Instruction Manual
106 
Appendix A - Heat Exchanger Corrosion Resistance 
Corrosion Resistance of Copper and Stainless Steel in Brazed Plate Heat Exchangers 
 - Points to Measure and Check in a Water Analysis 
The resistance guide provides the corrosion resistance of stainless steel type AISI 316 and pure 
Copper (99.9%) in water, to a number of important chemical factors. The actual corrosion is a 
very complex process influenced by many different factors in combination. 
Explanations: + Good resistance under normal conditions 
    0 Corrosion problems may occur especially when more factors are valued 0 
    - Use is not recommended 
Water 
Containing 
Concentration 
(mg/l or ppm) 
Time Limits - 
Analyze Before 
AISI 
316 
SMO 
254 
Copper 
Alloy 
Nickel 
Alloy 
Alkalinity 
(HCO
3
-
) 
< 70 
Within 24 Hours 
+ 
+ 
0 
+ 
70-300 
+ 
+ 
+ 
+ 
> 300 
+ 
+ 
0/+ 
+ 
Sulfate (SO
4
2-
) 
< 70 
No Limit 
+ 
+ 
+ 
+ 
70-300 
+ 
+ 
0/- 
+ 
> 300 
0 
0 
- 
+ 
HCO
3
-
/ SO
4
2-
> 1.0 
No Limit 
+ 
+ 
+ 
+ 
< 1.0 
+ 
+ 
0/- 
+ 
Electrical 
Conductivity 
< 10µS/cm 
No Limit 
+ 
+ 
0 
+ 
10-500 µS/cm 
+ 
+ 
+ 
+ 
> 500 µS/cm 
+ 
+ 
0 
+ 
pH 
< 6.0 
Within 24 Hours 
0 
0 
0 
+ 
6.0-7.5 
0/+ 
+ 
0 
+ 
7.5-9.0 
+ 
+ 
+ 
+ 
> 9.0 
+ 
+ 
0 
+ 
Ammonium 
(NH
4
+
) 
< 2 
Within 24 Hours 
+ 
+ 
+ 
+ 
2-20 
+ 
+ 
0 
+ 
> 20 
+ 
+ 
- 
+ 
Chlorides (Cl
-
)* 
< 300 
No Limit 
+ 
+ 
+ 
+ 
> 300 
0 
+ 
0/+ 
+ 
Free Chlorine 
(Cl
2
) 
< 1 
Within 5 Hours 
+ 
+ 
+ 
+ 
1-5 
+ 
+ 
0 
+ 
> 5 
0/+ 
+ 
0/- 
+ 
Hydrogen 
Sulfide (H
2
S) 
< 0.05 
No Limit 
+ 
+ 
+ 
+ 
> 0.05 
+ 
+ 
0/- 
+ 
Free (aggressive) 
Carbon Dioxide 
(CO
2)
< 5 
No Limit 
+ 
+ 
+ 
+ 
5-20 
+ 
+ 
0 
+ 
> 20 
+ 
+ 
- 
+ 
*See Chloride Content Table 










