Midea 
V6-i Series Engineering Data Book
 
4.6 Branch Joints 
 
 
4.7 Pipe Flushing 
4.7.1 Purpose 
To remove dust, other particles and moisture,  which  could cause compressor  malfunction if not flushed out before the 
system is run, the refrigerant piping should be flushed using nitrogen. As described in Part 3, 4.1.1 “Installation procedure”, 
pipe  flushing  should  be  performed  once  the  piping  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. 
 
   
 Use  U-shaped  branch  joints  as  specified  on  the 
construction drawings  –  do  not replace U-shaped  branch 
joints with tee joints. 
Indoor branch joints may be installed either horizontally or 
vertically. Horizontal branch joints must be installed at an 
angle to the horizontal not exceeding 10° in order to avoid 
uneven  distribution  of  refrigerant  and  possible 
malfunction. Refer to Figure 3-4.8. 
To  ensure  even  distribution  of  refrigerant,  a  limitation  is 
placed  on  how  close  branch  joints  may  be  installed  to 
bends,  other  branch  joints  and  the  straight  sections  of 
piping leading to indoor units. Refer to Part 3, 3.6
Figure 3-4.8: Branch joint orientation