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<Caution items>
1) The opposite side dimension of the air-conditioner’s flared nut using R32 and the shape of the charge
port are the same as those of R410A.
2) Be careful not to charge refrigerant by mistake. Should the different type of refrigerant be mixed, be sure
to recharge the refrigerant.
3) Do not mix the other refrigerant or refrigerating oil with the refrigerant.
4) Since the pressure of R32 is 1.6 times higher than that of the former refrigerant (R22), use tools and
parts for high pressure resistance specification similar to R410A.
5) In the installation time, use clean pipe materials and work with great attention so that water and others do
not mix in because pipes are affected by impurities such as water, oxide film, oil, etc. Use the clean pipes.
Be sure to braze while flowing nitrogen gas in the pipe. (Never use gas other than nitrogen gas.)
6) For the earth protection, use a vacuum pump for air purge.
7) R32 refrigerant is Single-component refrigerant that does not change its composition.
Although it is possible to charge the refrigerant with either liquid or gas, charge it with liquid.
3. Pipe Materials
For the refrigerant pipes, copper pipe and joints are mainly used.
It is necessary to select the most appropriate pipes to conform to the standard.
Use clean pipes or joints to which little impurities adhere.
Be sure to select the pipes with copper thickness in the table below since the pressure of an air
conditioner using R32 is higher than that of R22.
2) Joint
The flare joint and socket joint are used for joints of the copper pipe.
The joints are rarely used for installation of the air conditioner.
However clear impurities when using them.
<Piping>
The pipe thickness, flare-finishing size, flare nut and others differ according to a refrigerant type.
When using a long copper pipe for R32, it is recommended to select “Copper or copper-base pipe without
seam” and one with bonded oil amount 40mg/10m or less.
Also do not use crushed, deformed, discolored (especially inside) pipes.
(Impurities cause clogging of expansion valves and capillary tubes.)
<Flare nut>
Use the flare nuts which are attached to the air conditioner unit.
Nominal
diameter
Outer
diameter (mm)
Thickne
ss
(mm)
R410A or R32
1/2
3/8
1/2
5/8
M
a
ke
su
re not to
us
e
a
thin copper
pipe
su
ch
as
0.7 mm copper
thickne
ss
in the m
a
rket.
6.4
9.5
12.7
15.9
0.80
0.80
0.80
1.00
1) Copper pipe
