Atlas Copco GA90

103
Instruction book
9096 3313 00
• B : depends on the highest cooling water temperature (°C),For GA/GR units take T = 75 °C
• C : depends on the calcium hardness (ppm CaCO3)
• D : depends on the HCO3- concentration or M-alkalinity (mval/l)
•
The values from A, B, C and D are found in below table:
Interpretation of the values obtained:
• RSI < 6 boiler scale formation
• RSI 6-7 neutral water
• RSI > 7 corrosive water
A more detailed interpretation is given in following table:
Total
dissolved
solids
(mg/l)
A
Temperature
(°C)
B Ca
hardness
(ppm
CaCo
3
)
C M-
Alkalinity
(mval/l
D
50-300 0.1 0-1 2.6 10-11 0.6 0.20-0.22 1.0
400-1000 0.2 2-6 2.5 12-13 0.7 0.24-0.26 1.1
7-9 2.4 14-17 0.8 0.28-0.34 1.2
10-13 2.3 18-22 0.9 0.36-0.44 1.3
14-17 2.2 23-27 1.0 0.46-0.54 1.4
18-21 2.1 28-34 1.1 0.56-0.70 1.5
22-27 2.0 35-42 1.2 0.72-0.88 1.6
28-31 1.9 44-55 1.3 0.90-1.10 1.7
32-37 1.8 56-69 1.4 1.12-1.38 1.8
38-44 1.7 70-87 1.5 1.40-1.76 1.9
45-50 1.6 88-110 1.6 1.78-2.20 2.0
51-56 1.5 111-138 1.7 2.22-2.78 2.1
57-63 1.4 139-174 1.8 2.80-3.54 2.2
64-71 1.3 175-220 1.9 3.54-4.40 2.3
72-80 1.2 230-270 2.0 4.6-5.4 2.4
280-340 2.1 5.6-7.0 2.5
350-430 2.2 7.2-8.8 2.6
440-550 2.3 9.0-11.0 2.7
560-690 2.4 11.2-13.8 2.8
700-870 2.5 14.0-17.6 2.9
880-1000 2.6 17.8-20.0 3.0
RSI Tendency of the water
Action
RSI < 3.9 Very high scale formation
Water cannot be used
4.0<RSI<5.5 High boiler scale formation
Regular control and descaling is
necessary
5.6<RSI<6.2 Slight boiler scale formation
6.3<RSI<6.8 Neutral water
6.9<RSI<7.5
Slight corrosion at higher
temperature