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COMMISSIONING
Heating Water
The European Standard EN 14868 and the
directive VDI 2035 must be observed.
In particular, attention must be paid to the following stipu-
lations:
•
cording to EN 14868).
• Plants with
- continuous oxygen intake (e.g. underfloor heating
systems without diffusion proof plastic piping) or
- intermittent oxygen intake (e.g. where frequent refill-
ing is necessary)
must be equipped with
separate circuits.
•
least 1x yearly. According to the inhibitor manufacturer‘s
instructions, more frequent testing may be necessary.
•
water in existing installations (e.g. exchange of boiler)
conforms to VDI 2035.
The Directive VDI 2035 applies equally to the replace-
ment water.
• New and if applicable existing installations need to be
•
water are made of ferrous materials and stainless steel.
• On account of the danger of stress cracking corrosion
in the stainless steel section of the boiler the chloride,
nitrate and sulphate content of the heating water must
not exceed 50 mg/l.
• The pH value of the heating water should lie between
8.3 and 9.5 after 6-12 weeks of heating operation.
Filling and replacement water
• For a plant using Hoval boilers untreated drinking water
ing and replacement water. However, as not all drinking
VDI 2035. Should the mains water available not be
suited for use then it must be desalinated and/ or be
treated with inhibitors. The stipulations of EN 14868
must be observed.
•
to avoid overheating of the heating surfaces the values
given in the table should not be exceeded (dependent
on boiler performance ratings - for multi-boiler plants
rating of smallest boiler applies - and on the water con-
tent of the plant).
•
is used throughout the total service life of the boiler
must not exceed three times the water capacity of the
plant.
Maximum filling capacity based on VDI 2035
[mol/m
3
]
1
<0,1
0,5
1
1,5
2
2,5
3
>3,0
f°H
<1
5
10
15
20
25
30
>30
d°H
<0,56
2,8
5,6
8,4
11,2
14,0
16,8
>16,8
e°H
<0,71
3,6
7,1
10,7
14,2
17,8
21,3
>21,3
~mg/l
<10
50,0
100,0
150,0
200,0
250,0
300,0
>300
Conductance
2
<20
100,0
200,0
300,0
400,0
500,0
600,0
>600
Boiler size of the
individual boiler
50 to 200 kW
NO REQUI-
50 l/kW 20 l/kW 20 l/kW
always desalinate
200 to 600 kW
RE-
50 l/kW 50 l/kW 20 l/kW
over 600 kW
MENT
1
Sum of alkaline earths
2
If the conductance in
μ
S/cm exceeds the tabular value an analysis of the water is necessary.
5. Commissioning
5.1 Water
quality
NOTE:
No continous make-up of water should be
taking place during boiler operation. In
this event check where a leak may be oc-
curing or if pumping over is taking place.
