TM 9-4110-256-14
5-10.
BRAZING/DEBRAZE PROCEDURE. - Continued
WARNING
Never use a heating torch on any part that contains refrigerant. Heat may cause the refrigerant to
decompose and release irritating, toxic, and corrosive gases. All refrigerant must be discharged
from the system and the entire system must be purged with dry nitrogen before beginning any
brazing operation.
CAUTION
If heat is applied slowly, or only on one side, the entire component or length of tubing will be
heated and filler alloy in adjacent joints may also be melted.
(3)
Check that the system is being purged (para 5-9) and apply sufficient heat uniformly around the joint to
quickly melt the filler alloy. Remove heat as soon as the joint is separated.
b.
Clean. All filler alloy must be cleaned from debrazed joints before reassembly. Heat each piece of the joint until
the filler is melted and them wipe it away with a wire brush. Be sure no filler alloy or other debris is left inside
any tubing, fitting, or component. Use abrasive cloth as necessary to clean joints.
c.
Braze.
(1)
Protect wiring harnesses and other components with appropriate heat shields.
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 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.
(2)
If brazing a joint on a valve, disassemble the valve to the extent possible and wrap all but the joint with a
wet rag to act as a heat sink.
5-18
