54
AH/AY-X08CR
AH/AY-X10CR
AH/AY-X13CR
Table 10. Differences in Port Size between Conventional Manifold and That for R410A
Port size
Conventional manifold
Manifold for R410A
7/16 UNF
20 threads per inch
1/2 UNF
20 threads per inch
b) Charge Hose
As R410A is characterized by high pressure, the pressure resistance of the charge hose has been
increased. The material has also been changed to an HFC resistant type, and, as is the case of each
port of the manifold, the hose cap size has been changed. Furthermore, for prevention of gas pressure
reaction, a charge hose with a valve placed near the cap is also available.
Table 11. Differences between Conventional Charge Hose and That for R410A
Pressure
resistance
Conventional charge hose
Charge hose for R410A
3.4 MPa (34 kgf/cm
2
)
17.2 MPa (172 kgf/cm
2
)
NBR rubber
7/16 UNF
20 threads per inch
5.1 MPa (51 kgf/cm
2
)
27.4 MPa (274 kgf/cm
2
)
HNBR rubber
internally coated with nylon
1/2 UNF
20 threads per inch
Engineering material
Normal pressure
Breaking pressure
Cap size
c) Electronic Balance for Refrigerant Charging
As R410A belonging to the HFCs features high pressure and high evaporating speed, when R410A is
charged by using a charging cylinder, R410A in the cylinder cannot be kept in a liquefied state and
gasified refrigerant bubbles in the charging cylinder, it becomes difficult to read values. Therefore, it is
advisable to adequately use an electronic balance for refrigerant charging.
An electronic balance for refrigerant charging has higher strength due to its structure
with four points of support for refrigerant cylinder weight detection. As the charge hose connecting part
has two ports-one for R22 (7/16 UNF 20 threads per inch) and the other for R410A (1/2 UNF 20 threads
per inch)-it can also be used for charging the conventional refrigerant.
Two types of electronic balance for refrigerant charging are available-one for 10 kg cylinder and the other
for 20 kg cylinder.
Electronic balance for 10 kg cylinder ...... precision
±
2g
Electronic balance for 20 kg cylinder ...... precision
±
5g
Refrigerant is charged maunally by opening/closing the valve.
d) Torque Wrench (for nominal diameters 1/2 and 5/8)
Along with changes is flare nut sizes for enhanced pressure resisting strength, torque wrenches for
R410A differ in opposite side size.
Table 12. Differences between Conventional Wrenches and Those for R410A
For 1/2
(opposite x torque)
For 5/8
(opposite x torque)
Conventional torque wrench
Torque wrench for R410A
24 mm x 55 N m
(550 kgf cm)
27 mm x 65 N m
(650 kgf cm)
26 mm x 55 N m
(550 kgf cm)
29 mm x 65 N m
(650 kgf cm)
e) Flare Tool (clutch trpe)
A flare tool for R410A is provided with a large clamp bar receiving hole so that the projection of the copper
pipe from the clamp bar can be se at 0 ~ 0.5 mm in flare processing, and also features higher spring
strength for increased expansion pipe torque. This flare tool can also be used for R22 copper pipe.
f)
Gauge for Projection Adjustment (used when flare processing is made by using conventional flare
tool [clutch type] )
A gauge 1.0 mm in thickness which helps in easily setting the projection of the copper pipe from the
clamp bar at 1.0 ~1.5 mm.
g) Vacuum Pump Adapter
It is necessary to use an adapter for preventing vacuum pump oil from flowing back to the charge hose.
The charge hose connecting part has two ports-one for conventional refrigerant (7/16 UNF 20 threads
per inch) and the other for R410A. If the vacuum pump oil (mineral) mixes with R410A, a sludge may
occur and damage the equipment.
