Water Softener
WINNI-mat
®
VGX
Order no. 215 188 040-inter Edited by: KONS-pha-rg G:\BA-188040-INTER-VGX.DOC
30
3.1 Recommended soft water hardness
3 °dH:
Minimum value acc. to DIN EN 12502 corrosion
protection
5.3 °f
0.53 mmol/l
4 – 6 °dH:
Optimum soft water (highest comfort).
7.1 – 10.7 °f
0.71 – 1.07 mmol/l
Sodium content
The local waterworks will inform you about the sodium content of the
raw water. When softening the water by 1 °dH (1.78 °f, 0.178 mmol/l),
the sodium content increases by approx. 8.2 mg/l. If the stipulations of
the German Drinking Water Act must be adhered to, the water cannot
be softened indefinitely. The permissible soft water hardness results
from the limit value of the sodium content and the raw water hard-
ness.
200 mg/l (limit value according to German Drinking Water Act)
– x mg/l (sodium content in raw water)
y mg/l (permissible sodium addition during the
softening process)
2
.
8
y
= Z °dH (maximum softening possible)
The raw water may be softened by a maximum of Z x °dH (Z x 1.78 °f,
Z x 0.178 mmol/l). Depending on the sodium content of the raw water,
a soft water hardness must be chosen which is below the maximum
value of 200 mg/l.
Example
Softening of drinking water
Raw water 28 °dH (50 °f, 5.0 mmol/l) contains 10.5 mg/l of sodium.
Permissible sodium addition during the softening process:
200 mg/l–10.5 mg/l = 189.5 mg/
This results in a maximum permissible softening of
mmol/l)
4.1
f,
(41
dH
23
8.2
189.5
This means:
Blending to at least
28 – 23 = 5°dH (9 °f, 0.9 mmol/l)
Table E-1: Conversion factors for water hardness
Water hardness
°dH
°f
mmol/l = mol/m³
German degrees
1 °dH
≙
1 1.78
0.178
French degrees
1 °f
≙
0.56 1
0.1
Alkaline earth ions 1mmol/l = mol /m³
≙
5.6 10
1
