– 14 –
Table 6-2-1 Thicknesses of annealed copper pipes
(2) Joints
For copper pipes, flare joints or socket joints are
used. Prior to use, be sure to remove all con-
taminants.
a) Flare Joints
Flare joints used to connect the copper pipes
cannot be used for pipings whose outer
diameter exceeds 20 mm. In such a case,
socket joints can be used.
Sizes of flare pipe ends, flare joint ends and
flare nuts are as shown in Tables 6-2-3 to 6-
2-6 below.
b) Socket Joints
Socket joints are such that they are brazed
for connections, and used mainly for thick
pipings whose diameter is larger than 20 mm.
Thicknesses of socket joints are as shown in
Table 6-2-2.
Table 6-2-2 Minimum thicknesses of socket joints
6-2-2. Processing of Piping Materials
When performing the refrigerant piping installation,
care should be taken to ensure that water or dust
does not enter the pipe interior, that no other oil
other than lubricating oils used in the installed air
conditioner is used, and that refrigerant does not
leak. When using lubricating oils in the piping
processing, use such lubricating oils whose water
content has been removed. When stored, be sure to
seal the container with an airtight cap or any other
cover.
(1) Flare Processing Procedures and Precautions
a) Cutting the Pipe
By means of a pipe cutter, slowly cut the pipe
so that it is not deformed.
b) Removing Burrs and Chips
If the flared section has chips or burrs,
refrigerant leakage may occur. Carefully
remove all burrs and clean the cut surface
before installation.
Nominal diameter
1/4
3/8
1/2
5/8
Outer diameter (mm)
6.35
9.52
12.70
15.88
Thickness (mm)
R410A
R22
0.80
0.80
0.80
0.80
0.80
0.80
1.00
1.00
Nominal diameter
1/4
3/8
1/2
5/8
Reference outer diameter of
copper pipe jointed (mm)
6.35
9.52
12.70
15.88
Minimum joint thickness
(mm)
0.50
0.60
0.70
0.80
