Daikin VRV system FXMQ250AXVMB - Piping Installation; Preparing Refrigerant Piping; Refrigerant Piping Requirements

17 | Piping installation
Installer and user reference guide
49
FXMQ-A
VRV system air conditioner
4P701548-1 – 2022.07
17 Piping installation
In this chapter
17.1 Preparing refrigerant piping ................................................................................................................................................... 49
17.1.1 Refrigerant piping requirements ........................................................................................................................... 49
17.1.2 Refrigerant piping insulation.................................................................................................................................. 50
17.2 Connecting the refrigerant piping.......................................................................................................................................... 50
17.2.1 About connecting the refrigerant piping............................................................................................................... 50
17.2.2 Precautions when connecting the refrigerant piping............................................................................................ 51
17.2.3 Guidelines when connecting the liquid piping ...................................................................................................... 52
17.2.4 Guidelines when connecting the gas piping.......................................................................................................... 53
17.2.5 To connect the refrigerant piping to the indoor unit............................................................................................ 54
17.1 Preparing refrigerant piping
17.1.1 Refrigerant piping requirements
NOTICE
The piping and other pressure-containing parts shall be suitable for refrigerant. Use
phosphoric acid deoxidised seamless copper for refrigerant piping.
INFORMATION
Also read the precautions and requirements in the "2 General safety
precautions"[46].
▪ Foreign materials inside pipes (including oils for fabrication) must be
≤30mg/10m.
Refrigerant piping diameter
Use the same diameters as the connections on the outdoor units:
Pipe outer diameter (mm)
Class Liquid pipe Gas pipe
200 Ø9.5mm Ø19.1mm
250 Ø9.5mm Ø22.2mm
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)
9.5mm (3/8") Annealed (O) ≥0.8mm
t
Ø
19.1mm (3/4")
22.2mm (7/8")
(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.