13.2.2  Piping connection
1  Open the air inlet grille.
Press and slide the cover of the air inlet grille in the direction of 
the arrow with ngers in the holes on the cover.
Air inlet grille
Holes  
(2 or 3 portions)
Remove the supporting string from the side plate.
Side plate
Supporting 
string
While the air inlet grille is being opened, depress the knobs of 
hinge (), push the air inlet grille toward arrow direction () and 
remove the air inlet grille.
 Push
 Depress
Hinge
Depress the knob of 
hinge and push the air 
inlet grille forward.
2  Perform the aring work as shown below.
A
d
90
o 
+
 2
o
45
o
 
+
 2
o
mm (in.)
Diameter (Ød)
+0
A
-0.4
6.35 (1/4) 9.1
9.52 (3/8) 13.2
12.7 (1/2) 16.6
15.88 (5/8) 19.7
3  Use specic are nut.
4  Check that there are no scratch, chip, deformation, gap, etc. 
at the aring part.
5  Apply the refrigerant oil in a thin layer to the inside of the 
aring part of the pipe before tightening the are nut. And the 
are nut must be tightened using two spanners according 
to the tightening torque as shown in the gure below. The 
tightening work will be easier if tightening the are pipe in 
order of the liquid pipe, the gas pipe. Check the leakage of 
the refrigerant after the tightening work.
? NOTE
•  If the refrigerant oil attaches to the air panel, it may cause a crack. 
Pay attention not to attach.
•  Refrigerant  oil  is  eld-supplied:  [Ethereal  Oil  FVC50K,  FVC68D 
(Idemitsu Kousan Co. Ltd.)]
Do not apply the 
refrigerant oil to the 
outside of the aring 
part.
Apply refrigerant oil
Required tightening torque (JIS B8607)
Pipe size Tightening torque
Ø6.35 (1/4) 14 - 18 (Nm)
Ø9.52 (3/8) 34 - 42 (Nm)
Ø12.7 (1/2) 49 - 61 (Nm)
Ø15.88 (5/8) 68 - 82 (Nm)
! CAUTION
Tighten  the  are  nuts  according  to  the  specied  torque.  If  not,  it  may 
cause the refrigerant leakage.
REFRIGERANT PIPING WORK
PMML0551 rev.4 - 07/2023 - A10762310A
19
EN