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12.5 Piping installation of R32
12.5.1 Pipe materials used and flaring
Copper pipes are used for refrigerant piping. Pipes
which comply with JIS Regulations need to be used.
Room air conditioners which use R410A and R32
have higher pressure; thus, using pipes which comply
with the Regulations is important.
The pipe thickness is regulated by revised JIS B 8607
“Flaring and brazing fittings for refrigerant” and the
pipe thickness for R410A, R32 is shown in the table.
Pipe thickness
O and OL materials
Thickness (mm)
Diameter
Diameter
(mm)
R410A
R32
R22
1/4
6.35
0.80
3/8
9.52
0.80
1/2
12.70
0.80
5/8
15.88
1.00
Caution
For connection piping, use copper phosphate seamless pipes (1220T) as regulated in “JIS H 3300” and the pipe
thickness is 0.8 mm.
In the market, there are some pipes of 0.7 mm thickness, but do not use these pipes (0.8 mm thickness has to be
strictly followed).
It is recommended to use pipes whose adhesion amount of oil is at or less than 40 m
g
/ 10 m.
At the same time, do not use pipes with dent, de-shape, and color change (especially inside).
12.5.2 Processing and connection of pipes
For refrigerant pipe installation, be aware of moisture and dirt do not get into the pipes, and make sure of no
refrigerant leakage.
◎
The procedure of flaring and precautions
a) Cutting of pipes
：
use pipe cutter and cut the pipe slowly not to de-shape the pipe.
b) Removal of burrs on the edge of pipe (reamer or scraper)
If the condition of pipe edge after the deburring is no good or if burrs attaches on the flaring, it may cause
refrigerant leakage. Turn the pipe end down and perform deburring carefully.
c) Insert the flare nut (use the nut which is a part of the CZ parts)
d) Flaring
Ensure the cleanliness of clump bar and pipe, and perform flaring carefully.
Use the existing flare tools or flare tools for R410A. Be aware that the sizes and dimensions of flaring is different
in each flaring tool. If you use the existing flaring tools, use flaring gauge to measure the length of the flaring part.
Piping
size
(mm)
Dimensions “a” (mm)
R22
Dimensions “a” (mm)
R410A/R32
a
Bar
Nut outer diameter (mm)
Flare tools
Flare tools
for R410A
Flare tools
Flare tools
for R410A
R22
R410A
Clutch type
Wing nut
type
Clutch type Clutch type
Wing nut
type
Clutch type
R32
6.35 (1/4")
0.5 ~ 1.0
1.0 ~ 1.5
0 ~ 0.5
1.0 ~ 1.5
1.5 ~ 2.0
0 ~ 0.5
17
17
9.52 (3/8")
0.5 ~ 1.0
1.0 ~ 1.5
0 ~ 0.5
1.0 ~ 1.5
1.5 ~ 2.0
0 ~ 0.5
22
22
12.70 (1/2")
0.5 ~ 1.0
1.5 ~ 2.0
0 ~ 0.5
1.0 ~ 1.5
2.0 ~ 2.5
0 ~ 0.5
24
26
15.88 (5/8")
0.5 ~ 1.0
1.5 ~ 2.0
0 ~ 0.5
1.0 ~ 1.5
2.0 ~ 2.5
0 ~ 0.5
27
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