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TECHNICAl INFoRMATIoN
4.5 Hydraulic specifications
The hydraulic specifications in Fig. 4.3 rep-
resent the pressure (available head for the
central heating system) as a function of the
flow rate.
The load loss due to the boiler has already
been subtracted.
Fig. 4.3
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0
200
400
600
800 1000 1200 1400
0
10
20
30
40
kPa bar
l/h
60
50
output with thermostat cocks shut off
The boiler is equipped with an automatic by-
pass valve (46on page 23), which protects
the condensing primary exchanger.
In case of excessive reduction or total
blockage of water circulation in the cen-
tral heating system owing to closure of the
thermostatic valves or system component
cocks, the by-pass valve ensures a mini-
mum flow of water through the primary heat
exchanger.
4.6 Expansion vessel
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 10 m 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 1 m.
For 24 Kw and 28 Kw
Fig. 4.4
Capacity
l
6,0
Pre-load pressure
kPa
100
bar
1,0
Maximum volume of water in the
system *
l
94
* Where conditions are:
• Average maximum temperature of the
system is 85 °C
• Initial temperature when filling up the sys-
tem is 10 °C
For systems with volumes
greater than 94l, an additional
expansion vessel must be pro-
vided.
Summary of Contents for Riva Plus HE M296.24SC
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