UNITED FIRE SYSTEMS -
NITROGEN-
PAC™
MODEL SC-W
INSTALLATION, COMMISSIONING, AND MAINTENANCE MANUAL
REVISION 1.01 MAR 2021 - P/N 30-NPWICM-000
11
1.8. Nitrogen / Air Maintenance Device
– Model NAMD-1.
Refer to
Figure 6
. The FM Approved Model NAMD-1
Nitrogen / Air Maintenance Device is designed for controlling the nitrogen and / or air pressure from the Model SC-W
assembly into the sprinkler piping. The gas pressure flows through a high-precision pressure regulator capable of
providing accurate regulation over a wide range of inlet pressures and gas flows. Upon activation of a sprinkler
head, the gas pressure will not interfere with the operation of the sprinkler valve or unduly lengthen the time for the
sprinkler piping to fill with water. Manual ball valves allow the device to be bypassed for initial-fill of the piping with
air. A strainer protects the regulator from particulate matter.
Figure 6
Nitrogen / Air Maintenance Device
– Model NAMD-1
PRESSURE GAUGE
BACKFLOW
PREVENTION
OUTLET
SHUTOFF VALVE
OUTLET
(1/2 NPT FEMALE)
BYPASS VALVE
PRESSURE
REGULATOR
STRAINER
INLET
SHUTOFF VALVE
INLET
(1/2 NPT FEMALE)
Summary of Contents for Nitrogen Pac SC-W
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