12
Owner’s Air supply
Supervisory air supply shall be provided by an owner
supplied air system in conjunction with a [cULus Listed]
automatic pressure maintenance device, capable of
maintaining a constant system pressure regardless of
pressure fluctuations in the compressed air source.
Compressed Air Supply
Supervisory air supply shall be provided by an
automatic tank-mounted air compressor
sized
(appropriate hp (kW)) for the capacity (volume) of the double
interlock preaction system piping, and be capable of
restoring normal air pressure in the system within the time
limits specified by NFPA 13. Tank mounted compressor
shall be a motor mounted, oil-less, piston compressor,
including gauge, pressure switch, check valve, drain valve
and safety relief valve. Single-phase motor shall have
internal thermal protection.
Nitrogen
Nitrogen cylinders provided by an approved source shall
provide the nitrogen supply. The nitrogen cylinder pressure
shall be regulated and supervised through the use of nitrogen
regulating device and low-pressure trim kit. This device shall
consist of a brass, single stage pressure regulator, equipped
with high pressure inlet and low pressure outlet gauges, and
1
/
4
" copper connection tubing with galvanized
3
/
4
" x
1
/
4
"
reducer bushing. Optional: Low-pressure trim kit shall be
included to monitor the regulated nitrogen supply pressure
to provide a low-pressure supervisory alarm. This kit shall
include a low-pressure switch with associated galvanized
connection trim. Assembly shall be a Reliable Nitrogen
Regulating Device. This device is to be used in conjunction
with the Reliable Model A-2 Pressure Maintenance Device.
Optional System Accessories
System Control Valve
Preaction system control valve shall be a slow close,
[cULus Listed] indicating butterfly type valve with a pre-
wired supervisory tamper switch assembly. The valve shall
be rated for a working pressure of [300 psi (20.6 bar)].
System control valve shall be for a [2" (50 mm)] Gruvlok
AN7722-3A Butterfly Valve or [2-
1
/
2
" (65 mm)] [3" (80 mm)]
[4" (100 mm)] [6" (150 mm] [8" (200 mm] – Nibco GD-4865-
8N Butterfly Valve.
Detection System
To initiate actuation of the preaction system’s deluge valve,
a supplemental electric detection system shall be provided
[Insert applicable product specification].
Releasing/Control Panel
A releasing/control panel shall be used to operate the
preaction system. The releasing/control panel shall be a
conventional, microprocessor-controlled panel containing
two initiating device circuits, and waterflow and supervisory
inputs. Output circuits shall include alarm, waterflow,
supervisory, and releasing circuits. Mode of operation shall
be set for cross zoned operation, requiring both a detection
device input and a low air pressure switch input (sprinkler
operation) to energize the solenoid valve, causing the deluge
valve to operate. Releasing/control panel shall be equipped
with a local tone alarm to annunciate loss of AC power,
system trouble, circuit trouble, and low auxiliary DC power
supply. Panel shall be [cULus Listed] [FM Approved] and
be capable of providing power for compatible detectors
and auxiliary devices used. Audible alarms shall be able to
be silenced at releasing panel. Auxiliary DC power supply
shall consist of (2) 12-volt lead acid batteries of the same
ampere-hour rating, providing [60 hours – cULus Listed] [90
hours – FM Approved]. Dry contacts shall be provided for
remote annunciation of alarm, trouble, and supervisory panel
signals. Main power supply to be a dedicated a 120 V ac /
60 Hz circuit.
Waterflow Alarm Pressure Switch
Alarm pressure switch shall be provided to indicate water
flow and provide a water flow alarm. Pressure switch shall be
[cULus Listed] and of the bellows activated type enclosed in
a weatherproof, NEMA 4 /4X rated enclosure incorporating
tamper-resistant screws. There shall be two sets of SPDT
(Form C) contacts rated at 10.0 A @ 125 /250 V ac and 2.5 A
@ 6 / 12 / 24 V dc. The pressure switch shall have a maximum
service pressure rating of 250 psi (17.2 bar) and shall be
factory adjusted to operate at a pressure of 4 to 8 psi (0.27
to 0.55 bar) with adjustment up to 15 psi (1.03 bar). Switch
shall be provided with a
1
/
2
" NPT male pressure connection.
Waterflow alarm pressure switch shall be Potter PS10-2.
Technical Data
Reliable Double Interlock Type D Preaction Systems, with
associated trim, size 2" (50 mm), 2-
1
/
2
" (65 mm), 76 mm, 3"
(80 mm), 4" (100 mm), 165 mm, 6" (150 mm), 8" (200 mm)
are rated for use at minimum water supply pressure of 20 psi
(1.4 bar) and maximum supply pressure of 250 psi (17.2 bar)
for 2" (50 mm),
21
/
2
" (65 mm), 3" (80 mm), 76 mm and 8"
(200 mm) valve sizes and 300 psi (20.7 bar) for 4" (100 mm),
6" (150 mm) and 165 mm valve sizes. Water supplied to
the inlet of the valve and to the pushrod chamber must be
maintained between 40 °F (4 °C) and 140 °F (60 °C).
The following list of technical bulletins pertains to valves
and devices that may be used in this preaction system:
Deluge Valve
Reliable 518 / 519
Hydraulic Emergency
Station (Model A)
Reliable 506
Solenoid Valve
Reliable 718
Mechanical Sprinkler Alarm
Reliable 612 / 613
Pressure Maintenance Device
Reliable 254
Nitrogen Regulating Device
Reliable 254
Air Compressor
Gast F-30
Releasing/Control Panel
Potter #5403550
Low Air Pressure
Supervisory Switch
Potter 5400928
Waterflow Pressure Alarm Switch
Potter 5400928
Model DDX Deluge Valve Description
1. Rated working pressure:
Valve & System – 250 psi (17.2 bar) for 2" (50 mm),
2-
1
/
2
" (65 mm), 3" (80 mm), 76 mm and 8" (200 mm)
valve sizes and 300 psi (20.7 bar) for 4" (100 mm), 6"
(150 mm) and 165 mm valve sizes.
