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17.1.4 Specifications
17.1.4.1 Specifications of fresh water was heat transfer medium in brazed heat
exchanger
Parameter
Quality Limits for Tap Water on the Secondary Side
Temperature
Below 60°C
pH
7 to 9
Alkalinity
60mg/I <HCO
3
<300mg/I
Conductivity
< 500μS/cm
Hardness
[Ca
+
, Mg
+
] / [HCO
3
-
] > 0.5
Chloride
< 200mg/l at 60°C
Sulphate
[SO
4
2-
] > 100mg/I and [HCO
3
-
] / [SO
4
2-
] > 1
Nitrate
NO
3
< 100mg/I
Chlorine
< 0.5mg/l
17.1.4.2 External filter
Solids in the water must be filtered.
Minimum filter mesh size required for the field supply external filter in the water inlet is 20 mesh.