Daikin VRV II Series - Page 27

Si39-303 Installation
General Information 21
(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 31)
 Close the main valve on the nitrogen cylinder.
 Repeat the above operation for unit B.
 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
!
The piping used must meet the requirements of the JIS standard or equivalent. (Size, material,
thickness, etc.)
Specification: Oxidized phosphorous seamless copper pipe
!
Long pipe lengths or coiled pipe (copper pipe with heat insulation coating) should be used to avoid the
necessity for frequent brazing.
(* Make sure the thickness and material shall be selected in accordance with following table.)
!
Size of Refrigerant Piping
*The thickness and material shall be selected in accordance with local code.
b) Brazed joints and special branches
1. General use (L bend joint, socket joint, T joint, etc.)
!
Joints must meet the requirements of the relevant JIS standard. (Size, materials, thickness, etc.)
2. Special branches
!
The Daikin outdoor unit multi connection kit, REFNET joint, REFNET header or Reducing socket should
be used.
Example: R410A RXYQ-M Series
Refer detail of DAIKIN REFNET joint and REFNET header on page 126.
Outside Diameter (mm) Material
φ
6.4 0
φ
9.5 0
φ
12.7 0
φ
15.9 0
φ
19.1 1/2H
φ
22.2 1/2H
φ
25.4 1/2H
φ
28.6 1/2H
φ
31.8 1/2H
φ
34.9 1/2H
φ
38.1 1/2H
φ
41.3 1/2H