|
| |
TM 10-4130-239-14
5-5.
REFRIGERATION SYSTEM SERVICE
- BRAZING/DEBRAZING (CONT)
3.
protect insulation, wiring harness, sheet metal and other
surrounding components with proper shields.
4.
Be sure to do the work in a well ventilated area, and have dry
nitrogen flowing through the refrigerant system (see paragraph
5-4) .
5.
Apply enough heat uniformly around the joint to melt the filler
alloy quickly.
If heat is applied slowly, or only on one side,
the, entire component or length of tubing will be heated and filler
allow in adjacent joints may also be melted or weakened.
Remove
heat as soon as the joint separates.
1.
Clean the mating surfaces and adjacent areas of all parts to be
joined, remove all oil, grease, paint, dirt, scale, artificial
oxide films, or any other foreign substances.
Old filler alloy
must be cleaned from debrazed joints before reassembly as best as
possible.
Heat each piece of the joint until the filler alloy is
melted and then wipe it away with a dry rag.
Use abrasive cloth
and tubing wire brushes to clean the outside and inside joints
respectively.
Be sure no filler alloy or other debris is left
inside any tubing, fitting or component.
2.
Remove burrs to permit proper fitting of parts and flow of filler
material.
Unless otherwise specified, the clearance shall not
exceed 0.006 inch (.15 mm).
NOTE
Grade IV or VI brazing alloy and Type B flux, as
specified in MIL-B-7883, must be used for
copper to copper joints and all copper to
joints.
Grade III brazing alloy may be
substituted for Grade IV or VI for copper
copper joints.
3.
Use the following as a guide for brazing:
all
brass
to
a. To prepare a joint on a valve for brazing, disassemble the
valve as completely as possible.
Then wrap all but the joint
with a wet rag for a heat sink.
Place tubing and/or components
in water chiller in assembled position.
b. Ensure that the unit is being purged with nitrogen per
paragraph 5-4.
5-10
|
