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Preaction 328d
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 (0.34 bar)
single Interlock
Figure 3 - Air supervisory switch wiring
NoTE: �iking recommends tank-mounted air com�ressors �or Double Interlock Electric/Pneu-Lectric Release Preaction Systems.
2. Nitrogen Cylinder Gas Su��ly (See Figure 1)
Nitrogen may be used in �lace o� air com�ressors. Nitrogen is su��lied in �ressurized cylinders in various sizes and �ressures.
Some o� the most common are 122 Cu. Ft. at 1,900 PSI (3,455 L at 131 bar), 225 Cu. Ft. at 2,100 PSI (6,372 L at 145 bar), and
280 Cu. Ft. at 2,300 PSI (7,930 L at 159 bar).
When nitrogen cylinders are used as a �rimary air su��ly, s�are cylinders should be �urnished and located at the valve location.
To determine the a��roximate amount o� nitrogen to be �urnished, the �ollowing �ormula may be used:
English Units
where:
�s x P
�c = �olume o� Cylinder (�t
�c =
100
P = Required Nitrogen Pressure (PSI)
� = �olume o� System (gal)
S�ecial attention must be given to systems em�loying a bottled-gas su��ly. Because only a limited amount o� gas is available,
small leaks, which normally would go unnoticed in systems being su��lied by mechanical com�ressors, can become critical to
the system's overall �er�ormance. I� the system is to �unction at tem�eratures as low as -40 °F (-40 °C), and, i� bottled nitrogen
is the gas su��ly, the system is �articularly susce�tible to leakage, and s�ecial care should be taken to ensure against leaks
throughout the entire system.
C. Air supply Installation:
1. Install the required air su��ly as described in section 4.B. The size o� the com�ressor and amount o� air required should be
determined in accordance with Tables 1 - 3. The air or nitrogen su��ly to the �reaction system must be clean, dry, and oil �ree.
2. Automatic air su��lies must be regulated, restricted, and �rom a continuous source. A �iking Air Maintenance Device should
be installed on each system equi��ed with a tank-mounted com�ressor, �lant air, or nitrogen. For com�ressors with a ca�acity
less than 5.5 �t
3
/min at 10 PSI (0.154 m
an air maintenance device should not be used with riser mounted com�ressors as this can lead to com�ressor "short cycling".
�iking recommends that a tank-mounted com�ressor 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 Su�ervisory Switch (PS40), and adjust �ressure settings as shown in Figures 2 - 4.
TECHNICAL DATA
Double Interlock
3
)
(0.154 m
3
/min at 0.69 bar), NFPA 13 does not require an air maintenance device. In addition,
2" MoDEL G-2000P PrEACTIoN
wITH ELECTrIC rELEAsE
FIELD ADJUsTMENTs:
Alarm Pressure switch: The o�erating �oint o� the switch can be
adjusted to any �oint between 4 PSI (0.27 bar) and 8 PSI (0.55 bar)
by turning the adjustment knob(s) clockwise to raise the actuation
�oint or counter-clockwise to lower the actuation �oint.
Air supervisory switch: The o�erating �oint o� the switches can
be adjusted to any �oint between 10 PSI (0.7 bar) and 60 PSI
(4.1 bar) by turning the adjustment knob(s) clockwise to raise the
actuation �oint or counter-clockwise to lower the actuation �oint.
The high and low switches are adjusted inde�endently.
Figure 4 - Pressure Adjustment
Metric Units
where:
�s x P
�c = �olume o� Cylinder (L)
�c =
108
P = Required Nitrogen Pressure (bar)
� = �olume o� System (L)
NFPA 13 does not require an air maintenance device. In addition,
January 6, 2012
This can become critical when
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