18
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Piping installation
Installer and user reference guide
64
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452191-1B – 2020.10
18.1 Preparing refrigerant piping
18.1.1 Refrigerant piping requirements
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.
▪
Temper grade: use piping with temper grade in function of the pipe diameter as
listed in table below.
Pipe Ø
Temper grade of piping material
≤15.9 mm
O (annealed)
≥19.1 mm
1/2H (half hard)
▪
All piping lengths and distances have been taken into consideration (see
"18.1.5 About the piping length"
▪
The pipe thickness of the refrigerant piping shall comply with the applicable
legislation. The minimal pipe thickness for R410A piping must be in accordance
with the table below.
Pipe Ø
Minimal thickness t
6.4 mm/9.5 mm/12.7 mm
0.80 mm
15.9 mm
0.99 mm
19.1 mm/22.2 mm
0.80 mm
28.6 mm
0.99 mm
34.9 mm
1.21 mm
41.3 mm
1.43 mm
▪
In case the required pipe sizes (inch sizes) are not available, it is also allowed to
use other diameters (mm sizes), taken the following into account:
-
Select the pipe size nearest to the required size.
-
Use the suitable adapters for the change-over from inch to mm pipes (field
supply).
-
The additional refrigerant calculation has to be adjusted as mentioned in
"18.5.3 To determine the additional refrigerant amount"
96].
