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61 

Copper pipes are used for refrigerant piping. Pipes 
which comply with JIS Regulations need to be used. 
Room air conditioners which use R410A and R32 
have higher pressure; thus, using pipes which comply 
with the Regulations is important. 
The pipe thickness is regulated by revised JIS B 8607 
“Flaring and brazing fittings for refrigerant” and the 
pipe thickness for R410A, R32 is shown in the table. 
 
 
 

Pipe thickness 
 

O and OL materials 

Thickness (mm) 

Diameter 

Diameter 

(mm) 

R410A 

R32 

R22 

1/4 6.35 

0.80 

3/8 9.52 

0.80 

1/2 12.70 

0.80 

5/8 15.88 

1.00 

 

  For connection piping, use copper phosphate seamless pipes (1220T) as regulated in “JIS H 3300” and the pipe 

thickness is 0.8 mm. 

  In the market, there are some pipes of 0.7 mm thickness, but do not use these pipes (0.8 mm thickness has to be 

strictly followed). 

  It is recommended to use pipes whose adhesion amount of oil is at or less than 40 mg / 10 m. 

At the same time, do not use pipes with dent, de-shape, and color change (especially inside). 

For refrigerant pipe installation, be aware of moisture and dirt do not get into the pipes, and make sure of no 
refrigerant leakage. 
◎

 The procedure of flaring and precautions 

a)  Cutting of pipes：use pipe cutter and cut the pipe slowly not to de-shape the pipe. 
b)  Removal of burrs on the edge of pipe (reamer or scraper) 

If the condition of pipe edge after the deburring is no good or if burrs attaches on the flaring, it may cause 
refrigerant leakage. Turn the pipe end down and perform deburring carefully. 

c)  Insert the flare nut (use the nut which is a part of the CZ parts) 
d) Flaring 

Ensure the cleanliness of clump bar and pipe, and perform flaring carefully. 
Use the existing flare tools or flare tools for R410A. Be aware that the sizes and dimensions of flaring is different 
in each flaring tool. If you use the existing flaring tools, use flaring gauge to measure the length of the flaring part. 

 

Piping 

size 

(mm) 

Dimensions “a” (mm) 

R22 

Dimensions “a” (mm)  

R410A/R32 

a

Bar

 

Nut outer diameter (mm)

Flare tools 

Flare tools 

for R410A 

Flare tools 

Flare tools 

for R410A 

R22 

R410A 

Clutch type 

Wing nut 

type 

Clutch type  Clutch type

Wing nut 

type 

Clutch type

R32 

6.35 (1/4") 

0.5 ~ 1.0 

1.0 ~ 1.5 

0 ~ 0.5 

1.0 ~ 1.5 

1.5 ~ 2.0 

0 ~ 0.5 

17 

17 

9.52 (3/8") 

0.5 ~ 1.0 

1.0 ~ 1.5 

0 ~ 0.5 

1.0 ~ 1.5 

1.5 ~ 2.0 

0 ~ 0.5 

22 

22 

12.70 (1/2") 

0.5 ~ 1.0 

1.5 ~ 2.0 

0 ~ 0.5 

1.0 ~ 1.5 

2.0 ~ 2.5 

0 ~ 0.5 

24 

26 

15.88 (5/8") 

0.5 ~ 1.0 

1.5 ~ 2.0 

0 ~ 0.5 

1.0 ~ 1.5 

2.0 ~ 2.5 

0 ~ 0.5 

27 

29 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

62 

(From the point of view of global environment protection, do not release CFCs into the atmosphere during installation 
work) 
1.  Connect the charging hose of manifold gauge to the service port of 3-way valve (pushing insect pin). 
2.  Fully open the handle Lo of manifold gauge and operate vacuum pump. 

(If the needle of the low-pressure gauge reaches the vacuum immediately, check 1 procedure again) 

3.  Perform vacuuming 15 minutes or more, and make sure low pressure gauge reaches to －0.1 MPa (-76cmHg). 

When the vacuuming completes, fully open the handle Lo of manifold gauge and stop the operation of vacuum 
pump, and leave it for 1 ~ 2 minutes. Then, remove the connection side of the charging hose of vacuum pump 
adopter after checking the needle of manifold gauge does not turn back. 

4.  Open the stem of 2-way valve to 90° in anti-clock wise, and close the 2-way valve after 10 seconds, and perform 

gas leakage test. 

