BRAZING/DEBRAZING PROCEDURES.-Continued

TM5-4120-383-14

5-13.

BRAZING/DEBRAZING

PROCEDURES.-Continued

(2) Before debrazing a joint on a valve, disassemble the

valve to the extent possible, then wrap all but the joint with a

wet cloth to act as a heat sink.

The polyurethane foam used as insulation in the air

conditioner will break down to form toxic gases if

exposed to the flame of a torch or brazing

temperature.

(3) Protect insulation, wiring harnesses, and other

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 - 2 cfm (0.028 - 0.057 m3/minute).

(5) Apply sufficient heat uniformly around the joint to

quickly melt the filler alloy.

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.

Remove heat as soon as the joint separates.

d. Cleaning Debrazed Joints. All filler alloy must be cleaned

Heat each piece of the

from debrazed joints before reassembly.

joint until the filler alloy is melted and then wipe it away with a

Be sure no filler alloy or other debris is left inside

wire brush.

any tubing, fitting, or component.

Reassembly.

If tubing sections or fittings were removed

with a component, debraze them from the component, clean the

joints, and braze them to the new components before reinstallation.

Brazing.

Braze joints within the air conditioner as

follows:

(1) Position component to be installed.

(2) TO prepare for brazing a joint on a valve, remove the

electric coil.

(3) Protect insulation, wiring harnesses, and surrounding

components with appropriate shields.

(4) Be sure work area is well ventilated and that dry

nitrogen is flowing through the refrigeration system at a rate of

1 - 2 cfm (0.028 - 0.057 m3/minute).

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