Atlas Copco GA 37+ Instruction Book page 101

Instruction book
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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)
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D : depends on the HCO3- concentration or M-alkalinity (mval/l)
•
The values from A, B, C and D are found in below table:
Total A
dis s olve d
s olids (mg/l)
50-300
400-1000
Interpretation of the values obtained:
•
RSI < 6 boiler scale formation
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RSI 6-7 neutral water
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RSI > 7 corrosive water
A more detailed interpretation is given in following table:
RSI
RSI < 3.9
4.0<RSI<5.5
5.6<RSI<6.2
6.3<RSI<6.8
6.9<RSI<7.5
9096 3321 00
Te mpe rature B
(°C)
0.1 0-1 2.6
0.2 2-6 2.5
7-9 2.4
10-13 2.3
14-17 2.2
18-21 2.1
22-27 2
28-31 1.9
32-37 1.8
38-44 1.7
45-50 1.6
51-56 1.5
57-63 1.4
64-71 1.3
72-80 1.2
Tendency of the water
Very high scale formation
High boiler scale formation
Slight boiler scale formation
Neutral water
Slight corrosion at higher
temperature
Ca C
hardne s s
(ppm
CaCo )
3
10-11 0.6
12-13 0.7
14-17 0.8
18-22 0.9
23-27 1
28-34 1.1
35-42 1.2
44-55 1.3
56-69 1.4
70-87 1.5
88-110 1.6
111-138 1.7
139-174 1.8
175-220 1.9
230-270 2
280-340 2.1
350-430 2.2
440-550 2.3
560-690 2.4
700-870 2.5
880-1000 2.6
Action
Water cannot be used
Regular control and descaling is
necessary
M - D
Alkalinity
(mval/l
0.20-0.22 1
0.24-0.26 1.1
0.28-0.34 1.2
0.36-0.44 1.3
0.46-0.54 1.4
0.56-0.70 1.5
0.72-0.88 1.6
0.90-1.10 1.7
1.12-1.38 1.8
1.40-1.76 1.9
1.78-2.20 2
2.22-2.78 2.1
2.80-3.54 2.2
3.54-4.40 2.3
4.6-5.4 2.4
5.6-7.0 2.5
7.2-8.8 2.6
9.0-11.0 2.7
11.2-13.8 2.8
14.0-17.6 2.9
17.8-20.0 3
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