25
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 atted, 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 ared 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 are connection, please do the following: When connecting the expanding pipe, fasten the pipes 
with double-spanner. The torque refers to the former info.
•  The outdoor gas pipe and the refrigerant distributing pipe, as well the refrigerant distributing pipe and the branch 
pipe should be welded with hard solder.
•  Weld the pipe at the same time charge the nitrogen. Or it will cause a number of impurity (a lm of oxidation) to 
clog the capillary and the expansion valve, further cause the deadly failure.
•  Protect the pipe end against the water, impurity into the pipes (welding after being at, or being sealed with 
adhesive tape).
•  The refrigerant pipe should be clean. The nitrogen should ow under the pressure of about 0.2Mpa and when 
charging the nitrogen, stop up the end of the pipe by hand to enhance the pressure in the pipe, then loose the 
hand (meanwhile stop up the other end).
•  When connecting the pipes, close the valves fully.
•  When welding the valve and the pipes, use  the wet cloth to cool down the valve and the pipes.
Pipe outer diameter
(mm)
 A 
Ø6.35 9.1
Ø9.52 13.2
Ø12.7 16.6
Ø15.88 19.7
Expanding pipe: A(mm)
Pipe outer 
diameter
(mm)
 When it is hard pipe 
Special tool 
for R410A
The former
tool
Ø6.35
0-0.5 1.0-1.5
Ø9.52
Ø12.7
Ø15.88
Projecting length of pipe to be expanded: B(mm)
Seal the pipe end with adhesive tape or the stopper to 
increase the resistance, ll up the pipe with nitrogen.
Only nitrogen gas 
can be used
Brazing
<N2>
Taping
Adhesive tape
Flat
Brazing
1st side
Hand
2nd side
Source valve
0.2MPa