Haier AS072XVERA Service Manual page 14

■Piping material
1. Use the correct refrigerant piping and materials for R410A
2. For the pipe wall thickness, see the table below:
Pipe diameter
Φ6.35
Pipe wall thickness 0.8
Note: Always observe and comply with the local regulations when installing the refrigerant piping.
■Tools
R410A work requires a number of special tools (* symbol). Since the tools used in R22 work
cannot be used for R410A, provide the tools separately.
Tool name
Pipe cutter
*Flaring tool
*Torque wrench
Expander
Pipe bender
Nitrogen gas
Welder
*Gauge manifold
*Charging hose
*Vacuum pump (with
adapter)
Electronic scale
Gas leakage detector
■Work precautions
Refrigerant check: Before work, check the used refrigerant and prepare materials matched to the
refrigerant.
Refrigerant piping: Observe the basics of refrigerant piping to avoid the unnecessary problems. In
addition, when performing the welding work, seal in the nitrogen gas to the pipes, and prevent it
from the oxidation.
Leak pressure detection: Perform seal detection and make sure there is no refrigerant leakage.
Vacuum drying: If the vacuum pump has not the reverse flow check mechanism, use the pump
together with a reverse flow check adapter.
Additional refrigerant: Charge a suitable amount of refrigerant with a special R410A gauge
manifold and charging hose.
Commercial Air Conditioner
Φ9.52 Φ12.7
0.8 0.8
Process and application
Piping cutting
Pipe flaring work
Flare nut connection
Expansion at pipe connection
Pipe bending work
Pipe oxidation prevention
Pipe brazing
Vacuum evacuation and
charging operation check
Gas leakage test
-14-
Model: AU18/222XFERA
AS072/092/122XVERA
Φ15.88
1.0
Refrigerant piping work
Air tightness test
refrigerant Air tightness test
Refrigerant
charging
Vacuum drying
Refrigerant
charging
Φ19.1
1.2
additional
additional