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8.8 Leakage test
After the refrigerant piping has finished, execute a leakage test.
(1) Connect a nitrogen gas bomb as shown in the figure blow, and apply pressure.
(2) Please comply following steps to apply pressure:
STEP 1: Apply pressure 0.3Mpa (3.0kg/cm2G) for 3 minutes or more.
STEP 2: Apply pressure 1.5Mpa (15 kg/cm2G) for 3 minutes or more.
STEP3: Apply pressure 3.73Mpa (38kg/cm2G) for approx. 24 hours.
(3) Check the changment of pressure after 24 hours.
(4) Leaked position check: When a pressure down is detected in STEP1, STEP2, or STEP3,checking the
leakage at the connecting points. Check leakage with hearing sense, feeler, foaming agent, etc,and perform
re-brazing or re-tightening of flare if leakage is detected.
WARNING
1 Be sure to apply pressure to suction gas side, discharge gas side, and liquid side.
2 Never use “Oxygen”, “Flammable gas” and “Noxious gas” in an leakage test.
3 If there is no leakage,the pressure will not go down.Considering the change of ambient temp,
pressure drop by 0.01Mpa(0.1Kg/cm2G) per 10C is normal in 24 hours after pressure is
applied.
Chart
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8 refrIGerANT pIpING
