25
Performing air tightening test
f
Use tools for R-410A only to prevent the inflow of foreign substances and to resist the internal pressure.
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Use dry Nitrogen gas to do an airtight test as below.
Apply pressure to the liquid side pipe, gas
side pipe with Nitrogen gas of 4.1 MPa (gauge
pressure).
If you apply pressure more than 4.1 MPa (gauge pressure), the pipes
may be damaged. Apply pressure using pressure regulator.
Continue to apply pressure for minimum
24 hours to check if the pressure drops.
After applying Nitrogen gas, check the change of pressure using
pressure regulator.
If the pressure drops, check if there is a gas leak.
If the pressure is changed, apply soapy water to check the leak. Check
the pressure of the gas again.
Maintain 1.0 MPa (gauge pressure) of the
pressure before performing vacuum drying and
check for further gas leak.
After checking first gas leak, maintain 1.0 MPa (gauge pressure) to check
for further gas leaks.
Nitrogen gas
t
If the joint of high pressure side is disconnected and the nitrogen gas come into contact with human body, injury
may occur. Tighten the joint connection firmly to prevent dangerous situation.
CAUTION
