Preaction Valve
Model A, 3 Inch (DN80)
With Double Interlock
Electric/Pneumatic Release Trim
GENERAL DESCRIPTION
The Star 3 inch (DN80) Model A Preaction Valve with
Double Interlock Electric/Pneumatic Release Trim is de-
signed for use in applications, such as refrigerated areas,
requiring the maximum degree of protection against inad-
vertent flooding of the sprinkler system piping. In order for
the Model A Preaction Valve to automatically actuate and
permit water to enter the sprinkler system piping, two in-
dependent events must occur — the electric fire detection
system must respond to a fire condition and one or more
automatic sprinklers must operate.
The Model A Preaction Valve features a double seat de-
sign eliminating the use of a separate air check valve in
the system riser. Also, the Model A Preaction Valve has
been designed to operate without prime water, conse-
quently eliminating yet another additional check valve in
the system riser for refrigerated area systems.
In the case of the electric/pneumatic release of the Model
A Preaction Valve, the releasing trim consisting of both a
Solenoid Valve (electrically operated releasing valve) and
a Dry Pilot Actuator (air operated releasing valve) in a se-
ries configuration is utilized. The double seat design of
the Model A Preaction Valve isolates the system air pres-
sure, which holds the Dry Pilot Actuator closed. The Sole-
noid Valve remains closed until it is electrically energized
by a releasing panel that is operated by either an electric
fire detection device or electric manual pull station.
As an option for water supplies of 35 psi (2.4 bar) or
more, the Model A Preaction Valve may be equipped with
414-570-5000 • 800-558-5236 • FAX 414-570-5010
6-00
2-4.1.10
STAR SPRINKLER INC.
www.starsprinkler.com
#3000 Valve, F x F
#3008 Trim
FIGURE 1
GENERAL ARRANGEMENT FOR ELECTRIC/PNEUMATIC DOUBLE INTERLOCK PREACTION SYSTEM
RELEASE TRIM
MODEL A PREACTION VALVE
WITH DOUBLE INTERLOCK
ELECTRIC/PNEUMATIC
WATER SUPPLY
OPEN)
SYSTEM MAIN
CONTROL VALVE
(SUPERVISED
MAINTENANCE DEVICE
(OR REFRIGERATED SPACE
AIR SUPPLY PER NFPA 13)
SUPPLY WATER
CIRCUIT
FIRE
DETECTION
INITIATING
OPEN)
SYSTEM
SHUT-OFF VALVE
(SUPERVISED
AUTOMATIC SPRINKLERS
2 FEET
(609.6 mm)
MINIMUM
SYSTEM TRIP
TEST FLOW VALVE
PRESSURE
SYSTEM AIR
PRESSURE
MODEL S460 AIR
AUDIBLE
ALARM
CIRCUIT
BACK-UP
PANEL
WITH 24 VDC
BATTERY
RELEASING
ELECTRIC DETECTION
WATERFLOW ALARM
INITIATING CIRCUIT
24 VDC SOLENOID VALVE
RELEASING CIRCUIT
-
SUPERVISORY ALARM
INITIATING CIRCUITS:
-
-
ELECTRIC
MANUAL PULL
INITIATING
SYSTEM SHUT-OFF VALVE
LOW AIR
SYSTEM MAIN CONTROL VALVE
CIRCUIT
120 VAC
OBSOLETE
