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10.2.3  Connecting the Refrigerant Piping 
1  Decide piping length and then cut by using pipe cutter. Remove burrs from cut edge. 
2  Make flare after inserting the flare nut (locate at valve) onto the copper pipe. 
3  Align center of pipe to valve and then tighten with torque wrench to the specified torque as stated in the table. 
 
 
 
 
 
 
 
Do not overtighten, overtightening may cause gas leakage 
 
Piping size  Torque 
6.35 mm (1/4”)  [18 N•m (1.8 kgf.m)] 
9.52 mm (3/8”)  [42 N•m (4.3 kgf.m)] 
12.7 mm (1/2”)  [55 N•m (5.6 kgf.m)] 
15.88 mm (5/8”)  [65 N•m (6.6 kgf.m)] 
19.05 mm (3/4”)  [100 N•m (10.2 kgf.m)] 
10.2.3.1  Flaring the pipe end 
1  Please cut using pipe cutter and then remove the burrs. 
2  Remove the burrs by using reamer. If burrs is not removed, gas leakage may be caused. Turn the piping end 
down to avoid the metal powder entering the pipe. 
3  Please make flare after inserting the flare nut onto the copper pipes. 
 
 
 
10.2.4  Evacuation of the Equipment 
WHEN INSTALLING AN AIR CONDITIONER, BE SURE TO EVACUATE THE AIR INSIDE THE INDOOR UNIT AND 
PIPES in the following procedure. 
 
 
 
1  Connect a charging hose with a push pin to the Low side of a charging set and the service port of the 3-way 
valve. 
o  Be sure to connect the end of the charging hose with the push pin to the service port. 
2  Connect the center hose of the charging set to a vacuum pump with check valve, or vacuum pump and 
vacuum pump adaptor. 
3  Turn on the power switch of the vacuum pump and make sure that the needle in the gauge moves from 
0 cmHg (0 MPa) to -76 cmHg (-0.1 MPa). Then evacuate the air approximately ten minutes. 
4  Close the Low side valve of the charging set and turn off the vacuum pump. Make sure that the needle in the 
gauge does not move after approximately five minutes. 
Note : BE SURE TO FOLLOW THIS PROCEDURE IN ORDER TO AVOID REFRIGERANT GAS LEAKAGE.