227
3. Piping Design
SYSTEM DESIGN
S.D. WR2
MEE15K036
3. Piping Design
3-1. R410A Piping material
Refrigerant pipe for CITY MULTI shall be made of phosphorus deoxidized copper, and has two types.
A. Type-O: Soft copper pipe (annealed copper pipe), can be easily bent with human's hand.
B. Type-1/2H pipe: Hard copper pipe (Straight pipe), being stronger than Type-O pipe of the same radical thickness.
The maximum operation pressure of R410A air conditioner is 4.30 MPa [623psi]. The refrigerant piping should ensure the safety
under the maximum operation pressure. MITSUBISHI ELECTRIC recommends pipe size as Table 3-1, or You shall follow the local
industrial standard. Pipes of radical thickness 0.7mm or less shall not be used.
* For pipe sized ø19.05 (3/4") for R410A air conditioner, choice of pipe type is up to you.
* The figures in the radial thickness column are based on the Japanese standards and provided only as a reference. Use pipes that meet the
local standards.
Size (mm)
Size (inch) Radial thickness (mm)
Pipe type
ø6.35
ø1/4"
0.8
Type-O
ø9.52
ø3/8"
0.8
Type-O
ø12.7
ø1/2"
0.8
Type-O
ø15.88
ø5/8"
1.0
Type-O
ø19.05
ø3/4"
1.2
Type-O
ø19.05
ø3/4"
1.0
Type-1/2H or H
ø22.2
ø7/8"
1.0
Type-1/2H or H
ø25.4
ø1"
1.0
Type-1/2H or H
ø28.58
ø1-1/8"
1.0
Type-1/2H or H
ø31.75
ø1-1/4"
1.1
Type-1/2H or H
ø34.93
ø1-3/8"
1.2
Type-1/2H or H
ø41.28
ø1-5/8"
1.4
Radial thickness (mil)
[32]
[32]
[32]
[40]
[48]
[40]
[40]
[40]
[40]
[44]
[48]
[56]
Type-1/2H or H
Table 3-1. Copper pipe size and radial thickness for R410A CITY MULTI.
Flare
Due to the relative higher operation pressure of R410A compared to R22, the flare connection should follow dimensions
mentioned below so as to achieve enough the air-tightness.
Flare pipe
Pipe size
A (For R410A)
Flare nut
Pipe size
(mm[in.])
(mm[in.])
B (For R410A)
ø6.35 [1/4"]
ø9.52 [3/8"]
ø12.70 [1/2"]
ø15.88 [5/8"]
ø19.05 [3/4"]
24.0
16.6
19.7
9.1
13.2
ø6.35 [1/4"]
ø9.52 [3/8"]
ø12.70 [1/2"]
ø15.88 [5/8"]
ø19.05 [3/4"]
36.0
17.0
22.0
26.0
29.0
A
B
0000003813.BOOK 227 ページ ２０１５年１１月１１日 水曜日 午後４時４分
