Hitachi RAS-8FSNM - 5 Refrigerant Piping Work; Piping Materials

10
5. Refrigerant Piping Work
Use refrigerant R410A in the refrigerant cycle.
Do not charge oxygen, acetylene or other
flammable and poisonous gases into the
refrigerant cycle when performing a leakage
test or an air-tight test. These types of gases
are extremely dangerous and can cause an
explosion. It is recommended that
compressed air, nitrogen or refrigerant be
used for these types of tests.
5.1 Piping Materials
(1) Prepare locally-supplied copper pipes.
(2) Select the piping size from the Table 5.1.
(3) Select clean copper pipes. Make sure
there is no dust and moisture inside of the
pipes. Blow the inside of the pipes with
nitrogen or dry air, to remove any dust or
foreign materials before connecting pipes.
l Cap the end of the pipe when the pipe is to
be inserted through a hole.
l Do not put pipes on the ground directly
without a cap or vinyl tape at the end of the
pipe.
NOTE
l Cautions for Refrigerant Pipe Ends
When installing pipe through
the wall, secure a cap at the
end of the pipe.
Correct
CorrectIncorrect Incorrect
Correct Incorrect
HoleHole
Attach a cap
or vinyl tape.
Attach a cap
or vinyl tape.
Attach a cap
or vinyl bag with
rubber band.
Do not place the pipe
directly on the ground.
Rain water can
enter.
B
Flare Nut
l Flaring Dimension
Perform the flaring work as shown below.
l Piping Thickness and Material
Use the pipe as below.
l Flare Nut Dimension
Use the flare nut as below.
Material is based on a JIS standard (JIS B8607).
(T) It is impossible to perform the flaring
work with 1/2H material. In this case,
use an accessory pipe (with a flare).
0.4 ~ 0.8R
A
d
90
o
+
2
o
45
o
+
2
o
(mm)
+0
-0.4
R410A
6.35 9.1
9.53 13.2
12.7 16.6
15.88 19.7
19.05 (T)
Diameter
d
A
(mm)
R410A
Thickness Material
6.35
0.8 O material
9.53
0.8 O material
12.7
0.8 O material
15.88
1.0 O material
19.05
1.0 1/2H material
22.2
1.0 1/2H material
25.4
1.0 1/2H material
28.6
1.0 1/2H material
Diameter
<Flare Nut Dimension B (mm)
Diameter R410A
6.35
17
9.53
22
12.7
26
15.88
29
19.05
36
Dimension is based on a JIS standard
(JIS B8607).