BRAZING/DEBRAZING PROCEDURES. - TM-5-4120-384-140227

TM5-4120-384-14

5 - 1 3 . BRAZING/DEBRAZING PROCEDURES.

Supplies:

Brazing alloy (silver) (items 9 and 10,

Appendix

Nitrogen cylinder (item 8, Appendix E)

Brazing flux (item 11, Appendix E)

Abrasive cloth (item 12, Appendix E)

Rags (item 13, Appendix E)

General.

All tubing in the refrigeration system is seamless

copper with a bright internal finish that permits thorough cleaning

Rigid

and prevents entrapment of moisture or other impurities.

grade copper is used for straight sections and soft grade for

sections that must be bent.

All interconnecting fittings, such as

The bodies of all valves and

elbows, teess etc., are also copper.

All joints, except

all connectors on other components are brass.

t h o s e p r o v i d e d w i t h f l a r e f i t t i n g s are made by brazing in

accordance with MIL-B-7883, except that radiographic examination is

not required.

Filler Alloy.

Grade IV or VI brazing alloy and Type B flux,

as specified in MIL-B-7883, must be used for all copper to brass

Grade III brazing alloy may be substituted for Grade IV or

joints.

VI for copper to copper joints; flux is not required for copper to

copper joints.

Debrazing.

Debraze joints

for

removal

refrigeration

system components

as follows:

All Refrigerant - 22 must be discharged from the

system and the entire system must be purged with dry

nitrogen before beginning any debrazing operation.

(1) Determine which joints are to be debrazed. Due to

limited work space inside the air conditioner, it may be more

convenient to remove a part of the interconnecting tubing with the

component rather than debrazing joints on the component itself.

(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.

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