Toshiba RAV-SP181BT-UL Installation Manual Download Page 13

Page: 13 / 26

– 12 –

Refrigerant piping and evacuation



Refrigerant piping

1. Use the following items for the refrigerant

piping.
Material: Seamless phosphorous deoxidized
copper pipe.
Wall thickness: 0.03" (0.8 mm) or more 1/2"

(12.7 mm)
(C1220T-0)
0.04" (1.0 mm) or more for 1-1/8"
(28.6 mm)
(C1220T-1/2H).

Do not use any copper pipes with a wall
thickness less than these thicknesses.

2. Flare nut and flare works are also different from

those of the conventional refrigerant.
Take out the flare nut attached to the main unit of the
air conditioner, and use it.

REQUIREMENT

When the refrigerant pipe is long, provide support
brackets at intervals of 8’2” - 9’10” (2.5 - 3 m) to clamp
the refrigerant pipe. Otherwise, abnormal sound may
be generated.

CAUTION

IMPORTANT 4 POINTS FOR PIPING WORK

1. Remove dust and moisture from the inside of the

connecting pipes.

2. Tight connection (between pipes and unit)
3. Evacuate the air in the connecting pipes using

VACUUM PUMP.

4. Check the gas leakage. (Connected points)



Permissible piping length and
height difference

They vary according to the outdoor unit.
For details, refer to the Installation Manual attached to
the outdoor unit.



Pipe size

Flaring

• Cut the pipe with a pipe cutter.

Remove burrs completely.
Remaining burrs may cause gas leakage.

• Insert a flare nut into the pipe, and flare the pipe.

As the flaring sizes of R410A differ from those of
refrigerant R22, the flare tools newly manufactured
for R410A are recommended.
However, the conventional
tools can be used by adjusting
projection margin of the
copper pipe.

▼

Projection margin in
flaring : B (Unit : in (mm))

Rigid (Clutch type)

▼

Flaring dia. meter size : A (Unit : in (mm))

* In case of flaring for R410A with the

conventional flare tool, pull it out approx.

0.02" (0.5 mm) more than that for R22 to

adjust to the specified flare size.

The copper pipe gauge is useful for

adjusting projection margin size.

Model

name

RAV-

SP18 type

SP24, SP30,

SP36, SP42

type

Pipe size

Gas side

1/2"

(12.7 mm)

5/8"

(15.9 mm)

Liquid side

1/4"

(6.4 mm)

3/8"

(9.5 mm)

Outer dia. of copper

pipe

R410A tool

used

Conventional

tool used

R410A

1/4” (6.4), 3/8” (9.5)

0 - 0.02”

(0 - 0.5)

0.04” - 0.06”

(1.0 to 1.5)

1/2” (12.7), 5/8” (15.9)

Outer dia. of copper

pipe

–0.02” (-0.4)

R410A

1/4” (6.4)

0.36” (9.1)

3/8” (9.5)

0.52” (13.2)

1/2” (12.7)

0.65” (16.6)

5/8” (15.9)

0.78” (19.7)

Tightening connection

CAUTION

• Do not apply excessive torque. Otherwise, the nut

may crack depending on the conditions.

▼

Tightening torque of flare pipe connections

Pressure of R410A is higher than that of R22.
(Approx. 1.6 times)
Therefore, using a torque
wrench, tighten the flare pipe
connecting sections which
connect the indoor and
outdoor units of the specified
tightening torque.
Incorrect connections may
cause not only a gas leak, but
also a trouble of the
refrigeration cycle.
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers. Then
tighten the nut with a spanner and torque wrench as
shown in the figure.

REQUIREMENT

Tightening with an excessive torque may crack the nut
depending on installation conditions.
Tighten the nut within the specified tightening torque.

Piping with outdoor unit

• Shape of valve differs according to the outdoor unit.

For details of installation, refer to the Installation
Manual of the outdoor unit.



Evacuation

Using a vacuum pump, perform vacuuming from the
charge port of valve of the outdoor unit.
For details, follow to the Installation Manual attached to
the outdoor unit.
• Never use the refrigerant sealed in the outdoor unit

for air purge.

REQUIREMENT

For the tools such as charge hose, etc., use those
manufactured exclusively for R410A.

Refrigerant amount to be added

For addition of the refrigerant, add refrigerant “R410A”
referring to the attached Installation Manual of outdoor
unit.
Be sure to use a scale to charge the refrigerant of
specified amount.

REQUIREMENT

• Charging an excessive or too little amount of

refrigerant causes a trouble of the compressor.
Be sure to charge the refrigerant of specified
amount.

• A personnel who charged the refrigerant should

write down the pipe length and the added
refrigerant amount in the nameplate attached to the
service panel of the outdoor unit. It is necessary to
troubleshoot the compressor and refrigeration cycle
malfunction.

Open the valve fully

Open the valve of the outdoor unit fully. A 4 mm
hexagonal wrench is required for opening the valve.
For details, refer to the Installation Manual attached to
the outdoor unit.

Gas leak check

Check with a leak detector or soap water whether gas
leaks or not, from the pipe connecting section or cap of
the valve.

REQUIREMENT

Use a leak detector manufactured exclusively for HFC
refrigerant (R410A, R134a, etc.).

Unit : ft•lbs (N•m)

Outer dia. of copper pipe

Tightening torque

1/4" (6.4 mm)

10 - 13 (14 - 18)

3/8" (9.5 mm)

24 - 31 (33 - 42)

1/2" (12.7 mm)