NANO VDR 2600, Instruction Book, Page: 74 / 96

Parameter Unit
Single Pass
(65°C /
149°F)
Single
Pass
(95°C /
203°F)
Recirculating
(65°C / 149°F)
Closed
System
(65°C /
149°F) Closed
System
(95°C /
203°F)
12 Iron ppm < 1 < 0.2 < 1 < 1 < 0.2
13 Manganese ppm < 0.2 < 0.05 < 0.2 < 0.2 < 0.05
14 Copper ppm < 1 < 0.2 < 1 < 1 < 0.2
15 Ammonium ppm < 0.5 < 0.5 < 0.5 < 0.5 < 0.5
16
Suspended
Solids (max
10µ)
ppm < 10 < 1 < 10 < 10 < 1
17 Oil or Grease ppm < 1 < 1 < 1 < 1 < 1
18 Biology
CFU /
mL
< 10
5
< 10
3
< 10
5
< 10
3
< 10
3
Parameter Remarks
1 pH
For stainless steel systems without other materials, pH can
be down to 6.
For closed loop systems, higher pH values are possible
2 Conductivity
Conductivity and TDS linked with conversion factor
(theoretical factor possible, but practical determination
recommended at least once)
6
Ryznar Stability Index
(RSI)
Recommended actions : see table for RSI
7 Chlorine or shock treatment max. 2 ppm for 30 min/day
8 Chlorides (*) Limit 200 ppm applicable when RSI < 5.6 or RSI > 7.5
10 Sulphates Rejection < 2000 ppm. To be measured for calculating RSI.
11
Chemical Corrosion
Index Index = (Chl Sul Nitrates) / (M-Alkalinity)
(all expressed in meq/l)
15 Ammonium limit not applicable for Cu-free systems
16
Suspended Solids (max
10µ) No particles > 10µ allowed. (Particles <0.5µ not
considered).
18 Biology Anaerobic biology in closed system never allowed.
Table 2: Remarks on the technical specifications
Ryznar Stability Index (RSI)
The Ryznar Stability Index (RSI) is a parameter for predicting whether water will tend to dissolve or
precipitate calcium carbonate. The adhesion of scaling deposits and their effect are different on
different materials, but the equilibrium of the water (scaling or corrosive) is only determined by its
actual pH value and by the saturation pH value (pH
s
).
The saturation pH value is determined by the relationship between the calcium hardness, the total
alkalinity, the total solids concentration and the temperature.
The Ryznar Stability Index is calculated as follows :
RSI = 2*pH
s
- pH
Instruction book
72 2987 2020 00