2. Position the selector valve (20) to BOOST.
WARNING
3. Open the oxygen cylinder valve (4).
Do not use this unit except for oxygen servicing.
Do not interchange or substitute any components
4. Open the nitrogen cylinder valves (3), and
of this system with those of other systems. To do
nitrogen will flow to the nitrogen supply
so may either cause an explosion or contaminate
pressure gauge (6) and valve (7).
this system. Always open all valves slowly. If a
5. Verify that the nitrogen supply pressure gauge
leak is discovered during any phase of operation,
(6) indicates a pressure greater than 200 psi. If it
immediately shut down the system.
indicates less than 200 psi, recharge the gaseous
nitrogen system.
6. Open the nitrogen supply valve (7), allowing
Direct Servicing From The Oxygen
nitrogen to flow through the filter (8) and preset
Cylinder.--When charging an external system
regulator (9) to the boost pump drive valve (15).
directly from the oxygen cylinder using pressure
The boost pump drive pressure gauge (12)
equalization, follow these steps:
should indicate 115 to 125 psi.
1. Prepare the unit for operation as previously
7. Open the boost pump drive valve (15), which
described.
allows nitrogen to flow to the boost pump. The
NOTE: The number in parentheses following a
boost pump (21) should begin to operate. The
component name refers to figure 10-13.
pilot valves will function to control the
2. Open the oxygen cylinder valve (4), and observe
operation of the boost pump as previously
the oxygen supply pressure gauge (19). Ensure
described.
oxygen pressure is adequate as previously
8. Verify that a pressure of 2,300 to 2,500 psi is
describe.
indicated on the oxygen module regulator inlet
3. Position the selector valve (20) to BYPASS,
pressure gauge (29).
allowing oxygen to flow through the purifier
9. Rotate the handle of the oxygen regulator (30)
(26) and filter (27) to the pressure regulator (30).
clockwise until the regulator outlet gauge (31)
Oxygen cylinder pressure should be indicated
indicates the desired pressure.
on the regulator inlet pressure gauge (29).
10. Purge the servicing hose assembly, and continue
4. Rotate the pressure regulator (30) handle
with the servicing operation as previously
clockwise until the regulator outlet pressure
described.
gauge reads the desired servicing pressure.
Boost Pump Using Air Drive.--When using
5. Purge the servicing hose (33) by opening the
compressed air to drive the boost pump during an
servicing hose valve (34) for a few seconds, and
external charging operation, follow these steps:
then attach the servicing adapter (36 or 38) to the
system to be charged.
1. Prepare the unit for operation as previously
described.
6. Begin delivering oxygen to the aircraft system
by opening the servicing hose valve (34).
2. Position the selector valve (20) to BOOST.
7. When the aircraft system gauge indicates the
3. Open the oxygen cylinder valve (4).
desired pressure, close the servicing hose valve
(34).
CAUTION
8. If no other system is to be serviced immediately,
Use clean dry compressed air for boost pump
s h u t t h e u n i t d ow n a s d e s c r i b e d u n d e r
drive. Ship/shop air pressure ranges 90 to 150 psi.
SHUTDOWN PROCEDURES.
Purge the air line before connecting it to the
Boost Pump Using Nitrogen Drive.--When
servicing unit.
using nitrogen to drive the boost pump during an
external charging operation, follow these steps:
4. Purge the ship/shop air supply hose, connect the
1. Prepare the unit for operation as previously
described.
air hose to nitrogen module ship air connection
10-34
