Practical Work For Heavy Repair - Daewoo FRS-U20DD. Service Manual

10-3. Practical Work for Heavy Repair

Items
1. Removal of residual
refrigerant.
2. Nitrogen blowing
welding.
1) Remove residual refrigerant more than 5 minutes later after
turning off the refrigerator. ( If not, compressor oil may leak inside.)
2) Remove retained refrigerant slowly by cutting first high pressure
side (drier part) with a nipper and then cut low pressure side.
Suction tube
Compressor
Process tube
Discharge tube
③
Compressor
Process tube
④
* When replacing a drier:
Weld 1 and 2 parts by blowing nitrogen (0.1~0.2kg/cm2) to high
pressure side after assembling a drier.
* When replacing a compressor:
Weld 3 and 4 parts by blowing nitrogen to the low pressure side.
Note) For other parts, nitrogen blowing is not necessary because it
does not produce oxidized scales inside pipe because of its short
welding time.
- KEYPOINTING
Welding without nitrogen blowing produces oxidized scales inside
a pipe, Which affect on performance and reliability of a product.
68
Precautions
Evaporator
Low pressure
side
Hot Pipe
High Pressure side
Condenser
Evaporator
Low pressure
side
Hot Pipe
High Pressure side
Condenser
Dryer
②
Dryer
①