Installation and connection
04.12.2015
22 / 48
Copyright
2014 by: WATERKOTTE GmbH. Subject to changes.
7.3.2.1
Groundwater quality
When using groundwater, the following limits (see table and diagram) must
be observed. If limits are exceeded, a separation heat exchanger is used.
The soldered plate heat exchanger consists of embossed stainless steel
plates 1.4401 or AISI 316. You must therefore take the corrosion behaviour
of stainless steel and the solder material, copper, into account.
Water contents and properties
Unit
Copper-soldered
plate heat exchanger (stand-
ard)
Nickel-soldered
plate heat exchanger
(optional)
pH value
7 - 9 (incorporating SI Index)
6 – 10
Saturation index SI (delta pH value)
-0.2 < 0 < +0.2
No specification
Total hardness
°dH
6 – 15
6 – 15
Conductivity
µS/cm
10...500
No specification
Filterable matter
mg/l
< 30
< 30
Chlorides
mg/l
See diagrams on next page. No chlorides permitted above 100 °C.
Free chlorine
mg/l
< 0.5
< 0.5
Hydrogen sulphide (H
2
S)
mg/l
< 0.05
No specification
Ammonia (NH
3
/NH
4+
)
mg/l
< 2
Sulphate
mg/l
< 100
< 300
Hydrogen carbonate
mg/l
< 300
No specification
Hydrogen carbonate / sulphate
mg/l
> 1.0
No specification
Sulphide
mg/l
< 1
< 5
Nitrate
mg/l
< 100
No specification
Nitrite
mg/l
< 0.1
No specification
Iron, dissolved
mg/l
< 0.2
No specification
Manganese
mg/l
< 0.1
No specification
Free aggressive carbon dioxide
mg/l
< 20
No specification
Table 1: Resistance of soldered plate heat exchangers to corrosion by substances contained in water
The values listed are guidelines which may vary under certain operating conditions. If you have questions,
please call us under Tel. : (+49) (0) 23 23 / 9 37 60
Permitted chloride contend depending on the temperature
1
10
100
1000
10000
0
25
50
75
100
Temperature [°C]
C
h
lo
ri
d
e
c
o
n
te
n
t
[m
g
/k
g
]
No working area
Working area without any problems
Not used
Usable without problems
