NANO VDR 2600, Instruction Book, Page: 75 / 96

Symbol Explanation
pH Measured pH (at room temperature) of water sample
pH
s
pH at saturation
The pH
s
is calculated by using :
pH
s
= (9.3 + A + B) - (C + D)
Symbol Calculation
A (
10
log(TDS) - 1) / 10
B 13.12 x
10
log(°C+273) + 34.55
C
10
log(Ca
2+
) - 0.4 (Ca
2+
expressed as ppm CaCO
3
)
D
10
log(M-Alkalinity) (M-Alkalinity expressed as ppm CaCO
3
)
RSI and chloride limitation
RSI
Chlorid
e limit
Water condition
Maximum 65°C /
149°F Maximum 95°C /
203 °F
RSI<3.9
200
ppm
Very high scale formation
Water cannot be
used.
Not applicable.
4.0<RSI<5.5
200
ppm
High scale formation
Regular control and
descaling operation
necessary.
Not recommended
for plate heat
exchangers
Not applicable.
5.6<RSI<6.2
350
ppm
Slight scale formation
Water treatment not
necessary.
Occasional
inspection
recommended.
Not applicable.
6.3<RSI<6.8
500
ppm
Neutral water
Water treatment not
necessary.
Occasional
inspection
recommended. Water treatment not
necessary.
Occasional
inspection
recommended.
6.9<RSI<7.5
350
ppm
Slight corrosion
Water treatment not
necessary.
Occasional
inspection
recommended. Water treatment not
necessary.
Occasional
inspection
recommended.
7.6<RSI<9.0
200
ppm
Strong corrosion
Regular control
necessary.
Avoid interruption of
operation Regular control
necessary.
Avoid interruption of
operation
Instruction book
2987 2020 00 73