Flare cutting dimensions
45˚± 2˚
90˚± 0.5˚
Flare nut tightening torque
ø
A
R1/64 to R1/32
(inch)
A
Liquid pipe
B
Gas pipe
C
Insulation
D
Taping
Fig. 4-5
5
4. Refrigerant piping work
4.3. Connecting pipes (Fig. 4-4, Fig. 4-5)
• Fasten flare nut with a torque wrench as specified in the table (refer to 4.2.).
• When fastened too tight, flare nut may eventually break and cause refrigerant
leakage.
[Fig. 4-5]
• Apply thin layer of refrigerant oil to pipe and joint seating surface before tightening
flare nut.
A
• Use wrenches to tighten piping connections.
B
• Use leak detector or soapy water to check for gas leaks after connections are
completed.
• Apply refrigerant oil over the entire flare seat surface.
C
• Use the flare nuts for the following pipe size.
D
KA09, KA12
KA15, KA18
Gas side
Pipe size inch (mm)
3/8 (9.52)
1/ (1.7)
Liquid side
Pipe size inch (mm)
1/4 (6.35)
1/4 (6.35)
*1: The flare nut is attached to its pipe.
*2: The flare nut is in the outdoor unit accessory.
Do not use the flare nuts other than the attachment. If it is used, a gas leakage
or even a pipe extraction may occur.
• Refrigerant pipe bending radius must be 4 in. (100 mm) or more.
• Make sure the pipes do not contact the compressor. Abnormal noise or vibration
may result.
1
Pipes must be connected starting from the indoor unit.
Flare nuts must be tightened with a torque wrench.
2
Flare the liquid pipes and gas pipes and apply a thin layer of refrigerant oil
(Applied on site).
Warning:
Be careful of flying flare nut. (Internally pressurized)
Remove the flare nuts as follows:
1. Loosen the nut until you hear a hissing noise.
2. Do not remove the nut until the gas has been completely released (i.e.,
hissing noise stops)
3. Check that the gas has been completely released, and then remove the nut.
A
(Fig. 4-5)
Pipe diameter
Flare dimensions
øA dimensions
inch
(mm)
inch
(mm)
1/4”
(6.35)
11/3 - 3/64
(8.7 - 9.1)
3/8”
(9.52)
1/ - 33/64
(1.8 - 13.)
1/”
(1.7)
41/64 - 1/3 (16. - 16.6)
5/8”
(15.88)
49/64 - 25/32 (19.3 - 19.7)
Fig. 4-4
4.4. Purging procedures and leak test
1) Remove service port cap of stop valve on the side of the outdoor unit gas pipe.
) Connect gauge manifold valve and vacuum pump to service port of stop valve
on the gas pipe side of the outdoor unit.
3) Run the vacuum pump 15 minutes or more.
4) Check the vacuum with the gauge manifold valve, then close it and shut off the
vacuum pump.
5) Leave as it is for one or two minutes. Make sure pointer gauge manifold valve
remains in the same position. Confirm that pressure gauge shows -0.101 MPa
[Gauge] (-30 in.Hg [-760 mmHg]).
6) Quickly remove gauge manifold valve from service port of stop valve.
7) After refrigerant pipes are connected and evacuated, fully open all stop valves
on both sides of gas pipe and liquid pipe. Operating the unit without fully opening
the valves lowers the performance and causes problems.
8) Refer to 4.1. Refrigerant pipe, and charge the prescribed amount of refrigerant if
needed. Be sure to charge slowly with liquid refrigerant. Otherwise, composition
of the refrigerant in the system may be changed and affect performance of the
air conditioner.
9) Tighten cap of service port.
10) Conduct a leak test
Stop valve for
GAS
Stop valve cap
(Torque 19.6 to
29.4 N•m, 200
Vacuum pump (or the vacuum
pump with the function to
Gauge manifold valve
(for R410A)
Compound pressure gauge
(for R410A)
–0.101 MPa
(–30 in.Hg
[–760 mmHg])
Handle
Low
Handle High
Adapter for pre-
venting the back
Charge hose
(for R410A)
*Close
*Open
Hexagonal wrench
Precautions when using the control valve When attaching the control valve
to the service port, valve core may
deform or loosen if excess pressure
is applied. This may cause gas leak.
Service port
Charge hose
Body
Close
Open
Control valve
A
When attaching the control valve to
the service port, make sure that the
valve core is in closed position, and
then tighten part A. Do not tighten
part A or turn the body when valve
core is in open position.
Service port cap
(Torque 13.7 to
17.7 N•m, 140 to
180 kgf•cm)
*4 to 5 turns
Stop valve
for LIQUID
Pressure gauge
(for R410A)
