ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
5.14. EVACUATING REFRIGERANT SYSTEM. Continued
SERVICE - continued
The refrigeration system must be evacuated to remove all moisture before it is charged
with refrigerant R-22. Check that system was leak tested and has NO LEAKS
If compressor was replaced as result of a burnout, check that compressor burnout
Check that both charging manifold valves are closed
Remove yellow 3/8-inch (0.95 cm) hose from hose rack and connect to vacuum pump
Remove 1/4-inch (0.64 cm) yellow hose from hose rack and connect to R-22 refrigerant cylinder positioned for
e. Open R-22 refrigerant cylinder. Loosen 1/4 inch (0.64 cm) yellow hose at charge port and purge for 3-5
seconds, then tighten.
f. Open VPU CGV, and PGV.
g. Start vacuum pump end open ballast valve (on vacuum pump) one turn.
h. Observe vacuum pump gauge for a reading of 29-30 inches of Hg,
i. Close VPV and open CV and add refrigerant until compound and pressure gauges read approximately and 2
psig (4.41 kg), then clove CV.
j. Stop vacuum pump and close ballast valve.
k. Allow refrigerant to remain in system for 1 hour.
Refrigerant will act as a blotter for moisture. One hour is recommended time for
maximum moisture removal. Shorter blotting period can be used if it is known that
system is relatively dry.
Repeat Steps g through k.
Repeat Steps j and k.
Close VPV and CGV.
Stop vacuum pump.
Disconnect hose from vacuum pump and return it to racks. Charge refrigeration system (paragraph 5.15).