CHAPTER 5 Flashcards
(30 cards)
The concentrator is designed to provide
supply of breathing oxygen for two aircrewmembers’ open loop breathing schedules up to 50,000 feet.
The GGU-12/A oxygen concentrator consists of
an air heater assembly, inlet filter assembly, pressure reducer assembly, rotary valve assembly, two molecu- lar sieve beds, a plenum assembly, a thermal resistor, a junction box assembly, a thermostatic switch, and a shroud.
The GGU-12/A oxygen concentrator uses
engine bleed air and electrical power from the aircraft and provides oxygen-enriched air for aircrewmember breathing.
The regeneration by desorption of nitrogen in the vented bed is enhanced by
a reverse flow of oxygen- enriched gas from the output or product end of the pressurized bed.
The amount of the reverse purge flow through the vented bed is controlled
by the purge orifice connecting the output ends of the two beds. The two beds are cycled alternately between pressurization or oxygen producing mode and the vented, regenerative mode by the motor driven rotary valve.
The output oxygen-enriched product gas from the pressurized bed flows into
the plenum assembly and through check valves at the outlet of each sieve bed preventing backflow.
The oxygen-enriched product gas from the con- centrator flows through
a filter and then to the aircrew breathing system.
Mounting
2 index pins,2 captive fasteners used for aircraft mounting
Voltage
115Vac,400Hz,6amps(max)
Heater
1 unit with air heater overtemperature indicator
Filter
0.6Micron
Inlet Pressure Range
8 to 250 psig, 50 psig preferred
Pressure Reducer
Cut in at 50 psig inlet pressure and increases to 85 5 psig at 250 psig inlet pressure
Relief Valve
125 psig outlet pressure
Rotary Valve
6.35RPM (continuousrotation)
Sieve Beds
Two unit, molecular type
Plenum
Oxygen enriched air storage
Junction Box
Power supply for heater and rotary valve
Operating Altitude Range
Sea level to 50,000 feet
Operating Temperature
-65 to +165F
oxygen concentrator
Overall Dimensions:
Length: 13 3/4inches
Width: 8 2/3inches
Height: 10 1/3inches
Weight: 37.5lbs.
GGU-12/A oxygen concentrators which do not pass inspection and cannot be adjusted in the aircraft shall be
removed and replaced with a Ready-For- Installation (RFI) GGU-12/A oxygen concentra- tor. The replaced oxygen concentrator shall be for- warded to AIMD/MALS for Bench Test and Repair.
The Turnaround/Pre- flight/Postflight/Transfer Inspections are performed
in conjunction with the aircraft inspection requirements for the aircraft in which the GGU-12/A oxygen con- centrator is installed.
The Acceptance/Special/Daily Inspections shall be performed
in conjunction with the aircraft inspection requirements for the aircraft in which the GGU-12/A oxygen concentrator is installed using ap- plicable aircraft technical publications and mainte- nance requirement cards.
