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4.5 Air Tight Test
(1) The stop valves should be closed completely (factory-setting). Do not open the stop valves until all the
refrigerant piping connections, air tight test, and vacuum have been completed.
(2) The refrigerant used for the outdoor unit is R410A. Use the pressure gauge and the charging hose for
exclusive use of R410A.
(3) Connect the indoor/outdoor units with refrigerant piping. Mounted the piping to a stable wall or ceiling
with the piping clamp at interval 1.5 meters. Otherwise, the piping may be damaged.
(4) Securely insulate the gas piping side and liquid piping side individually.
(5) Connect the mainfold gauge and the charging hoses to the check joints of the stop valves with a nitrogen
tank. Perform the air tight test at 4.15 MPa for the test pressure.
(6) For the air tight test, please use a leak detector or forming agent to detect the joints and stop valves for
the piping connection. If there is leakage, please repair it and repeat the air tight test operation.
(7) If there is no leakage, the nitrogen gas should be discharged from the refrigerant pipes and the air tight
test is finished.
(8) Make sure to insulate the joints for the piping connection as well. Seal the gap between the piping cover
and pipes with the field-supplied packing after insulation work is completed.
NOTICE
●
The air tight test should be performed on the gas stop valve and the liquid stop valve simultaneously.
Otherwise, the air tight test is invalid.
●
Use the pressure gauge and the charging hose for exclusive use of R410A.
Piping Clamp
Gas Piping
Liquid
Piping
Note:
Due to gas and liquid piping will stretch or contact at
different
rates
due
to
changing refrigerant
temperatures.
Do not fasten gas and liquid piping
together.
Distortion
and
deformation
of
the
piping
can
occur.
Procedure
Completion of
Applying
Check of
Pass
Ref. Piping
Nitrogen Gas
Pressure Decrease
Repairing of
Leakage
Part