TM 9-4120-398-14
This task covers:
Service
INITIAL SETUP
Tools
Equipment Condition
Tool kit, refrigeration SVC
Power OFF
Condenser access door open
Refrigerant Discharged
System nitrogen purged
General Safty Instructions
Materials/Parts
Nitrogen cylinder
WARNING
(Item 9 Appendix E)
Voltages used can kill. Always
Brazing alloy (silver)
disconnect power cord to air conditioner
(Items 2 and 3 Appendix E)
Brazing flux
before performing any internal
maintenance. Shutting unit off at its
(Item 6 Appendix E)
Abrasive cloth
control panel does not disconnect
(Item 4 Appendix E)
unit power.
Rags (Item 12 Appendix E)
Service.
a. General. All tubing in the refrigeration system is seamless copper with a bright internal finish that permits thorough
cleaning and prevents entrapment of moisture or other impurities. Rigid grade copper is used for straight sections and soft
grade for sections that must be bent. All interconnecting fittings, such as elbows, tees, etc., are also copper. The bodies of all
valves and all connections on other components are brass. All joints, except those provided with flare fittings, are made by
brazing in accordance with MILB-7883, except that radiographic examination is not required.
b. Flller Alloy. Grade IV or VI brazing alloy and type B flux, as specified in MIL-B-7883, must be used for all copper to
brass joints. Grade III brazing alloy may be substituted for Grade IV or VI for copper to copper joints; flux is not required for
copper to copper joints.
c. De-brazing. Debraze joints for removal of refrigeration system components as follows:
All refrigerant -22 must be discharged from system and entire system must be purged with dry nitrogen before
beginning any debrazing operation.