5.  Remove the charge hose from the service port of 3-way valve, and open the stems of 2-way and 3-way valves 

(open the valves to anti-clock wise carefully, do not use full strength to open) 

6.  Tighten the service port cap with torque wrench 18

 

N•m (1.8 kgf•m) 

Tighten the caps of 2-way and 3-way valves with torque wrench 18 N•m (1.8kg f•m) 

7.  After the tightening of each cap, check gas leakage around the cap. 
 

Liquid side

Gas side

2-way valve

Valve stem caps

Service
port cap

Service port
valve core

-0.1 MPa

(-76cmHg)

Lo Handle

Vacuum pump

adaptor

Vacuum

pump

3-way valve

Manifold gauge

Hi Handle

High-pressure
gauge

Low-pressure

gauge

Charging hoses

Hex wrench

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

63 

1.  Connect the center charging hose of manifold gauge to the in-let side of recovery device. 
2.  Connect the valves of the discharge side of recovery device and liquid side of refrigerant cylinder with red hose 

(charging hose). 

3.  Connect the yellow float switch cable of the recovery device to the refrigerant cylinder. 
4.  Open the low pressure side valve of manifold gauge. 
5.  Slightly loosen the charging hose of in-let connecting side of recovery device and perform air purge. 
6.  Open the liquid valve of refrigerant cylinder and slightly loosen the charging hose in discharging side of recovery 

device, and perform air purge (the recovery cylinder needs slight inside pressure). 

7.  Insert electric plug of recovery device into electrical outlet (the fan operation starts). 
8.  Turn the valve 1 and 2 of recovery device to pressure equalization point. 
9.  After a few seconds, turn back the valve 1 and 2 to the original position. 
10.  Turn the switch of the recovery device to “ON”. (the compressor operation starts) 
11.  When the low pressure of manifold gauge is close to “0”, close the low pressure side valve, turn “OFF” the 

recovery device switch. 

12.  Remove the center charging hose of manifold gauge from the recovery device. 
 

(Liquid side)

(Indoor unit)

(Outdoor unit)

(Gas side)

Two-way valve

Close

Close

Three-way valve

Hi

Lo

Vacuum

Pump

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

64 

1.  Removing the air conditioning unit 

a)  Recovery of outdoor unit refrigerant by pumping down 

Press “forced cooling button” (as a general rule, since 1998 the name of cooling testing button is changed, 
and this name is unified within the air conditioning industry), and then you are able to start cooling operation 
in which the room temperature is low, and you can recover the refrigerant from the outdoor unit. 
 
1.  Check the valve stems of two-way and three-way valves are open by being turned to anti-clockwise 

(Remove the caps, and confirm the bars are fully open. Use hexagon wrench <4 mm> to open and close 
the valves). 

2.  Press the “Emergency Operation” button of the indoor units for five seconds and release [Forced cooling 

operation] (for old models, press “forced cooling” button). Then, operate the air conditioning unit for about 
10 minutes. 

3.  Turn the stem of the two-way valve to the clock-wise and close the valve. 
4.  After about 2 ~ 3 minutes, turn the stem of the three-way valve quickly to the clock-wise, and stop the 

operation. 

 

 

Caution: In the pump down operation, stop the compressor before removing the refrigerant pipes. 
 
If you do not stop the compressor operation, and if the valve is open and remove the refrigerant pipes, the air 
may be sucked into the system and causes extreme high temperature in the refrigerant cycle. This may result in 
rupture or injury, etc. 

 

5.  Attach and tighten the caps of two-way and three-way valves with torque wrench. 
6.  Remove the connecting pipes (liquid side and gas side). 

 

b)  Removal of indoor and outdoor units 

 
1.  Remove the connecting pipes and wires between the indoor and outdoor units. 
2.  Attach capping flare nuts on the edges of the pipes, connecting the indoor and outdoor units, in order to 

prevent dust and moisture get into the pipes. 

3.  Remove the indoor and outdoor units. 

 
2. Unit 

installation 

Use new refrigerant pipes for the installation, and perform air purging using vacuum pump and gas 
leakage testing stated in 14.5.1. 

When replacing the air conditioning units, you might use the existing pipes, but it is recommended to perform flaring 
again. In case of unit replacement, even if the unit is new refrigerant air conditioner, if the refrigerant oil is different, it 
may cause problem. Further, when re-using the existing refrigerant pipes, it is recommended to evacuate the pipes 
as much as possible, due to the reason that much refrigerant oil may be attached on the surface of the pipes. If the 
pipes are used without evacuation, the remaining refrigerant oil may cause under-performance and abnormal 
refrigerant cycle caused by non-compatibility of those oils. 

Do not operate air conditioning units inserting wrong (or mixed) refrigerant (R22, R410A, R32). It may cause mal-
function of the units, and at the same time, may cause serious incident such as rupture of the refrigerant cycle.