weekly. In the schematic in figure 2-3, the nitrogen
( N2) supply cylinder is located on the right side
of the test stand and is connected to the N2
input connector. When you open the supply
cylinder valve, nitrogen flows to the high-pressure
regulator (Q) and the low-pressure regulator
( N ).
PRESSURIZING THE
SUPPLY NITROGEN SYSTEM
The pressure in the supply cylinder is indicated
on the supply pressure gage (9). (This gage also
tells you when your supply cylinders need
replacing.) If you secure all the other valves on
the test stand, the system should have no leaks
beyond this point. To test for leakage, read the
pressure on the supply pressure gage and wait 2
minutes. No drop in pressure should be indicated.
At this point, you should leave all valves and
connections in their present position. Your supply
nitrogen system is pressurized, and you are setup
to proceed to the leakage test for the next
system.
REGULATED HIGH-PRESSURE
SYSTEM
This system supplies regulated high-pressure
nitrogen to the following valves, gages, and
connections, as shown in figure 2-4.
High-Pressure Regulator (Q)
Regulated High-Pressure Gage (10)
Regulated Low-Pressure Gage (11)
Gage Guard that protects the Low-Range
and High-Range Leakage Rotameters.
(Although this is not part of this system,
the pressure is allowed to enter through the
gage guard set at 170 ± 5 psig.)
System Bleed Valve (S)
Vent Pressure Valve (H)
Inlet Pressure ON/OFF Valve (L)
Tee Connector (inside chamber) (28)
N2 Input Connector (inside chamber) (18)
Gage Guard for the N2
(set at 145 ± 5 psig)
N2 Input Gage (27)
input pressure gage
Figure 2-3.—Model 1172AS100 supply nitrogen system.
2-4
