Selection Of The Copper Pipes; Three Principles On Work With Refrigerant Pipes - Hitachi UTOPIA R32 Series Installation And Operation Manual

5.1 Selection of the copper pipes

The copper pipe used for the installation must be specific for refrigeration systems.
!
CAUTION
• The copper pipe used in the refrigeration installations is different to the copper pipe used in
installations carrying domestic or heating water.
• The copper pipe for refrigeration installations is especially treated for outdoors and indoors. The
interior surface finish makes it easier for the refrigerant to circulate and withstands the action of
the lubricant oil used in outdoor units.
Select the pipe with the appropriate diameter and thickness. Use the table below to select the
most appropriate pipe:
Nominal diameter
mm
Ø6.35
Ø9.52
Ø12.7
Ø15.88
Ø19.05
Ø22.2
Ø25.4
Ø28.58
Ø31.75
Ø38.1
Ø41.3
Ø44.45
Ø50.8
Always use clean copper pipes with no signs of knocks or cracks. Make sure there is no dust or
dampness on the inside. A system with no moisture or oil contamination will give maximum
performance and life cycle compared to that of a poorly prepared system.

5.2 Three principles on work with refrigerant pipes

The basic refrigerant pipe installation work must be carried out paying particular attention to avoid
the infiltration of humidity or dust while working with the refrigerant piping. Otherwise, rust may
appear inside the system or the units and cause serious faults.
PMEN0654 rev.0 - 12/2023
Thickness (mm)
Inches
1/4 0.80
3/8 0.80
1/2 0.80
5/8 1.00
3/4 1.00
7/8 1.00
1 1.00
1-1/8 1.00
1-1/4 1.10
1-1/2 1.35
1-5/8 1.45
1-3/4 1.55
2 1.78
Supply
Coil
Coil
Coil
Coil
Straight lengths
Straight lengths
Straight lengths
Straight lengths
Straight lengths
Straight lengths
Straight lengths
Straight lengths
Straight lengths
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