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1. Removal of residual
refrigerant.
Precautions
Items
9-3. Practical Work for Heavy Repair
2. Nitrogen blowing
welding.
※
KEYPOINTING
Welding without nitrogen blowing produces oxidized scales inside
a pipe, Which affect on performance and reliability of a product.
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 (dryer part) with a nipper and then cut low pressure side.
* When replacing a dryer:
Weld
①
and
②
parts by blowing nitrogen (0.1~0.2kg/cm2) to high
pressure side after assembling a dryer.
* 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.
