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PIPE DESIGN
1.
IMPORTANT ITEMS WHEN USING REFRIGERANT (R410A)
1-1.
R410A operates at higher pressure and has less solubility with mineral oil than traditional R22
refrigerant. Therefore, the lubricant and a part of pipe material are different. Some special tools
are necessary.
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. The design pressure is 4.2 MPa.
Nominal Diameter
(in)
1/4"
3/8"
1/2"
5/8"
3/4"
Outside Diameter
(mm)
6.35
9.52
12.70
15.88
19.05
Material
JIS H3300 C1220T-O or equivalent *1
Wall Thickness *2
(mm)
0.8
0.8
0.8
1.0
1.2
*1: Allowable tensile stress ≥ 33 (N/mm
2
)
*2: Design pressure 4.2MPa
Please select the pipe size in accordance with local rules.
LUBRICANT
Refrigerant
R410A (Mixed refrigerant)
Lubricant
Synthetic oil
TOOLS
R410A work requires a number of special tools. Since the tools (with *3 symbol) for R22 work
cannot be used for R410A, prepare them beforehand.
Tool name
Process and application
Pipe cutter
Pipe cutting
Refrigerant piping work
Flaring tool *3
Pipe flaring work
Torque wrench *3
Flare nut connection
Expander
Expansion at pipe connection
Pipe bender
Pipe bending work
Nitrogen gas
Pipe interior oxidation prevention
Air tightness test
Welder
Pipe brazing
Gauge manifold *3
Vacuum evacuation and refrigerant
charging Operation check
Air tightness test ~
Refrigerant additional charging
Charging hose *3
Vacuum pump (with adaptor) *3
Vacuum drying
Electronic scale for refrigerant charging
Refrigerant additional charging
Gas leak tester *3
Gas leakage test
*3: Please refer to a service manual for details.
