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Refrigerant pipe length
Single
Allowable pipe length (m)
Model
Total length L
GV110
30
Model
Liquid side
GV110
Ø9.5
27-EN
Height difference (Indoor-outdoor H) (m)
Indoor unit: Upper
Outdoor unit: Lower
30
Pipe diameter (mm)
Number of bent portions
Gas side
Ø15.9
Indoor unit
Outdoor unit
6
Air purging
Airtight test
After completing the refrigerant piping work, perform an airtight test. Connect a nitrogen gas cylinder and
pressurize the pipes with nitrogen gas as follows to conduct the airtight test.
30
Low pressure gauge
Charge port
10 or less
Gas leak check
Step 1....Pressurize to 0.5 MPa (5 kg/cm²G) for 5 minutes or longer.
Step 2....Pressurize to 1.5 MPa (15 kg/cm²G) for 5 minutes or longer.
Step 3....Pressurize to 4.15 MPa (42 kg/cm²G) for 24 hours. ................ Micro leaks can be discovered.
(However, note that when the ambient temperature differs during pressurization and after 24 hours, the pressure
will change by approximately 0.01 MPa (0.1 kg/cm²G) per 1°C, so this should be compensated.)
If the pressure drops in steps 1 through 3, check the connections for leakage.
Check for leaks with foaming liquid, etc., take steps to fix the leaks such as brazing the pipes again and
tightening the flare nuts, and then perform the airtight test again.
* After the airtight test is completed, evacuate the nitrogen gas.
– 14 –
High pressure gauge
Gauge manifold
V
V
L
H
Pressure reducing valve
Nitrogen gas
Major leaks can be discovered.
CAUTION
Never use oxygen, flammable gas,
or noxious gas for the airtight test.
28-EN
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