4. Refrigerant
Piping
Work
◆
The design pressure for this product is 601 psi (4.15MPa). The pressure required for refrigerant R410A is
1.4 times higher than that of the refrigerant R22. That means that the refrigerant piping for R410A must be
thicker than that for R22. Make sure to use specified refrigerant piping. Otherwise, the refrigerant piping
may rupture due to an excessive refrigerant pressure. Pay close attention to the piping thickness when
using copper refrigerant piping.
◆
Ensure that the stop valves are closed before removing the flare nut of the stop valves.
When handling the refrigerant, be sure to wear leather gloves to prevent injuries.
4.1 Precaution for Refrigerant Piping
(1) Use the copper pipe for refrigerant piping.
(2) Keep the copper pipes clean. Make sure there is no dust or moisture inside the pipes. Blow nitrogen or
dry, compressed air into the pipes to remove any dust or foreign materials before connecting them. Do not use
any cutting tools such as a grinder or saw which could produce metal particles.
(3) Take special care to prevent pollution or moisture settling from going into the interior pipe during piping
work.
(4) Avoid performing the piping connection work for outdoor unit in the rain.
(5) Refrigerant pipe ends
(6) Piping Thickness and Material
The thickness of refrigerant pipe differs depending on design pressure. For copper tube, pay attention to
pipe selection, because the piping thickness differs depending on its material.
NOTE:
Do not use the pipe
whose
allowable pressure is less than 4.15MPa.
The reference value of the refrigerant piping thickness is indicated in the table above.
Do not use the pipe which is considerably different from the reference value.
Diameter
(Φd)
R410A
Thickness
Temper
6.35 mm
0.8 mm
O
9.52 mm
0.8 mm
O
12.7 mm
0.8 mm
O
15.88 mm
1.0 mm
O
19.05 mm
1.0 mm
1/2H
22.2 mm
1.2 mm
1/2H
25.4 mm
1.2 mm
1/2H
17
