TM9-4120-400-14
BRAZING/DEBRAZING PROCEDURES. - continued
5-12.
Never use a heating torch on any part that contains refrigerant. Heat causes the
refrigerant to break down and form carbonyl chloride (phosgene), a highly toxic and
corrosive gas. All refrigerant must be discharged from the system and the entire system
must be purged with dry nitrogen before beginning any debrazing operation.
NOTE
All joints, except those provided with flare fittings, are made by brazing in accordance with
MIL-B-7883, except that radiographic examination is not required.
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 Ill brazing alloy maybe substituted for Grade IV or VI for
copper to copper joints; flux is not required for copper to copper joints.
If brazing a joint on a valve, disassemble the valve to the extent possible and wrap all but the joint with a wet
3.
cloth to act as a heat sink.
NOTE
If interconnecting tubing was removed with a component, braze tubing to the new
components before reinstallation.
Position component or assembly into place.
5.
Apply sufficient heat uniformly around the joint to quickly melt the filler alloy. If heat is applied slowly, or only on
6.
one side, the entire component or length of tubing will be heated and filler alloy in adjacent joints may also be
melted. Remove heat as soon as brazing is completed.
NOTE
FOLLOW-ON MAINTENANCE:
Remove service manifold (para 5-9).
5-32
