2.5
Cooling-water
The following cooling-water specification corresponds to a typical high-quality drinking water
specification. Check with your water supply authority if you are in doubt about the quality of
your supply.
Quality
Mechanically clean and optically
clear with no deposits or turbidity
pH value
6.0 to 8.0
Maximum calcium carbonate concentration
75 parts per million
Maximum chloride concentration
100 parts per million
Minimum oxygen concentration
4 parts per million
Minimum water cooling flow rate ( at 15
o
C)
See Table 2
Water temperature
see Table 2
Maximum water pressure
5 bar (gauge), 72 psig, 6 x 10
5
Pa
8
EXT250M Turbomolecular Pump
Figure 2 - Maximum allowed rate of pressure rise during venting:
backing pressure plotted against time
