TM 9-4120-399-14
5-20. PRESSURE REGULATING VALVE.
This Task Covers:
c. Installation
b. Test
a. Removal
Initial Setup:
Tools Required
Tool kit, Refrigeration
Material's Required
None
Equipment Condition
Air conditioner shut down and cool.
a. Test.
(1) Valves are factory set to start opening when suction pressure decreases to 58 psig.
Do not adjust.
(2) Perform a refrigeration pressure check on unit in accordance with para. 5-13. Leave
the service manifold attached.
NOTE
To test, ensure that unit is in bypass cycle.
(3) Set temperature control thermostat knob fully WARMER (clockwise), start air
conditioner in COOL mode, and observe pressure gages. Suction pressure should drop to a
minimum 35 psig (13F) shortly after compressor starts, and then remain constant.
(4) If suction pressure remains at 50-60 psig, replace pressure regulating valve.
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