatic sprinklers, air compressor, releasing de-
vices, electric releasing control equipment, fire detec-
tion devices, manual pull stations, and signaling devices
which are utilized with this Reliable Single Interlock
Preaction System must be Loss Prevention Certification
Board (LPCB) approved, as applicable.
The
deluge valve and all interconnecting piping must
be located in a readily visible and accessible location
and in an area that can be maintained at a minimum tem-
perature of 40°F (4°C).
Note:
Heat tracing is not permit-
ted.
The redundant solenoid valves are operated and su-
pervised by an electrical releasing/control panel. Details
on the electrical connections and the
Prescient Pre-Ac-
tion Sprinkler Extinguishing Fire Alarm Panel can be
found on Figure 5 of this bulletin.
System Air Pressure Requirements
When a Reliable Single Interlock Preaction System is
utilized, the sprinkler system piping requires a minimum
of 7 psi (0,5 bar) supervisory pneumatic pressure. The
Model A-2 Pressure Maintenance Device, along with an
additional air pressure regulator, are used to maintain
the system’s pneumatic pressure between 7 and 10 psi
(0,5 and 0,7 bar) where a dry nitrogen gas supply or a
clean, dependable, and continuous (24 hours per day, 7
days per week) compressed air source is available.
The sections of the preaction trim that contains the two
redundant normally-closed solenoid valves, and the up-
per portion of the Model LP Dry Valve Actuator, require
pneumatic pressure settings per Table A. When estab-
lishing the preaction system for service, refer to Table A of
this bulletin for the correct pneumatic pressure settings for
a corresponding water supply pressure.
Note:
During
the initial system set-up, a higher pneumatic pressure
may be required in order to properly seat the internal dia-
phragm of Model LP Dry Valve Actuator.
Refer to Reliable Bulletin 251 and/or Fig. 3 of this bulletin
for instructions on how to modify these pressure
settings.
System Electrical Requirements
All releasing, alarm and detection devices in this Reliable
Single Interlock Preaction System are supervised by the
Prescient Pre-Action Sprinkler Extinguishing Fire Alarm
Panel
. Connect these devices as shown in Fig. 5. The
power supply, the standby emergency power supply, bat-
tery charger, and the rectifier circuitry are all contained
within this panel. For additional and detailed wiring infor-
mation, refer to the manufacturer’s literature included with
the Prescient Releasing Control Panel.
Caution:
Repairs
or disassembly of the solenoid valves should only be
done by a trained technician. An improperly repaired or
partially assembled solenoid valve could result in failure of
the valve to operate.
Water Pressure
psi (bar)
Pneumatic Pressure to be Pumped
into Sprinkler System, psi (bar)
Maximum
Not Less Than
Not More Than
20
(1,4)
10 (0,7)
14 (0,9)
50
(3,4)
12 (0,8)
16 (1,1)
75
(5,2)
13 (0,9)
17 (1,2)
100
(6,9)
15 (1,0)
19 (1,3)
125
(8,6)
16 (1,1)
20 (1,4)
150
(10,3)
17 (1,2)
21 (1,4)
175
(12,1)
18 (1,2)
22 (1,5)
Table A
Summary of Contents for Single Interlock Preaction System
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