18
REFRIGERANT PIPING
Refrigerant Piping
Tools and Instruments -
The pressure of refrigerant R410A is about 1.6 times higher than that of currently used R-22 refrigerant.
Therefore it is more susceptible to impurities such as moisture, acid, grease, etc. As this is a new refrigerant,
the refrigeration oil also has to be changed. Care should be taken not to allow moisture, impurities, existing
refrigerant and refrigeration oil to come into the circulation system.
To avoid entry of old refrigerant and refrigeration oil, the size of the alignment fitting for refrigerant charging
and the flare nut size is different from the existing one. Use the following tools exclusively for R410A.
Be sure to use new refrigerant pipes (old piping used by refrigerant R-22 replaced reused after cleaning is
not allowable.)The measuring machine or tool that may come in contact with the refrigerant should be used
exclusively for the new refrigerant.
Symbolic description
：
○
Can be used by new and old refrigerant
□
Only for new refrigerant R410A (R-22 not applicable)
Measuring Instrument,
tool
Interchange
with R-22
Reason of Non-Interchange and Attention
(
◎
: Strictly Required)
Application
R
e
fr
ig
e
ra
n
t
p
ip
in
g
Pipe cutter
○
For refrigerant pipe
cutting and burr
removing.
Pipe expander
○□
To ensure compression resistance of the flare
for R410A, the flare opening must be enlarged.
In the case of continual use of the existing item,
a washers (1mm) matching with the pipe
expansion adjustment must be used. In the
case of 1/2H copper pipe, it is impossible to
process.
Expanding flare of
the refrigerant
pipe.
Washers for pipe
expansion
adjustment
□
For copper pipe
overhang size
control when
processing flares.
Pipe bender
○
If using a 1/2H copper pipe, it is impossible to
process. Use the connection of a bend to be
welded instead.
For refrigerant pipe
bending.
Pipe expansion
tool
○
If using a 1/2H copper pipe, it is impossible to
process. Use the connection of a fitting to be
welded instead.
For refrigerant pipe
expanding.
Torque wrench
□
Sizes of
¯
12.7,
¯
15.88 wrenches should
increase 2 mm. Existing item must not be used.
For tightening flare
nuts
○
Can be used for
¯
9.53, and
¯
19.05
Welding machine
○
Follow correct welding operation. (Flame
adjustment, heating method, heating
temperature, weld material selection.)
For welding of
refrigerant pipes
Nitrogen gas
○
More strict control of dust entrance.
(Observe nitrogen gas blowing in when
welding)
Avoiding oxidation
when welding and
for air-tightness
test
Refrigeration oil
for applying it on
the flare
□
Use of mineral oil for R-22 is prohibited. Only
synthetic oil corresponding to the product can
be used.
Synthetic oil has a higher tendency for moisture
absorption. Do not store it in a humid place.
Smearing on the
flare face and for
maintenance
Summary of Contents for RAS-NP10CTS
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