Fujitsu AUYG18LVLB Design & Technical Manual page 187

2. Pipe design
2-1. Important items when using refrigerant (R410A)
• Refrigerant piping material and wall thickness
It is necessary to use seamless copper tubes for refrigerant use. Thickness of tubes are shown in
table below.
Nominal diameter
Outside diameter
Material
3
Wall thickness*
*1: Allowable tensile stress ≥ 33 N/mm
*2: Allowable tensile stress ≥ 61 N/mm
*3: Endurance pressure of the pipes: 4.2 MPa
Select the pipe size in accordance with local rules.
• Lubricant
Refrigerant
Lubricant
• Tools
R410A work requires a number of special tools. Since the tools (with * symbol) for R22 work can-
not be used for R410A, prepare them beforehand.
Tool name
Pipe cutter
Flaring tool*
Torque wrench*
Expander
Pipe bender
Nitrogen gas
Welder
Gauge manifold*
Charging hose*
Vacuum pump (with adapter)*
Electronic scale for refrigerant
charging
Gas leak tester*
*: For details, refer to the service manual.
2-1. Important items when using refrigerant (R410A)
in 1/4 3/8
mm 6.35 9.52
JIS H3300 C1220T-O or equivalent*
mm 0.8
2
2
Pipe cutting
Pipe flaring work
Flare nut connection
Expansion at pipe connection
Pipe bending work
Pipe interior oxidation prevention
Pipe brazing
Vacuum evacuation and
refrigerant charging operation
check
Gas leakage test
- 179 -
1/2 5/8 3/4
12.70 15.88 19.05
1
1.0 1.2
R410A (Mixed refrigerant)
Synthetic oil
Process and application
Refrigerant piping work
Air tightness test
Air tightness test ~ Refrigerant
additional charging
Vacuum drying
Refrigerant additional charging
7/8 1-1/8
22.22 28.58
JIS H3300 C1220T-H
2
or equivalent*
1.0
2. Pipe design