Operation Manual

−11−−10−
Water Quality Criteria
Makeup water and cyclic water shall be the water within the range of water quality criteria
mentioned below.
If water quality is out of the range of criteria, it may cause a trouble such as scale adhesion and
corrosion.
Item
Cyclic water
(60°C
< ≦
90°C)
Makeup water
Standard items
pH (25
°C ) − 7.0−8.0 7.0−8.0
Electric conductivity (25
°C ) mS/m
≦
30
≦
30
Chloride ion mgCL
−
/L
≦
30
≦
30
Sulphate ion mgSO
4
2
−
/L
≦
30
≦
30
Acid consumption (pH4.8) mgCaCO
3
/L
≦
50
≦
50
Sulphate ion/Acid consumption −
≦
0.5
≦
0.5
Total hardness mgCaCO
3
/L
≦
70
≦
70
Calcium hardness mgCaCO
3
/L
≦
50
≦
50
Ionic silica mgSiO
2
/L
≦
30
≦
30
Reference items
Iron mgFe/L
≦
1. 0
≦
0.3
Copper mgCu/L
≦
1. 0
≦
0.1
Sulphide ion mgS
2
−
/L Not detected Not detected
Ammonium ion mgNH
4
+
/L
≦
0.1
≦
0.1
Residual chlorine mgCl/L
≦
0.1
≦
0.3
Free carbon mgCO
2
/L
≦
0.4
≦
4.0
Stability index − −