Haier MRV5-H - Page 254

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<Table-2>
Pipe size OD
inch
.
(mm)
Tightening angle
Recommended tool length
inch
.
(mm)
1/4(6.35) 60°~90° 5.90(150)
3/8(9.52) 60°~90° 7.87(200)
1/2(12.7) 30°~60° 9.84(250)
5/8(15.88) 30°~60° 11.81(300)
3/4(19.05) 20°~35° 17.72(450)
7/8(22.22) 15°~30° 23.62(600)
Apply refrigerant oil
Fig.8
Fig.9
Ø19.05 pipe connected on site
Welding
Accessory pipe
Valve box
Ø19.05 pipe connected on site
Welding
Valve box
<Note>
• Excessive tightening will result in cracking at the are and refrigerant leakage.
• To weld the refrigerant pipe, please make nitrogen replacement (*1), or send nitrogen (*2) into the refrigerant pipe
while welding the pipe (refer to Fig.10). Finally use the are or ange to connect the indoor unit and valve box.
(*1) Nitrogen replacement method is provided in the multi-split system work manual.
(*2) If nitrogen owing and welding proceed simultaneously, do use pressure reducing valve. Approximately 0.02
MPa (0.2 Kg/cm with a slight feeling of breeze) pressure is quite proper.
Fig.10
Nitrogen cylinder
Refrigerant pipe
Nitrogen
Nitrogen
Weld
Binding
<Note>
• For pipe welding, do not use antioxidant, for its residue may cause tube blocking and component fault.
• For pipe welding, do not use ux. If the ux is chlorine product, it will corrode the tube; if it contains uorine, it will
even cause detrimental e󰀨ects to the refrigerant system, such as refrigerant oil deterioration. Please do not use
phosphor copper for welding material (BCup-2).