Mitsubishi Electronics PUY-A36NHA2-BS, PUZ-A42NHA2-BS, PUZ-A30NHA2, PUZ-A18NHA2-BS, PUZ-A36NHA2 R22

3Tools for R410A (The

2-3. CAUTIONS FOR REFRIGERANT PIPING WORK

New refrigerant R410A is adopted for replacement inverter series. Although the refrigerant piping work for R410A is same as for R22, exclusive tools are necessary so as not to mix with different kind of refrigerant. Furthermore as the working pressure of R410A is 1.6 time higher than that of R22, their sizes of flared sections and flare nuts are different.

1Thickness of pipes

Because the working pressure of R410A is higher compared to R22, be sure to use refrigerant piping with thickness shown below. (Never use pipes of 0.7mm [7/256 inch] or below.)

Diagram below: Piping diameter and thickness

Nominal	Outside	Thickness : mm [inch]
dimensions[inch]	diameter (mm)	R410A	R22
1/4	6.35	0.8 [1/32]	0.8 [1/32]
3/8	9.52	0.8 [1/32]	0.8 [1/32]
1/2	12.70	0.8 [1/32]	0.8 [1/32]
5/8	15.88	1.0 [5/128]	1.0 [5/128]
3/4	19.05	—	1.0 [5/128]

2Dimensions of flare cutting and flare nut

The component molecules in HFC refrigerant are smaller compared to conventional refrigerants. In addition to that, R410A is a refrigerant, which has higher risk of leakage because of its working pressure is higher than that of other refrigerants. Therefore, to enhance air tightness and intensity, flare cutting dimension of copper pipe for R410A has been specified separately from the dimensions for other refrigerants as shown below. The dimension B of flare nut for R410A also has partly been changed to increase intensity as shown below. Set copper pipe correctly referring to cop- per pipe flaring dimensions for R410A below. For 1/2 and 5/8 inch, the dimension B changes.

Use torque wrench corresponding to each dimension.

Dimension A
						Dimension B
Flare cutting dimensions			Unit : mm [inch] Flare nut dimensions					Unit : mm [inch]
Nominal	Outside		Dimension A ( -+00.4)		Nominal	Outside		Dimension B
dimensions[inch]	diameter		R410A	R22	dimensions[inch]	diameter	R410A		R22
1/4	6.35	9.1	[11/32-23/64]	9.0	1/4	6.35	17.0	[43/64]	17.0
3/8	9.52	13.2	[1/2-33/64]	13.0	3/8	9.52	22.0	[7/8]	22.0
1/2	12.70	16.6	[41/64-21/32]	16.2	1/2	12.70	26.0	[1-3/64]	24.0
5/8	15.88	19.7	[49/64-25/32]	19.4	5/8	15.88	29.0	[1-9/64]	27.0
3/4	19.05		—	23.3	3/4	19.05		—	36.0

following table shows whether conventional tools can be used or not.)

Tools and materials	Use	R410A tools	Can R22 tools be used?
Gauge manifold	Air purge, refrigerant charge	Tool exclusive for R410A
Charge hose	and operation check	Tool exclusive for R410A
Gas leak detector	Gas leak check	Tool for HFC refrigerant
Refrigerant recovery equipment	Collection of refrigerant	Tool exclusive for R410A
Refrigerant cylinder	Refrigerant charge	Tool exclusive for R410A
Applied oil	Apply to flared section	Ester oil, ether oil and
		alkylbenzene oil(minimum amount)
Safety charger	Prevent compressor malfunction	Tool exclusive for R410A
	when charging refrigerant by
	spraying liquid refrigerant
Charge valve	Prevent gas from blowing out	Tool exclusive for R410A
	when detaching charge hose
Vacuum pump	Vacuum drying and air	Tools for other refrigerants can	(Usable if equipped
	purge	be used if equipped with adop-	with adopter for rever-
		ter for reverse flow check	se flow)
Flare tool	Flaring work of piping	Tools for other refrigerants	(Usable by adjusting
		can be used by adjusting	flaring dimension)
		flaring dimension
Bender	Bend the pipes	Tools can be used for other refrigerants
Pipe cutter	Cut the pipes	Tools can be used for other refrigerants
Welder and nitrogen gas cylinder	Weld the pipes	Tools can be used for other refrigerants
Refrigerant charging scale	Refrigerant charge	Tools can be used for other refrigerants
Vacuum gauge or thermis-	Check the degree of vacuum. (Vacuum	Tools can be used for other
tor vacuum gauge and	valve prevents back flow of oil and refri-	refrigerants
vacuum valve	gerant to thermistor vacuum gauge)
Charging cylinder	Refrigerant charge	Tool exclusive for R410A

:Prepare a new tool. (Use the new tool as the tool exclusive for R410A.)

:Tools for other refrigerants can be used under certain conditions.

:Tools for other refrigerants can be used.

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