4
OCH760
2
Dimensions of flare cutting and flare nut
The component molecules in HFC refrigerant are smaller compared to conventional refrigerants. In addition to that,
R410A is a refrigerant, which has higher risk of leakage because its working pressure is higher than that of other refrig
-
erants. Therefore, to enhance airtightness and strength, flare cutting dimension of copper pipe for R410A has been
specified separately from the dimensions for other refrigerants as shown below. The dimension B of flare nut for R410A
also has partly been changed to increase strength as shown below. Set copper pipe correctly referring to copper pipe
flaring dimensions for R410A below. For 1/2 and 5/8 inch pipes, the dimension B changes.
Use torque wrench corresponding to each dimension.
1/4
3/8
1/2
5/8
3/4
6.35
9.52
12.70
15.88
19.05
9.1
13.2
16.6
19.7
—
9.0
13.0
16.2
19.4
23.3
Nominal
dimensions (inch)
Flare cutting dimensions
Outside
diameter
Dimension A ( )
+0
-0.4
(mm)
R410A
R22
(mm)
1/4
3/8
1/2
5/8
3/4
6.35
9.52
12.70
15.88
19.05
17.0
22.0
26.0
29.0
—
17.0
22.0
24.0
27.0
36.0
Nominal
dimensions (inch)
Flare nut dimensions
Outside
diameter
Dimension B (mm)
R410A
R22
(mm)
Dimension A
Dimension B
1-3. Cautions for refrigerant piping work
New refrigerant R410A is adopted for replacement inverter series. Although the refrigerant piping work for R410A is same
as for R22, exclusive tools are necessary so as not to mix with different kind of refrigerant. Furthermore as the working
pressure of R410A is 1.6 times higher than that of R22, their sizes of flared sections and flare nuts are different.
1
Thickness of pipes
Because the working pressure of R410A is higher compared to R22, be sure to use refrigerant piping with thickness
shown below. (Never use pipes of 0.7 mm or below.)
1/4
3/8
1/2
5/8
3/4
7/8
1
6.35
9.52
12.70
15.88
19.05
22.2
25.4
0.8
0.8
0.8
1.0
1.0*
1.0*
1.0*
0.8
0.8
0.8
1.0
1.0
1.0
1.0
Nominal
dimensions (inch)
Diagram below: Piping diameter and thickness
Outside
diameter (mm)
Thickness (mm)
R410A
R22
* Use 1/2 H or H pipes.