5
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Preparation
Installer and user reference guide
22
FXFQ20~125BVEB
VRV system air conditioner
4P561452-1B – 2021.07
5.3 Preparing refrigerant piping
5.3.1 Refrigerant piping requirements
INFORMATION
Also read the precautions and requirements in the
NOTICE
The refrigerant R410A requires strict cautions for keeping the system clean, dry and
tight.
▪
Clean and dry: foreign materials (including mineral oils or moisture) should be
prevented from getting mixed into the system.
▪
Tight: R410A does not contain any chlorine, does not destroy the ozone layer,
and does not reduce earth's protection against harmful ultraviolet radiation.
R410A can contribute to the greenhouse effect if it is released. Therefore pay
special attention to check the tightness of the installation.
NOTICE
The piping and other pressure-containing parts shall be suitable for refrigerant. Use
phosphoric acid deoxidised seamless copper for refrigerant.
▪
Foreign materials inside pipes (including oils for fabrication) must be
≤30 mg/10 m.
Refrigerant piping diameter
For piping connections of the indoor unit use the following piping diameters:
Class
Pipe outer diameter (mm)
Liquid pipe
Gas pipe
20~50
Ø6.4
Ø12.7
63~125
Ø9.5
Ø15.9
Refrigerant piping material
▪
Piping material:
Phosphoric acid deoxidised seamless copper.
▪
Flare connections:
Only use annealed material.
▪
Piping temper grade and thickness:
Outer diameter (Ø)
Temper grade
Thickness (t)
(a)
6.4 mm (1/4")
Annealed (O)
≥0.8 mm
t
Ø
9.5 mm (3/8")
12.7 mm (1/2")
15.9 mm (5/8")
(a)
Depending on the applicable legislation and the maximum working pressure of the unit
(see "PS High" on the unit name plate), larger piping thickness might be required.
