5-4
2. Analysis of water quality
Check the water quality of make up water to satisfy the water quality guideline “JRA GL-02-1994”.
About the analysis of water quality, contact a water treatment company.
3. Method of water treatment
(1) Blow down
Manage the recycling water quality to satisfy the water quality guideline “JRA GL-02-1994”.
(2) Addition of anticorrosive
Contact a water treatment company.
4. Precaution
In case of using a black pipe for cooling water line or chilled water line, use an anticorrosive for
black pipe to prevent adherence of the iron rust on copper tubes of the chiller.
(1) Adherence of fouling like the iron rust on copper tube may cause a corrosion. It is necessary to
add an anticorrosive for copper tube. Consult a water treatment company.
(2) Do not install the cooling tower near an exhaust gas outlet or ventilation port. Otherwise, the
quality of cooling water becomes poor and it causes corrosion problems.
(3) In case of installing a heat storage tank in chilled water line, there is a possibility to cause a
corrosion on the tubes by oxygen in chilled water or fouling of the heat storage tank. Install a
heat exchanger between the heat storage tank and the chiller or consult a service agent.
(4) When flashing of piping is performed at the first time, bypass the chiller to prevent foreign matter
from getting into it.
(5) In case of installing the chiller into an existing facility, there is a possibility to prevent a forming
the anti corrosion film on copper tubes by influence of a fouling of the existing piping. Consult
the service agent about the water treatment of post replacement.
5. Water quality standard
Water quality standard is shown below as an extract from JRA-GL02-1994.
Water quality standard for cooling water
Circulation
Make up
pH(at 25C(77F))
6.5 - 8.2
6.0 - 8.0
6.8 - 8.0
Yes
Yes
Electrical conductivity 25C
ms/m
80 or less
30 or less
40 or less
Yes
Yes
Chloride ion
mgCl
-
/l
200 or less
50 or less
50 or less
Yes
Sulfuric acid ion
mgSO
4
2-
/l
200 or less
50 or less
50 or less
Yes
Acid consumption (pH 4.8)
mgCaCO
3
/l
100 or less
50 or less
50 or less
Yes
Total hardness
mgCaCO
3
/l
200 or less
70 or less
70 or less
Yes
Calcium hardness
mgCaCO
3
/l
150 or less
50 or less
50 or less
Yes
Ion silica
mgSiO
2
/l
50 or less
30 or less
30 or less
Yes
Iron
mgFe/l
1.0 or less
0.3 or less
1.0 or less
Yes
Yes
Copper
mgCu/l
0.3 or less
0.1 or less
1.0 or less
Yes
Sulfide ion
mgS
2-
/l
No detected
No detected
No detected
Yes
Ammonium ion
mgNH
4
+
/l
1.0 or less
0.1 or less
1.0 or less
Yes
Residual chlorine
mgCl/l
0.3 or less
0.3 or less
0.3 or less
Yes
Free carbon dioxide
mgCO
2
/l
4.0 or less
4.0 or less
4.0 or less
Yes
Ryzner stability index
RSI
6.0 - 7.0
***
***
Yes
Yes
S
tand
ar
d
Re
fe
re
n
c
e
Circulation
Tendency
Cooling water line
Corrosion
Scale
One way