McQuay MDS030AR Applications Manual page 91

Selection of vacuum pump
When selecting a vacuum pump, please pay attention to the follows:
The range of vacuum must be up to -755 mmHg
The vacuum pump should have a large exhaust volume(more than 40 litres/min).
Water boiling point(c)
40
30
26.7
24.4
22.2
20.6
17.8
15.0
11.7
7.2
0
Type of vacuum pump and the vacuity
Type
Vacuum pump with lubricant
Vacuum pump without lubricant
Sequence of vacuum drying
According to the different ambient, vacuum drying has two ways:
Ordinary vacuum drying
Operating sequence:
Connect the pressure gauge with the liquid pipe and gas pipe, then run the vacuum pump
for more than 2 hours to reach the vacuity of -755 mmHg.
After pumping for 2 hours, if the pressure is higher than -755 mmHg, or there is some
moisture, then pump it for 1 more hour.
After 3 hours pumping, if the pressure is still higher than -755 mmHg, please check to see
if there are some air leak gap.
When the pressure is -755mmHg, stop pumping and wait for 1 hour to see if the pressure
change. If the pressure change, that means there are some air leak gaps or there is some
moisture in the pipe.
Notes
Vacuum should be held both in the liquid pipe and the gas pipe at the same time.
Design & installation Guide For McQuay MDS Multi System
Pressure(mmHg)
55
36
25
23
20
18
15
13
10
8
5
Max. exhaust volume
0.02mmHg
100L/min
10mmHg
40L/min
0.02mmHg
50L/min
Vacuity(mmHg)
-705
-724
-735
-737
-740
-742
-745
-747
-750
-752
-755
Application
Vacuum drying Air discharge
Suitable
Unsuitable
Unsuitable
Suitable
Suitable
Suitable
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