Viessmann VITOPLEX 100?LS - Appendix

26
Appendix
Water quality requirements according to TRD701
For steam operation it is advisable to feed back as much condensate as
possible to the feed water tank.
Treat the condensate with top−up water, so that the following conditions are
maintained:
Boiler feed water requirements
General requirements Colourless, clear and free
from undissolved
substances
pH value at 25ºC >9
El. conductivity at 25ºC mS/cm Only guide values
applicable to boiler water
Total alkaline earths
(Ca
2+
+Mg
2+
)
mmol/litre <0.015
Oxygen (O
2
) mg/litre <0.1
Bound carbon dioxide (CO
2
) mg/litre <25
Free carbon dioxide (CO
2
) mg/litre n. n.
Oxidisability (MnVII³MnII)
as KMnO
4
mg/litre <10
Oil, grease mg/litre <3
Boiler water requirements
General requirements Colourless, clear and free
from undissolved
substances
pH value at 25ºC 8.5 to 10
Acid capacity up to pH8.2 (K
S8.2
) mmol/litre 1 to 12
El. conductivity at 25ºC mS/cm <5000
Phosphate (PO
4
) mg/litre 10 to 20
The addition of phosphate is recommended, but is not always essential.
Conversion:
1mol/m
3
=5.6ºdH; 1ºdH=0.1792mol/m
3
; 1mval/kg=2.8ºdH
5692729 GB5692729 GB