n
Free chlorine consisting of disinfectant, for example, and water con-
taining chloride will cause pitting corrosion in the cooling water circuit.
n
Distilled, deionized and demineralized water are unsuitable due to their
reactivity and will cause corrosion in the cooling water circuit.
n
Sea water is unsuitable due to its corrosive properties and will cause
corrosion in the cooling water circuit.
n
Iron particles and water containing iron will cause corrosion in the
cooling water circuit.
n
Hard water is unsuitable for cooling due to the high lime content and will
lead to calcification of the cooling water circuit.
n
Cooling water containing suspended matter is unsuitable.
n
Untreated, unpurified water such as river water or cooling tower water is
unsuitable due to its microbiological content (bacteria), which can settle
inside the cooling water circuit.
Data
Value Unit
pH value
7.5
-
9.0 ---
Hydrocarbonate [HCO
3
-
]
70
-
300 mg/L
Chloride
< 50 mg/L
Sulfate [SO
4
2-
]
< 70 mg/L
Ratio hydrogen carbonate [HCO
3
-
] / sul-
fate [SO
4
2-
]
> 1 ---
Total water hardness
4.0
-
8.5 °dH
Electrical conductivity
30
-
500 μS/cm
Sulfite (SO
3
2-
)
< 1 mg/L
Free chlorine gas (Cl
2
)
< 0.5 mg/L
Nitrate (NO
3
-
)
< 100 mg/L
Ammonia (NH
3
)
Not permitted ---
Iron (Fe), dissolved
< 0.2 mg/L
Manganese (Mn), dissolved
< 0.05 mg/L
Aluminum (Al), dissolved
< 0.2 mg/L
Free aggressive carbon dioxide (CO
2
)
Not permitted ---
Hydrogen sulfide (H
2
S)
Not permitted ---
Algae growth
Not permitted ---
Suspended matter
Not permitted ---
4.6 Connecting the cooling water
This section is relevant for:
n
Water-cooled devices
Suitable cooling water quality
V6
Integral Process Thermostats and High-Temperature Thermostats
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