Technical data

Page 39
TECHNICAL DATA
The Viking Corporation, 210 N Industrial Park Drive, Hastings MI 49058
Telephone: [phone] Technical Services: 877-384-5464 Fax: [phone] Email: [e-mail]
February, 2010
PREACTION SPRINKLER
SYSTEM
In fire conditions, when the detection system operates, the VFR400 Control Panel activates the
system alarm and initiates the appropriate detection alarms. No water enters the system piping
at this time. When a sprinkler operates, system supervisory air is lost, and the low air pressure
switch is activated. Only after both indicating circuits have operated, the VFR400 Control Panel
energizes normally closed release solenoid valve open and normally open release solenoid valve
closed.
Pressure is released from the priming chamber faster than it is supplied through restricted orifice.
The deluge valve clapper opens to allow water flow into the system piping and to alarm devices.
Water entering the system piping increases pressure on the PORV, which vents off the water sup-
ply to the priming chamber. Water will flow from any open sprinklers or nozzles.
F. SUREFIRE
®
PREACTION SYSTEM WITH THE MODEL G SERIES VALVE (Figure 19)
Viking supervised Surefire
®
Preaction Systems utilize the Model G-2000P, G-3000P, or G-4000P
Valve. The system piping is pressurized with air or nitrogen for all Surefire
®
systems as part of the fail
safe release and to supervise the integrity of the piping under normal power conditions. This feature
serves to prevent undetected leaks in the system piping network and allows automatic fire protection
upon complete loss of power. If the system piping or a sprinkler is damaged, the supervisory pressure
is reduced and a “low air” supervisory alarm is activated.
Surefire
®
preaction systems require one 24 VDC normally closed electric solenoid valve and one
24 VDC normally open solenoid valve controlled by the Viking VFR-400 Release Control Panel with
a compatible detection system. In addition, a pneumatic actuator is required as part of the release
system.
In the set position, when air pressure is introduced into the sprinkler piping, the sensing end of the
pneumatic actuator is pressurized. This closes the pneumatic actuator. The closed pneumatic actua-
tor, and the normally closed solenoid valve prevent prime water from escaping the prime chamber of
the deluge valve. When prime water enters the prime chamber, the rolling diaphragm is pressurized,
causing it to expand downward onto the water seat.
1. Surefire
®
Single Interlock Preaction System
When the detection system operates, the normally closed solenoid valve is powered open. Prime
water is drained from the prime chamber, causing the deluge valve to open, filling the sprinkler
piping with water. Water from the intermediate chamber of the deluge valve pressurizes the sens-
ing end of the D-1 PORV causing the PORV to open. The open PORV prevents water pressure
from building in the deluge valve prime chamber.
2. Surefi re
®
Double Interlock Preaction System
When the detection system operates and a sprinkler head operates, the normally closed solenoid
valve is powered open. Prime water is drained from the prime chamber, causing the deluge valve
to open, filling the sprinkler piping with water. Water from the intermediate chamber of the deluge
valve pressurizes the sensing end of the D-1 PORV, causing the PORV to open. The open PORV
prevents water pressure from building in the deluge valve prime chamber.