Haier AH1-070B Manual page 23

<Table-2>
Pipe size Tightening angle
Ø6.35 60°~90°
Ø9.52 60°~90°
Ø12.7 30°~60°
Ø15.88 30°~60°
Ø19.05 20°~35°
<Note>
• Excessive tightening will result in cracking at the flare 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.3). Finally use the flare or flange to connect the indoor unit and connection
kit.
(*1) Nitrogen replacement method is provided in the multi-split system work manual.
(*2) If nitrogen flowing 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.
<Note>
• For pipe welding, do not use antioxidant, for its residue may cause tube blocking and component fault.
• For pipe welding, do not use flux. If the flux is chlorine product, it will corrode the tube; if it contains fluorine, it will
even cause detrimental effects to the refrigerant system, such as refrigerant oil deterioration. Please do not use
phosphor copper for welding material (BCup-2).
Selection of piping dimensions
Select refrigerant branching dimensions between outdoor units and connection kit, between connection kit and
indoor units according to the Operation & Installation Manual of outdoor units and indoor units.
Dimensions (mm) of connection pipe of the vale box
model
AH1-070B
AH1-140B
AH1-280B
AH1-560B
AH1-730B
Recommended tool length
(mm)
150
200
250
300
450
Weld
Nitrogen
Refrigerant pipe
Dimension (outer diameter)
Liquid pipe / convertible dimension
Ø6.35/Ø9.52
Ø12.7/Ø15.88
Nitrogen cylinder
Binding
21
Apply refrigerant oil