UNITED Nitrogen Pac SC-W, Installation, Commissioning Maintenance

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UNITED FIRE SYSTEMS - NITROGEN-
PAC™
MODEL SC-W
INSTALLATION, COMMISSIONING, AND MAINTENANCE MANUAL
REVISION 1.01 MAR 2021 - P/N 30-NPWICM-000
61
NOTES
A = NORMAL
– system is providing nitrogen into preaction sprinkler system(s).
B = BYPASS
– compressed air is routed to preaction sprinkler system(s) for initial fill (max. 30 minutes) per NFPA 13, or
to put sprinkler system on air if nitrogen is not available
C = PURGE
– system(s) are purging air out of sprinkler piping, replacing air with nitrogen.
D = FILTER SERVICE
– filter elements in Model SC-W cabinet filters are to be replaced.
E = N
2
PURITY AT TEST PORT
– nitrogen purity at Model SC-W cabinet is to be checked with NA-2 hand-held meter.
F = N
2
PURITY AT PVAs
– nitrogen purity at PVAs is to be checked with NA-2 hand-held meter or TAP device.
G = DRAIN
– draining accumulated moisture from Model SC-W.
A B C D E F G
VALVE NORMAL BYPASS PURGE
FILTER
SERVICE
N
2
PURITY AT
TEST PORT
N
2
PURITY
AT PVAs
DRAIN
MODEL SC-W VALVES
1
Open
(handle
facing UP)
Closed
(handle
facing
LEFT)
Open
(handle
facing
UP)
Open
(handle
facing
UP)
Open
(handle facing
UP)
Open
(handle
facing UP)
Open
(handle
facing UP)
2 Open Open Open Closed Open Open Closed
MODEL NAMD-1 VALVES
NAMD-1 Inlet Open Closed Open Open Open Open Open
NAMD-1 Outlet Open Closed Open Open Open Open Open
NAMD-1 Bypass Closed Open Closed Closed Closed Closed Closed
MODEL PVA INLET VALVE(S)
PVA-4 Inlet
Valve(s) with NA-2
Closed Closed Open Closed Closed Open Closed
PVA-2 Inlet
Valve(s) with TAP
Open Open Open Open Open Open Closed
TAP = True Advanced Purge device. Leave PVA inlet valve OPEN unless draining water at PVA location. TAP device
will be in control of purging.
Table 11
Quick-Reference Valve Position Table