TM 9-4120-399-14
5-9. BRAZING / DEBRAZING PROCEDURES. (Continued).
(2) To prepare a joint on a valve for brazing, disassemble the valve to the extent
possible. Then apply heat sink (Appendix E, item 21) to all but the joint. (If heat
sink is not available a wet rag may be used).
(3) Protect insulation, wiring harnesses, and surrounding components with appropriate
shields.
(4) Be sure the work area is well ventilated and that dry nitrogen is flowing through the
refrigeration system at a rate of 1 to 2 cfm (0.028-0.057 m3/minute).
(5) Apply sufficient heat uniformly around the joint to quickly raise it to a temperature
that will melt the filler alloy. Remove heat as soon as brazing is completed.
5-10. LEAK TESTING THE REFRIGERANT SYSTEM.
WARNING
DANGEROUS CHEMICAL
(R22)
is used in this equipment.
DEATH
or severe injury may result if personnel fail to observe safety precautions.
Use great care to avoid contact with liquid refrigerant gas being discharged
under pressure. Sudden and irreversible tissue damage can result from
freezing. Wear thermal protective gloves and a face protector or goggles
in any situation where skin-eye-contact is possible. Prevent contact of
refrigerant gas with flame or hot surfaces. Heat causes refrigerant to
break down and form carbonyl chloride (phosgene), a highly poisonous
and corrosive gas.
WARNING
REFRIGERANT UNDER PRESSURE
is used in the operation of this equipment.
DEATH
or severe injury may result if you fail to observe safety precautions.
Never use a heating torch on any part that contains refrigerant 22. Do
not let liquid refrigerant touch you, and do not inhale refrigerant gas.
a. Supplies. To test the refrigeration system for leaks, you will need the following items.
Nitrogen cylinder (Appendix E, item 2)
Refrigerant 22 (Appendix E, item 17)
