Chemische Eigenschaften Des Wassers - Thermo-Tec RAS MC Kp Serie Bedienhandbuch

4.12. Chemische Eigenschaften des Wassers

Die folgende Tabelle zeigt die wichtigsten Parameter, die die Wasserqualität bestimmen. Diese Werte müssen
eingehalten werden, um Korrosion oder Ablagerungen jeglicher Art zu verhindern, die sowohl die Wärmeleistung
als auch die Lebensdauer des Wärmetauschers auf der Nutzerseite gefährden würden. Zu diesem Zweck sollten die
chemisch-physikalischen Eigenschaften des Wassers jährlich überprüft werden.
EXPLANATIONS:
WATER CONTENT CONCENTRATION
(mg/l or ppm)
-
Alkalinity (HCO )
< 70
3
70-300
> 300
[1] 2-
Sulphate (SO )
< 70
4
70-300
> 300
- 2-
HCO / SO
> 1.0
3 4
< 1.0
Electrical conductivity < 10 μS/cm
10-500 μS/cm
> 500 μS/cm
[2]
pH < 6.0
6.0-7.5
7.5-9.0
>9.0
+
Ammonium (NH )
< 2
4
2-20
>20
-
Chlorides (Cl ) <100
100-200
Please also see
200-300
table below
>300
Free chlorine (Cl )
< 1
2
1-5
> 5
Hydrogen sulfide (H S) < 0.05
2
>0.05
Free (aggressive) < 5
carbon dioxide (CO )
5-20
2
> 20
Total hardness (°dH) 4.0-8.5
[1] -
Nitrate (NO )
< 100
3
> 100
[3]
Iron (Fe) < 0.2
> 0.2
Aluminium (Al) < 0.2
> 0.2
[3]
Manganese (Mn)
< 0.1
> 0.1
[1]
Sulfates and nitrates works as inhibitors for pitting corrosion caused by chlorides in pH neutral environments
[2]
In general low pH (below 6) increase corrosion risk and high pH (above 7.5) decrease the corrosion risk
[3] 3+ 4+
Fe and Mn are strong oxidants and may increase the risk for localised corrosion on stainless steels
[4]
in combination with brazing material copper
SiO above 150ppm increase the risk of scaling
2
CHLORIDE
CONTENT 30°C
= 10 ppm SS 304
= 25 ppm SS 304
= 50 ppm SS 304
= 80 ppm SS 316
= 150 ppm SS 316
= 300 ppm SS 316
> 300 ppm Ti / 254 SMO
THERMO-TEC Bedienhandbuch - Kaltwassersatz - RAS / Wärmepumpe - PAS
+ Good resistance under normal conditions
0 Corrosion problems may occur especially when more factors are valued 0
- Use is not recommended
TIME LIMITS
Analyze before
Within 24 h
No limit
No limit
No limit
Within 24 h
Within 24 h
No limit
Within 5 h
No limit
No limit
No limit
No limit
No limit
No limit
No limit
MAXIMUM TEMPERATURE
60°C 80°C
SS 304 SS 304
SS 304 SS 304
SS 304 SS 316
SS 316 SS 316
SS 316
[4]
SS 316 Ti / 254 SMO
SS 316
[4]
Ti / 254 SMO Ti / 254 SMO
SS 316
Ti / 254 SMO Ti / 254 SMO Ti / 254 SMO
Plate Material
AISI 304 AISI 316 254 SMO COPPER NICKEL
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
0 0 0
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
0 + +
- + +
- - +
+ + +
- - 0
- - -
+ +
+ +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
+ + +
120°C 130°C
SS 304 SS 316
[4]
SS 316
SS 316
SS 316 Ti / 254 SMO
[4]
Ti / 254 SMO
Ti / 254 SMO
Ti / 254 SMO
Ti / 254 SMO
Brazing Material
STAINLESS
STEEL
0 + +
+ + +
0/+ + +
+ + +
0/- + +
- + +
+ + +
0/- + +
0 + +
+ + +
0 + +
0 + 0
0 + +
+ + +
0 + +
+ + +
0 + +
- + +
+ + +
+ + +
+ + +
0/+ + -
+ + +
0 + -
0/- + -
+ + +
0/- + +
+ + +
0 + +
- + +
+ + +
+ + +
0 + +
+ + +
0 + +
+ + +
0 + +
+ + +
0 + +
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