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INST
ALLA
TION
TECHNICAL INFORMATION
Hydraulic specifi cations
4.3
The hydraulic specifi cations represents the
pressure (available head for the central
heating system) as a function of the fl ow
rate.
Model
Activ A 18S
0
100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
0,00
0,06
0,12
0,18
0,24
0,30
0,36
0,42
0,48
0,54
0,60
Pression (bar)
Flow (l/h)
Fig. 4.3
Models
Activ A 25S - Activ A 30S
0
100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
0,00
0,06
0,12
0,18
0,24
0,30
0,36
0,42
0,48
0,54
0,60
Pression (bar)
Flow (l/h)
Fig. 4.4
The boiler load loss has already been re-
moved.
Flow rate with closed thermostatic
valves
The boiler is equipped with an automatic
by-pass, which protects the condensing pri-
mary exchanger.
In case of excessive reduction or total stop-
ping of water circulation in the heating plant
due to the closing of thermostatic valves or
circuit elements valves, by-pass ensures a
minimum water circulation inside the con-
densing primary exchanger.
The by-pass is calibrated to a differential
pressure of about 0.3-0.4 bar.
Expansion vessel
4.4
Note: this boiler is designed for opera-
tion only in a sealed central heating sys-
tem.
The height difference between the pressure
relief valve and the highest point in the sys-
tem may be 10m at most.
For greater differences, increase the pre-
load pressure in the expansion vessel and
the system, when cold, by 0.1 bar for each
additional 1m.
Fig. 4.5
Total capacity
l
7,0
Pre-load pressure
kPa
100
bar
1,0
Useful capacity
l
3,5
Maximum volume of water in the
system *
l
109
* Where conditions are:
Average maximum temperature of the sys-
•
tem is 85 °C
Initial temperature when fi lling up the sys-
•
tem is 10 °C.
For systems with volumes great-
er then the one indicated in the
above table, an additional expan-
sion vessel must be provided.
