Haier MRV 5-RC VP1-112B Service Manual page 121

<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 valve box, between valve box and indoor units
according to the following connection examples 1 and 2 and Tables 5-7.
Connection example 1: Connect an indoor unit to the downstream of the valve box
Select from Table 2 according to the
capacity type of the indoor units
Connection example 2: with branching in the downstream of the valve box
Select pipe dimensions of the refrigerant branching suite and its components in the indoor
unit according to the specifications or technical data provided together with the outdoor unit.
Refrigerant branching suite
Indoor unit Indoor unit
( ) For dimensions of the pipes to the downstream of the valve box, see the table 3. Use the attached pipes for
connection in the way shown in Pipe connection according to the pipes dimensions and diameters for indoor unit
connection selected in Table 2.
<Table 5> Total capacity and pipe dimensions (mm) of the indoor units
Total capacity of the
indoor units
Suction gas
Q (kW)
Q<16.8 Ø15.88×1.0
16.8≤Q<22.4 Ø19.05×1.0
22.4≤Q<28.0 Ø22.22×1.2
Downstream
Gas pipe
Liquid pipe
Indoor unit
Downstream
Gas pipe
Liquid pipe
Indoor unit
Pipe dimensions (OD × minimum wall thickness)
Upstream
High pressure gas
pipe pipe
Ø12.7×1.0
Ø15.88×1.0
Ø19.05×1.0
Select from Table 1 according to
total capacities of the indoor units
connected in the downstream
Upstream
HP gas pipe
Suction gas pipe
Valve box
Liquid pipe
Select from Table 1 according to total capacities
of the indoor units connected in the downstream
HP gas pipe
Suction gas pipe
Valve box
Liquid pipe
Downstream
Liquid pipe Gas pipe
Ø15.88×1.0
Ø9.52×0.8 Ø19.05×1.0
Ø22.22×1.2
118
To outdoor unit or
refrigerant branching suite
Upstream
To outdoor unit or
refrigerant branching suite
Liquid pipe
Ø9.52×0.8