English
11
•
Be sure to use both a spanner and torque wrench together, as shown
in the drawing, when connecting or disconnecting pipes to/from the
unit.
(Refer to Fig. 12)
•
Refer to “Table 1” for the dimensions of flare nut spaces.
•
When connecting the flare nut, coat the flare section (both inside and
outside) with ester oil or ether oil, rotate three or four times first, then
screw in.
(Refer to Fig. 13)
• Keep all the screw mounting resin parts (e.g., piping presser
plates) away from oil.
If oil adheres, the strength of the screw mounting resin parts may
drop.
CAUTION
•
Over-tightening may cause the flare nuts to crack or the refrigerant
to leak.
NOTE
•
Use the flare nut included with the unit main body.
Table 1
•
Refer to Table 1 to determine the proper tightening torque.
After the work is finished, make sure to check that there is no gas leak.
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT PIPING
“Do not use flux when brazing refrigerant piping. Therefore, use the phosphor copper brazing filler metal
(BCuP-2: JIS Z 3264/B-Cu93P-710/795: ISO 3677) which does not require flux.”
(Flux has extremely harmful influence on refrigerant piping systems. For instance, if the chlorine based flux is
used, it will cause pipe corrosion or, in particular, if the flux contains fluorine, it will damage the refrigerant oil.)
•
Before brazing local refrigerant piping, nitrogen gas shall be blown through the piping to expel air from the
piping.
If your brazing is done without nitrogen gas blowing, a large amount of oxide film develops inside the piping,
and could cause system malfunction.
•
When brazing the refrigerant piping, only begin brazing after having carried out nitrogen substitution or
while inserting nitrogen into the refrigerant piping. Once this is done, connect the indoor unit with a flared
or a flanged connection.
Pipe size
Tightening torque
(N·m)
Flare dimensions A (mm)
Flare
Ø6.4 (1/4”)
14.2 – 17.2
8.7 – 9.1
Ø9.5 (3/8”)
32.7 – 39.9
12.8 – 13.2
Ø12.7 (1/2”)
49.5 – 60.3
16.2 – 16.6
Ø15.9 (5/8”)
61.8 – 75.4
19.3 – 19.7
Torque wrench
Spanner
Piping union
Flare nut
Fig. 12
Fig. 13
Apply ester oil or
ether oil only inside
R0.4-0.8
A
90
0
±2
0
45
0
±2
0
4PEN494115-1A.book Page 11 Tuesday, October 3, 2017 10:51 AM