Midea VC Pro Series

VC Pro VRF 50/60Hz
167
Part 3 - System Design and Installation
… box continued from previous page
Piping orientation during brazing
Brazing should be conducted downwards or horizontally to avoid filler leakage.
Figure 3-5.6: Piping orientation during brazing
Piping overlap during brazing
Table 3-5.3 specifies the minimum permissible piping overlap and the range of permissible gap sizes for brazed joints
on piping of different diameters. Refer also to Figure 3-5.7.
Figure 3-5.7: Piping overlap and gap for brazed joints
Legend
A
Inner diameter of larger pipe
D
Outer diameter of smaller pipe
B
Inlaid depth (overlap)
Table 3-5.3: Piping overlap and gap for brazed joints
1
D (mm)
Minimum
permissible B
(mm)
Permissible A – D
(mm)
5 < D < 8
6
0.05 - 0.21
8 < D < 12
7
12 < D < 16
8
0.05 - 0.27
16 < D < 25
10
25 < D < 35
12
0.05 - 0.35
35 < D < 45
14
Notes:
1. A, B, D refer to the dimensions shown in Figure 3-5.7.
Filler
 Use a copper/phosphorus brazing alloy (BCuP) filler that does not require flux.
 Do not use flux. Flux can cause corrosion of piping and can affect the performance of compressor oil.
 Do not use anti-oxidants when brazing. Residue can clog piping and damage components.