5.Charging hose

The pressure resistance of the charging hose has been raised to match the higher pressure of R410A. The hose material has also been changed to suit HFC use, and the size of the fitting has been changed to match the manifold ports.

Fig. 4 Manifold gauge charging hose

Table 8 Difference between R410A and conventional charging hoses

 

 

Conventional hoses

 

R410A hoses

Pressure

Working pressure

3.4

MPa (35 kgf/cm3)

5.1

MPa (52 kgf/cm3)

resistance

 

 

 

 

 

Bursting pressure

17.2

MPa (175 kgf/cm3)

27.4

MPa (280 kgf/cm3)

Material

 

 

NBR rubber

HNBR rubber Nylon coating inside

 

 

 

 

 

 

6.Vacuum pump adaptor

When using a vacuum pump for R410A, it is necessary to install an electromagnetic valve to prevent the vacuum pump oil from flowing back into the charging hose. The vacuum pump adaptor is installed for that purpose. if the vacuum pump oil (mineral oil) becomes mixed with R410A, it will damage the unit.

Fig. 5 Vacuum pump adaptor

7.Electric gas leak detector for HFC refrigerant

The leak detector and halide torch that were used with CFC and HCFC cannot be used with R410A (because there is no chlorine in the refrigerant).

The present R134a leak detector can be used, but the detection sensitivity will be lower (setting the sensitivity for R134a at 1, the level for R410A will drop to 0.6).

For detecting small amounts of gas leakage, use the

electric gas leak detector for HFC refrigerant. (Detection

Fig. 6 Electric gas leak detector for HFC refrigerant

sensitivity with R410A is about 23 g/year).

 

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