Table of Contents
SiEN34-705
2.6
Refrigerant Piping
Note:
! All field piping must be installed by a licensed refrigeration technician and must comply with
! After piping work is complete, do not under any circumstances open the shutoff valve until
! Do not use flux when brazing the refrigerant piping. Use the phosphor copper brazing filler
2.6.1 Selection of Piping Material and Refrigerant Branching Kit
! Use only pipes which are clean inside and outside and which do not accumulate harmful
! Use the following items for the refrigerant piping.
outer diameter
smallest thickness
outer diameter
smallest thickness
! For piping work, follow the maximum tolerated length, difference in height, and length after a
! A refrigerant branching kit (sold separately) is needed for piping branches and connection of
2.6.2 Protection Against Contamination when Installing Pipes
Protect the piping to prevent moisture, dirt, dust, etc. from entering the piping.
Outdoor
Indoor
Note:
Exercise special caution to prevent dirt or dust when passing piping through holes in walls and
when passing pipe edges to the exterior.
Installation Manual
relevant local and national regulations.
"2-7. Field Wiring" and "2-10. Checking of Device and Installation Conditions" are complete.
metal (BCuP-2: JIS Z 3264/B-Cu93P-710/795: ISO 3677) which does not require flux.
(Flux has extremely harmful influence on refrigerant piping systems. For instance, if the
chlorine based flux is used, it will cause pipe corrosion or, in particular, if the flux contains
fluorine, it will damage the refrigerant oil.)
sulfur, oxidants, dirt, cutting oils, moisture, or other contamination. (Foreign materials inside
pipes including oils for fabrication must be 30mg/10m or less.)
Material: Jointless phosphor-deoxidized copper pipe
Size: See "2-6-5 Example of connection" to determine the correct size.
Thickness: Select a thickness for the refrigerant piping which complies with national and
local laws.
For R-410A, the design pressure is 4.0 MPa (40-bar).
The minimum thickness of piping according to Japan's High-Pressure Gas Safety Law (as of
January 2003) is shown below.
Temper grade (O type, 1/2H type) in the table indicate the material types specified in JIS H
3300.
Temper grade
φ6.4
0.80
Temper grade
φ19.1
0.80
branch indicated in the "2-6-5 Example of connection".
piping between outdoor unit (in case of multi system).
Use only separately sold items selected specifically according to the refrigerant branch kit
selection in the "2-6-5 Example of connection".
Place
More than a month
Less than a month
Regardless of the period
(unit: mm)
O type
φ9.5
φ12.7
φ15.9
0.80
0.80
0.99
1/2H type
φ22.2
φ25.4
φ28.6
0.80
0.88
0.99
Installation period
Heat Pump 60Hz (RXYQ5~54P)
φ31.8
φ34.9
φ38.1
1.10
1.21
1.32
Protection method
Pinch the pipe
Pinch or tape the pipe
(unit: mm)
φ41.3
1.43
273
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