Quantcast BRAZING/DEBRAZING PROCEDURES (Continued) 4120-01-069-1321)">

 

Click here to make tpub.com your Home Page

Page Title: BRAZING/DEBRAZING PROCEDURES (Continued)
Back | Up | Next

Click here for thousands of PDF manuals

Google


Web
www.tpub.com

Home


   
Information Categories
.... Administration
Advancement
Aerographer
Automotive
Aviation
Construction
Diving
Draftsman
Engineering
Electronics
Food and Cooking
Logistics
Math
Medical
Music
Nuclear Fundamentals
Photography
Religion
   
   

 

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Back
BRAZING/DEBRAZING PROCEDURES - 506780110
Up
TM-5-4120-359-14 Air Conditioner Split Package 18 000 BTU/HR Cooling 30 000 BTU/HR Heating 208 Volt 3 Phase 400 Hertz Manual
Next
LEAK TESTING THE REFRIGERANT SYSTEM - 506780112
TM 5-4120-359-14
b. 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 joints, Grade III brazing may be substituted for Grade IV or VI for copper to copper joints; flux is not required for
copper to copper joints.
c.
Debrazing. Debraze joints for removal of refrigeration system components as follows:
WARNING
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 the 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 the 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 rag to act as a heat sink.
WARNING
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, cabinet and other surrounding 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 less than 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 from debrazed joints before reassembly. Heat each
piece of the joint until the filler alloy is melted and then wipe it away with a damp cloth. Be sure no filler alloy or other
debris are left inside any tubing, fitting or component.
e. 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 component before reinstallation.
f.
Brazing. Braze joints within the air conditioner as follows:
(1) Position the component to be installed.
(2) To prepare a joint on a valve for brazing, disassemble the valve to the extent possible. Then wrap all but the
joint with a wet rag to act as a heat sink.
(3) Protect insulation, wiring harnesses, and surrounding 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 less than 1 - 2 cfm (0.028-0.057 m3/minute).
(5) Apply sufficient heat uniformly around the joint to quickly raise it to a temperature that will melt the filler alloy.
Remove heat as soon as brazing is completed.
4-29

Privacy Statement - Press Release - Copyright Information. - Contact Us

Integrated Publishing, Inc.