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The Viking Corporation, 210 N Industrial Park Drive, Hastings MI 49058
Telephone: 269-945-9501 Technical Services: 877-384-5464 Fax: 269-818-1680 Email: techsvcs@vikingcorp.com
Figure 2 - Alarm Pressure Switch Wiring
(Alarm Pressure Switch should be set to 5 psi)
Figure 3 - Air Supervisory Switch Wiring
Special attention must be given to systems employing a bottled-gas supply. Because only a limited amount of gas is available, small
leaks which normally would go unnoticed in systems being supplied by mechanical compressors, can become critical to the system's
overall performance. If the system is to function at temperatures as low as -40 °F (-40 °C), and, if bottled nitrogen is the gas supply, the
system is particularly susceptible to leakage, and special care should be taken to ensure against leaks throughout the entire system.
C. Air Supply Installation
1. Install the required air supply as described in section 4.B. The size of the compressor and amount of air required should be
determined in accordance with Tables 1, 2 & 3. The air or nitrogen supply to the Preaction System must be clean, dry, and
oil free.
2. Automatic air supplies must be regulated, restricted, and from a continuous source. A Viking Air Maintenance Device should
be installed on each system equipped with a tank mounted compressor, plant air or nitrogen. For compressors with a capacity
3
less than 5.5 ft
/min at 10 psig (0.154 m
an air maintenance device with riser mounted compressors can lead to compressor "short cycling". Viking always recom-
mends that a tank mounted compressor with air maintenance device be used. This can become critical when accelerators
are installed on the system.
D. Pressure Switch Wiring;
Wire the Alarm Pressure Switch (PS10) and Air Supervisory Switch (PS40), and adjust pressure settings as shown in Figures 2 - 4.
E. Hydrostatic Test:
The Preaction System, including Sprinkler Piping and Sprinklers shall be hydrostatically tested at 200 psi (13.79 bar) and maintained
for 2 hours, in accordance with NFPA 13. Systems normally subjected to working system pressures in excess of 150 psi (10.34 bar)
shall be tested at a pressure of 50 psi (3.45 bar) in excess of system working pressure.
F. Placing the Valve in Service: (Refer to Figure 5)
When the Preaction System is ready to be placed in service, verify that the pneumatic release system is in a normal condition and
that the electric release system has been reset.
1. Verify that the water supply main control valve supplying the G-4000P Valve is closed.
2. Close the prime valve.
3. Open the main drain valve.
4. Open the flow test valve.
Form No. F_112008
18.10.25
TECHNICAL DATA
3
/min at 0.69 bar), NFPA 13 does not require an air maintenance device. The use of
P65
4" MODEL G-4000P
DOUBLE INTERLOCK PREACTION
WITH ELECTRIC/PNEUMATIC RELEASE
FIELD ADJUSTMENTS:
Alarm Pressure Switch: The operating point of the switch can be
adjusted to any point between 4 PSI (0.27 bar) and 8 PSI (0.55 bar)
by turning the adjustment knob(s) clockwise to raise the actuation
point or counter-clockwise to lower the actuation point.
Air Supervisory Switch: The operating point of the switches can
be adjusted to any point between 10 PSI (0.7 bar) and 60 PSI
(4.1 bar) by turning the adjustment knob(s) clockwise to raise the
actuation point or counter-clockwise to lower the actuation point.
The high and low switches are adjusted independently.
Figure 4 - Pressure Adjustment
Page 4 of 12
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