UNITED Nitrogen Pac SC-W, Установка, наладка, обслуживание

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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
12
1.9 Purge Vent Assemblies. Purge vent assemblies purge gas from the interior of the sprinkler pipe, allowing the Model
SC-W assembly to replace air with 98% pure nitrogen. This assembly should be connected to the sprinkler piping at a
high point in the vicinity of the inspector's test connection. A float valve prevents the escape of water when the
sprinkler valve opens and the sprinkler piping fills with water. A fixed orifice regulates the amount of gas leaving the
pipe. A union facilitates installation and positioning. A strainer helps prevent blockage of the orifice by debris. A
drain plug allows occasional removal of accumulated liquid water. A minimum of one (1) purge vent assembly (PVA)
is required for each sprinkler riser to be filled with nitrogen.
1.9.1. Purge Vent Assembly
– Model PVA-4 (For Manual Purging).
Refer to Figure 7 . The Model PVA-4 Purge Vent
Assembly serves as a connection point for a Model NA-2 N
2
Purity Analyzer - Hand-Held (refer to Appendix A) to
manually measure the purity of nitrogen in the sprinkler pipe. The device includes a built-in exhaust muffler to
minimize the noise of purging gas. The N
2
purity analyzer female connection point is normally closed, and
automatically opens when the male connector of the analyzer is attached.
Figure 7
Purge Vent Assembly
– Model PVA-4 (For Manual Purging)
INLET
BALL VALVE
UNION
STRAINER
FLOAT
VALVE
EXHAUST
N
2
PURITY
ANALYZER
CONNECTION
DRAIN PLUG