Installation
SiEN34-705
26
General Information
(The nature and amount of the extraneous material inside the pipe can be checked during
flushing by placing a rag lightly over the end of the pipe. In the unlikely case that even a small
quantity of moisture is found then the inside of the pipe should be dried out thoroughly.)
Action:
1. Flush the inside of the pipe with nitrogen gas. (Until such time as the moisture disappears.)
2. Carry out a thorough vacuum drying operation. (See page 39)
1
Close the main valve on the nitrogen cylinder.
2
Repeat the above operation for unit B.
3
When the liquid pipe operations have been completed then do the same with the gas
pipes.
Choice of
Materials for
Refrigerant
Piping
a) Refrigerant piping
Selection of piping material
1. Foreign materials inside pipes (including oils for fabrication) must be 30mg/10m or less.
2. Use the following material specification for refrigerant pipping:
• construction material: Phosphoric acid deoxidized seamless copper for refrigerant.
• size: Determine the proper size referring to chapter “Example of connection”.
• The wall thickness of the refrigerant piping should comply with relevant local and national
regulations.
For R-410A the design pressure is 4.0 MPa.(40.8kgf/cm
2
).
3. Make sure to use the particular branches of piping that have been selected referring to
chapter “Example of connection”.
4. The piping minimum thickness and material.
* The min. thickness of the pipes shows the requirements of Japanese High Pressure Gas Control
low. (As of Jan. 2003)
And the temper grade (
#
, 1/2H) shows the material type of JIS H 3300.
The thickness and material should comply with relevant local and national regulations for
the design pressure 4.0MPa (40bar).
Select the wall thickness in accordance with relevant local and national regulations.
R-410A
Size
Temper grade Minimum thickness (mm)
φ
6.4
#
0.80
φ
9.5
#
0.80
φ
12.7
#
0.80
φ
15.9
#
0.99
φ
19.1
1/2H
0.80
φ
22.2
1/2H
0.80
φ
25.4
1/2H
0.88
φ
28.6
1/2H
0.99
φ
31.8
1/2H
1.10
φ
34.9
1/2H
1.21
φ
38.1
1/2H
1.32
φ
41.3
1/2H
1.43
