COMMISSIONING
2.
Vacuum dry procedure
There are two methods of vacuum dry due to different construction environment: common
vacuum dry, special vacuum dry .
a.
Common vacuum dry procedure
•
Vacuum dry (for the first time)---connect the all-purpose detector to the inlet of liquid pipe and gas pipe, and run the vacuum
pump more than two hours (the vacuum pump should be below -755mmHg)
•
If the pump can't achieve below -755mmHg after pumping 2 hours, moisture or leakage point will still exist in the pipe . At this
time, it should be pumped hour more .
•
If the pump can't achieve -755mmHg after pumping 3 hours, please check if there are some leakage points .
•
Vacuum placement test: place hour when it achieves -755mmHg, pass if the vacuum watch shows no rising . If it rises, it
shows there's moisture or leakage point .
•
Vacuuming from liquid pipe and gas pipe at the same time .
•
Sketch map of common vacuum dry procedure .
b.
Special vacuum dry procedure
•
This vacuum dry method is used in the following conditions:
*
There's moisture when flushing the refrigerant pipe.
*
Rainwater may enter into the pipe .
•
Vacuum dry for the first time ······ 2h pumping
•
Vacuum destroy for the second time ······ Fill nitrogen to 0.5Kgf/cm²
Because nitrogen is for drying gas, it has vacuum drying effect during vacuum destroy . But if the moisture is too much, this
method can't dry thoroughly . So, please pay more attention to prevent water entering and forming condensation water .
•
Vacuum dry for the second time······1h pumping
Determinant: Pass if achieving below -755mmHg . If -755mmHg can't be achieved in 2h, repeat procedure
•
Vacuum placing test ······ 1h
•
Sketch map of special vacuum dry procedure
DUCTAIR II - 0808-E
Vacuum dry (2h)
Vacuum laying test (h)
Add refrigerant
• 3 •