The pressure operated shutoff pilot valve (24) is a
NOTE: The number in parentheses following a
normally open (NO) oxygen module safety device,
component name refers to figure 10-13.
which limits the boost pump (21) maximum output
Regulator Inlet Pressure Gauge.--The regulator
pressure. When the pressure of oxygen discharged
inlet pressure gauge (29) displays the pressure at the
from the boost pump (21) exceeds 2,400 psi, the pilot
inlet side of the oxygen regulator. It is located to the
valve (24) closes and shuts off the pump gaseous
right of the oxygen supply pressure gauge on the
nitrogen or compressed air drive. The pilot valve (24)
oxygen module control panel. (See figure 10-16, front
opens when oxygen pressure discharged from pump
view.)
falls below 1,900 psi. This pilot valve (24) also
provides semiautomatic on/off control of the pump.
Pressure Regulator.--The pressure regulator
During pump operation, if the oxygen discharge line is
(30) controls the pressure of the gas delivered to the
closed by the servicing valve (34) and the discharge
servicing line. It is located to the right of the regulator
oxygen pressure exceeds 2,400 psi, the pilot valve (24)
inlet pressure gauge on the oxygen module control
shuts off the pump (21). Opening the servicing valve
panel. (See figure 10-16, front view.)
(34) reduces the pump (21) gaseous oxygen discharge
Regulator Outlet Pressure Gauge.--The
to less than 1,900 psi, and the pump (21) starts
regulator outlet pressure gauge (31) displays the
operating.
pressure at the outlet side of the oxygen regulator. It is
Relief Valve.--The relief valve (25) vents excess
located to the right of the pressure regulator on the
pressure if the boost pump (21) outlet pressure exceeds
oxygen module control panel. (See figure 10-16, front
2,900 psi. It is located inside the oxygen module. (See
view.)
figure 10-16, rear view.)
Oxygen Service Connection.--Located on the
right side of the oxygen module, the oxygen service
WARNING
connection (32) provides a means of attaching a
servicing hose to the servicing unit. (See figure 10-16,
Do not use a nitrogen serving unit desiccant
right side view).
cartridge on an oxygen servicing unit. While they
look the same, they are not interchangeable.
S E RV I C I N G A N D I N T E R FAC E E QU I P -
Ensure that the cartridge used on the oxygen
MENT.--The servicing and interface equipment
servicing unit is specifically designed for oxygen
consist of those parts required to connect the oxygen
use.
servicing unit to the aircraft oxygen storage system and
includes the grounding cable reel assembly. The
interface equipment consists of connecting hoses
Purifier.--The purifier (26), located inside the
between the oxygen/nitrogen modules that convey air
oxygen module (figure 10-16, rear view), removes
or nitrogen to drive the oxygen boost pump. The
moisture and other contaminant from the oxygen
entering the servicing line. The purifier assembly is
servicing and interface equipment include the
identical in appearance to the purifier used on the
following items: (See figure 10-18.)
n i t r o g e n s e r v i c i n g u n i t ; h ow ev e r, i t i s n o t
NOTE: The number in parentheses following a
interchangeable. Always use only the item (part
component name refers to figure 10-13.
number) specified in the maintenance manual.
Servicing Hose.--The servicing hose (33)
NOTE: The number in parentheses following a
transfers the oxygen from oxygen servicing unit to the
component name refers to figure 10-13.
aircraft system being serviced.
Filter.--The filter (27) traps foreign matter not
Servicing Hose Valve.--The servicing hose valve
removed by the purifier. It is a 10-micron, replaceable
(34) controls the flow of oxygen from the servicing
element filter located underneath the panel of the
hose to the system being charged.
oxygen module. (See figure 10-16, rear view.)
S e r v i c i n g A d a p t e r s . -- To p r e v e n t o v e r
Oxygen Vent Valve.--The oxygen vent valve (28)
pressurizing aircraft oxygen storage systems,
provides a means of venting gas pressure upstream of
servicing adapters are attached to the servicing hose
the regulator (30). It is a two-position (OFF/VENT)
valve (34). The low-pressure adapter (36), which is
valve located on the upper right corner of the oxygen
module control panel. (See figure 10-16, front view.)
used when servicing low-pressure systems, contains a
10-31
