[1-2 Handling and Characteristics of Piping Materials, Refrigerant, and Refrigerant Oil ]
Handling and Characteristics of Piping Materials,
Refrigerant, and Refrigerant Oil
1. Copper pipe materials
The distinction between O-materials (Annealed) and 1/2H-materials (Drawn) is made based on the strength of the pipes them-
O-materials (Annealed) can easily be bent with hands.
1/2H-materials (Drawn) are considerably stronger than O-material (Annealed) at the same thickness.
2. Types of copper pipes
Maximum working pressure
3.45 MPa [500psi]
4.30 MPa [624psi]
3. Piping materials/Radial thickness
Use refrigerant pipes made of phosphorus deoxidized copper.
The operation pressure of the units that use R410A is higher than that of the units that use R22.
Use pipes that have at least the radial thickness specified in the chart below.
(Pipes with a radial thickness of 0.7 mm or less may not be used.)
Pipe size (mm[in])
The pipes in the system that uses the refrigerant currently on the market are made with O-material (Annealed), even if the
pipe diameter is less than ø19.05 (3/4"). For a system that uses R410A, use pipes that are made with 1/2H-material (Drawn)
unless the pipe diameter is at least ø19.05 (3/4") and the radial thickness is at least 1.2t.
The figures in the radial thickness column are based on the Japanese standards and provided only as a reference. Use pipes
that meet the local standards.
Do not use the existing piping!
Soft copper pipes (annealed copper pipes). They can easily be bent with hands.
Hard copper pipes (straight pipes). They are stronger than the O-material (Annealed)
at the same radial thickness.
R22, R407C etc.
Radial thickness (mm)
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