Mitsubishi Electric City Multi PURY-EM200YNW-A1, Service Handbook

Page: 25 / 503

[1-3 Working with Refrigerant Piping ]
14 -
chapter 1 BS_01_L
1
Che
ck Bef
o
re
Se
rvicing
1-3 Working with Refrigerant Piping
1-3-1 Pipe Brazing
Perform brazing with special care to keep foreign objects (such as oxide scale, copper powder, water, and dust) out of the refrig-
erant system.
Example: Inside the brazed connection
1. Items to be strictly observed
 Do not conduct refrigerant piping work outdoors if raining.
 Use inert gas during brazing.
 Use a brazing material (BCuP-3) that requires no flux when brazing between copper pipes or between a copper pipe and
copper coupling.
 If installed refrigerant pipes are not immediately connected to the equipment, then braze and seal both ends.
2. Reasons
 Refrigerant oil is highly hygroscopic and is likely to cause unit failure if moisture infiltrates into the system.
 Residual flux in the refrigerant circuit will cause sludge to form.
3. Notes
Do not use commercially available antioxidants because they may cause the pipes to corrode or refrigerating machine oil to
deteriorate.
Use of no inert gas during brazing Use of inert gas during brazing
0000006448.BOOK 14 ページ ２０２１年１０月６日 水曜日 午後１時５７分