Daikin FHQ18PVJU Installation Manual page 8

Table 3
Pipe size
Further tightening angle
(in.)
φ3/8
60 to 90 degrees
φ5/8
30 to 60 degrees
After the work is fi nished, make sure to check that there
is no gas leak.
6-3 BRAZING REFRIGERANT PIPING
DANGER
CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT
PIPING
"Do not use fl ux when brazing refrigerant pipe. Therefore, use
the phosphor copper brazing fi ller metal (BCuP) which does not
require fl ux."
(Flux has an extremely negative effect on refrigerant piping sys-
tems. For instance, if chlorine based fl ux is used, it will cause
pipe corrosion. If the fl ux contains fl uorine, it will damage the
refrigerant oil.)
• Before brazing local refrigerant pipe, nitrogen gas shall be
blown through the pipe to expel air from the pipe.
If you brazing is done without nitrogen gas blowing, a large
amount of oxide fi lm develops inside the pipe, and could
cause system malfunction.
• When brazing the refrigerant pipe, only begin brazing after
having carried out nitrogen substitution or while inserting
nitrogen into the refrigerant pipe. Once this is done, connect
the indoor unit with a fl ared or a fl anged connection.
• Nitrogen should be set to 2.9 psi with a pressure-reducing
valve if brazing while inserting nitrogen into the pipe.
(Refer to Fig. 15)
Refrigerant pipe
Part to be
brazed
Nitrogen
Fig. 15
DANGER
• Use of oxygen may cause an explosion resulting in serious
injury or death. Only use nitrogen gas.
CAUTION
• Be sure to insulate any fi eld piping all the way to the piping
connection inside the unit. Any exposed piping may cause
condensate or a burn if touched.
6-4 PIPING INSULATION
• Make absolutely sure to execute thermal insulation works on
the pipe-connecting section after checking gas leakage by
thoroughly studying the following fi gure and using the insula-
tion pipe cover (6) and (7). (Fasten both ends with the clamps
(4).) (Refer to Fig. 16)
• Wrap the small sealing pad (9) only around the insulation for
the joints on the gas piping side. (Refer to Fig. 16)
8
Recommended arm length of tool
(in.)
Approx. 7 7/8
Approx. 11 13/16
Pressure-reducing
valve
Taping
hands valve
Nitrogen
Procedure for thermal insulation of gas-side pipe
Insulation pipe cover
for gas pipe (6)
Flare nut connection
Insulation pipe
cover (main unit)
Orient so that the end of
the wrapped insulation
pipe cover is facing up
Insulation pipe cover
(Locally procured)
Insulation pipe cover for gas pipe (6)
Gas pipe
Liquid pipe
Insulation pipe cover for liquid pipe (7)
Clamp (4) (× 4)
Procedure for thermal insulation of liquid-side pipe
Insulation pipe cover for
liquid pipe (7)
Flare nut connection
Orient so that the end of
the wrapped insulation
material is facing up
Insulation pipe cover
(Locally procured)
Fig. 16
(1) For piping facing back.
Remove the rear metal plate for pipe. (Refer to Fig. 17)
• The fi gure of the direction of back shows when both the pip-
ing and drain pipe are set backward.
When setting the piping to face up or right, attach the rear
metal plate for refrigerant pipe and plug a hole for drain pipe.
(See "4 PREPARATIONS BEFORE INSTALLATION" (3-3) on
page 6)
(2) For piping facing up.
• When setting the piping to face up, the L-shaped branch
pipe kit sold separately is required.
• Removing the top penetration lid and use the L-shaped branch
pipe kit sold separately to set the pipe. (Refer to Fig. 18, 19)
(3) For piping facing right.
• Cut out a slit hole on the decoration panel (right) and set the
pipe. (Refer to Fig. 17)
Right-facing
refrigerant
piping
Decoration panel (right) removable part
If only setting the drain pipe to
face right, cut this section only.
Wind around the
pipe, beginning at
the base.
Small sealing
pad (9)
Attach to base
Main unit
Clamp (4)
Attach to the bottom
(For both gas pipe and liquid pipe)
Insulation pipe cover (main unit)
Attach to base
Main unit
Clamp (4)
Rear-facing
refrigerant pipe
Rear right-facing
drain pipe
Right-facing drain pipe
Fig. 17
English