Component Maintenance Manual
EFFECTIVITY: ALL
21-00-22
Page
11001
JULY 21, 2011
SPECIAL PROCEDURES
TASK 21-00-22-82-801
12.0 SPECIAL PRODECURES
SUBTASK 21-00-22-82-001
12.1
Expansion Valve Alignment:
12.1.1
The expansion valve is set at the factory, but there may be times when it must be adjusted
to assure proper refrigerant flow at the desired evaporating temperature; for example,
excessive pressure drop for long suction line runs. Any adjustment must not affect typical
suction and discharge pressures as outlined in Table 4.
12.1.2
Tools, fixtures, equipment, or consumable items required:
Small hand tools and socket set
Micrometer
Scribe or wire hook
Volt-OHM meter (digital)
Shop air, 40 PSIG max
Respiration
mask
External aircraft power source
Inspection
mirror
Thermometer, 0-150° F
Flashlight or service lamp
R12 service manifold and gauge set
12.1.3
Verify that system leak check and refrigerant charging has been performed and system is
operating at typical values as outlined in table 4.
Outside Air Temperature
Suction Pressure
Discharge Pressure
(Deg F)
(PSIG)
(PSIG)
60-70
28
125 - 140
80 30
170
±10
95
31
210 ± 10
105
32
237 ± 10
Table 4 Typical Operating Values
