VC Pro VRF 50/60Hz     
162     
Midea VC Pro Series Engineering Data Book 
5 Refrigerant Piping Installation 
5.1 Procedure and Principles 
5.1.1 Installation procedure 
 
 
5.1.2 Three principles for refrigerant piping 
 
Notes: 
1.  See Part 3, 5.2.1 “Pipe delivery, storage and sealing”. 
2.  See Part 3, 5.5 “Brazing”. 
3.  See Part 3, 5.8 “Pipe Flushing”. 
4.  See Part 3, 5.10 “Vacuum Drying”. 
5.  See Part 3, 5.3 “Manipulating Copper Piping”. 
6.  See Part 3, 5.9 “Gastightness Test”. 
   
Installation of the refrigerant piping system should proceed in the following order: 
 
 
 
 
Note: Pipe flushing should be performed once the brazed connections have been completed with the exception of the 
final  connections  to  the  indoor  units.  That  is,  flushing  should  be  performed  once  the  outdoor  units  have  been 
connected but before the indoor units are connected. 
Pipe brazing 
and installation 
Particles such as oxide produced 
during brazing and/or building dust 
can lead to compressor malfunction 
Moisture can lead to ice formation or 
oxidization of internal components 
leading to abnormal operation or 
compressor damage 
  Seal piping during storage
1
 
  Flow nitrogen during brazing
2
 
  Pipe flushing
3
   
  Pipe flushing
3
 
  Vacuum drying
4
   
Imperfect seals can lead to refrigerant 
leakage 
  Pipe  manipulation
5
  and  brazing
2
 
techniques 
  Gastightness test
6