21
5.8
Expansion vessel
The expansion vessel installed on the boilers has the following
characteristics:
Description
U/M
MURELLE HT
25
30
35
Total capacity
l
10,0
Prefilling pressure
kPa
100
bar
1,0
Useful capacity
l
5,0
Maximum system content (*)
l
124
(*) Conditions of:
Average maximum temperature of the system 85°C
Start temperature at system filling 10°C.
m
CAUTION
– For systems with water content exceeding the max-
imum system content (as indicated in the table) an
additional expansion vessel must be prearranged.
– The difference in height between the relief valve
and the highest point of the system cannot exceed
6 metres. If the difference is greater than 6 metres,
increase the prefilling pressure of the expansion
vessel and the system when cold by 0.1 bar for each
meter increase.
5.9
Circulation pump
The flow-head performance curve available for the heating sys-
tem is shown in the graph below.
RESIDUAL HEAD (mbar)
0
0
800
1000
1200
600
400
200
100
200
300
400
500
600
700
25
30
35
FLOW (l/h)
Fig. 32
m
CAUTION
The appliance is equipped with a by-pass which en-
sures water circulation in the boiler when the thermo-
static valves or cocks are used in the system.
