Airwell VVFA Series Service Manual page 27

Note:
1. When connecting the pipe and the outdoor, please pay attention to the outdoor pipe dimension.
2. When adjusting the diameter among pipes and among the units, please must execute at the branch pipe side.
3. When welding with hard solder, please must blow nitrogen. If not, a number of oxide will be produced and cause
heavy damage.Besides,to prevent water and dust into the pipe, please make the brim as outer roll.
Adhesive side
Heat insulation
• Gas pipe and liquid pipe should be heat insulated separately.
• The material for gas pipe should endure the high temperature
over 120°C.That for liquid pipe should be over 70°C.
• The material thickness should be over 10mm, when ambient
temp. is 30°C, and the relative humidity is over 80%, the
material thickness should be over 15mm.
• He material should cling the pipe closely without gap, then
be wrapped with adhesive tape. The connection wire can not
be put together with the heat insulation material and should
be far at least 20cm.
Fix the refrigerant pipe
• In operation, the pipe will vibrate and expand or shrink. If not being fixed, the refrigerant will focus on one part to
cause the broken pipe.
• To prevent the central stress, fix the pipe for every 2-3m.
Pipe installation
When doing the piping connection, please do the following:
• Please don't let the pipe and the parts in the unit collide each other.
• When connecting the pipes, close the valves fully.
• Protect the pipe end against and water, impurities (welding after being flatted, or being sealed with adhesive
tape).
• Bend the pipe as large semi-diameter as possible(over 4 times of the pipe diameter).
• The connection between outdoor liquid pipe and the distributing pipe is flared type. Please expand the pipe with
the special tool for R410A after installing the expanding nut. But if the projecting pipe length has been adjusted
with the copper pipe gauge, you can use the original tool to expand the pipe.
• Since the unit is with R410A, the expanding oil is ester oil, not the mineral oil.
• When doing the flare connection, please do the following: When connecting the expanding pipe, fasten the pipes
with double-spanner. The torque refers to the former info.
Expanding pipe: A(mm)
Pipe outer diameter
Prepare on field
A
(mm)
Ø6.35 9.1
Ø9.52 13.2
Ø12.7 16.6
Ø15.88 19.7
Seal the connection and wrap the
heat insulator with adhesive tape
Liquid pipe
Projecting length of pipe to be expanded:
B(mm)
Pipe outer diameter
(mm)
Ø6.35
Ø9.52
Ø12.7
Ø15.88
25
Cut off pipe with the cutter
Cut off at the middle
Connection wire
over 20cm
Adhesive tape
Gas pipe
Heat insulator
When it is hard pipe
Special tool The former
for R410A
0-0.5 1.0-1.5
tool