9.
pressure range of 5 to 50 psi (0,34 to 3,4 bar). The
pressure maintenance device shall have aworking
pressure rating of 175 psi (12,1 bar). Recom-
mended pneumatic supervisory pressure shall be
10 psi (0,70 bar). Pressure maintenance device
shall be Reliable Model A-2.
Double Interlock Preaction System shall be a Reliable
Double Interlock Type D Preaction System, Bulletin 737.
Pneumatic Supervisory Pressure Supply Options
Owner’s Air supply
Air supply shall be provided by an owner-supplied air
system.
Compressed Air Supply
Air supply shall be provided by an automatic
tank-mounted air compressor sized (appropriate hp) for
the capacity (volume) of the sprinkler system piping, and
be capable of restoring normal air pressure in the system
within 30 minutes. 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 pres-
sure regulator, equipped with high pressure inlet and low
pressure outlet gauges, and ¼” copper connection tub-
ing with galvanized ¾” x ¼” reducer bushing. Optional:
Low-pressure trim kit shall be included to monitor the reg-
ulated nitrogen supply pressure to provide a low-pressure
supervisory alarm. This kit shall include a low-pressure
switch with associated galvanized connection trim. As-
sembly 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] [FM Approved] indicating butterfly type
valve with a pre-wired supervisory tamper switch assem-
bly. The valve shall be rated for a working pressure of
[175 psi (12,1 bar)] [250 psi (17,2 bar)]. System control
valve shall be a [2” (50 mm)] Nibco KG-505-w-8 Ball
Valve, [2
1
2
” (65 mm)] [3” (80 mm)] Nibco GD-4765-8N
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 contain-
ing two initiating device circuits, and waterflow and super-
visory 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 actuate. Releas-
ing/control panel shall be equipped with a local tone
alarm to annunciate loss of AC power, system trouble, cir-
cuit trouble, and low auxiliary DC power supply. Panel
shall be [cULus Listed] [FMApproved] 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 con-
sist 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 re-
mote annunciation of alarm, trouble, and supervisory
panel signals. Main power supply to be a dedicated 120
VAC / 60Hz 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] [FM Approved] and of the
bellows activated type enclosed in a weatherproof, 4x,
NEMA 4-rated enclosure incorporating tamper-resistant
screws. There shall be two sets of SPDT (Form C) con-
tacts rated at 10.0 A @ 125/250 VAC and 2.5 A @ 6/12/24
VDC. 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 20 psi (1,3bar). Switch shall be
provided with a ½” NPT male pressure connection.
Waterflow alarm pressure switch shall be System Sensor
EPS10-2.
