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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
Table 1 - Pipe Capacity for Sizing Air Compressors
Pipe Diameter
Schedule 40 (1" to 6")
US
International
1"
DN25
1-1/4"
DN32
1-1/2"
DN40
2"
DN50
2-1/2"
DN65
3"
DN80
3-1/2"
DN90
4"
DN100
5"
DN125
6"
DN150
8"
DN200
For Metric Units 1 Ft. = 0.3048 M, 1 Gal. = 3.785L
a valve house (enclosure) with adequate heat around the
G-2000P Valve and trim. Freezing temperatures will damage
the G-2000P Valve. When corrosive atmospheres and/or
contaminated water supplies are present, it is the owner's
responsibility to verify compatibility with the G-2000P Valve
and associated equipment.
4. The Viking Model E-1 Accelerator should be installed at
the location indicated in Figure 1 when required.
B. Air Supply Design
1. Air Compressor Size
Viking recommends tank-mounted air compressors for Double Interlock Electric/Pneumatic Release Preaction Systems. The pneumatic
actuator requires at least 30 PSI (2.1 bar) of air pressure be established within the piping network for systems with water pressure up
to 175 PSI (12.1 bar) and 50 PSI (3.45 bar) of air pressure for systems with water pressures up to 250 PSI (17.2 bar).
NFPA 13 requires the air supply to be capable of filling the entire sprinkler system to its required air pressure within 30 minutes. A com-
mon method of sizing an air compressor is to use the following formula:
V x P
Compressor
Size (cfm) =
7.48 x 14.7 x T
Therefore, the compressor shall be capable of providing 7 cfm.
2. Nitrogen Cylinder Gas Supply (See Figure 1)
Nitrogen may be used in place of air compressors. Nitrogen is supplied in pressurized cylinders in various sizes and pressures. Some
of 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 primary air supply, spare cylinders should be furnished and located at the valve location.
To determine the approximate amount of nitrogen to be furnished, the following formula may be used:
English Units
Where:
Vs x P
Vc = Volume of Cylinder (ft
Vc =
100
P = Required Nitrogen Pressure (PSIg)
V = Volume of System (gal)
Form No. F_011510
18.10.25
TECHNICAL DATA
Capacity
Schedule 10
Schedule 30 (8")
Gal / Ft
L / m
Gal / Ft
0.045
0.559
0.049
0.078
0.969
0.085
0.106
1.316
0.115
0.174
2.161
0.190
0.248
3.080
0.283
0.383
4.756
0.434
0.513
6.370
0.577
0.660
8.196
0.740
1.040
12.915
1.144
1.501
18.640
1.649
2.660
33.032
2.776
Where:
V = Volume
P = Required Air Pressure
T = Fill time (typically 30 min.)
7.48 = gal. / ft.
14.7 = atmospheric pressure
3
)
P65
Table 2 - Air
Pressure Settings
For Systems with Tank-Mounted Compressors:
L / m
Air Maintenance
0.608
Device
1.043
Air Supervisory Switch 25 PSI (1.7 bar)
1.428
2.360
For Systems with Riser Mounted Compressors:
3.515
Compressor
5.390
On/Off Switch
7.165
Air Supervisory
9.190
Switch
14.206
Table 3 - Quick Reference Compressor Size
20.477
Compressor
30.472
Size (HP)
1/6
1/3
1/2
1
Example:
System volume as determined by table 1 = 750 gallons
Required Air pressure = 30 PSI
3
Compressor Size (cfm) =
Vs x P
Vc =
108
2" MODEL G-2000P
DOUBLE INTERLOCK PREACTION
WITH ELECTRIC/PNEUMATIC RELEASE
System Pressure
Up to 175 PSI
175 PSI (12 bar)
(12 bar)
to 250 PSI (17 bar)
30 PSI
(2.1 bar)
30 PSI (2.1 bar) /
50 PSI (3.45 bar) /
40 PSI (2.8 bar)
25 PSI (1.72 bar)
45 PSI (3.10 bar)
Free Air @
Max System Size to
40 PSI (2.8 bar)
Pump to 40 PSI (2.8 bar)
(cfm)
in 30 Minutes (Gal)
1.0
2.0
3.1
5.9
(750 x 30)
7.48 x 14.7 x 30
Metric Units
Where:
Vc = Volume of Cylinder (L)
P = Required Nitrogen Pressure (bar)
V = Volume of System (L)
Page 3 of 12
50 PSI
(3.45 bar)
45 PSI (3.1 bar)
60 PSI (4.1 bar)
90
180
300
600
= 6.8 cfm
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