– 18 –
Hydro Unit
Installation Manual
Expression for expansion vessel selection
V:
Necessary total tank capacity ( )
:
Water expansion coefficient at average hot water temperature
Vs: Total water amount in the system
P1: System pressure at tank setting position (MPaabs.)
(Pipe inner pressure during pump operation before heating device operates = water supply pressure)
P2: Maximum pressure used during operation at tank setting position (MPaabs.)
(= safety valve setting pressure)
* The absolute pressure value (abs.) is obtained by adding the atmospheric pressure (0.1 MPa (1 bar)) to the
gauge pressure.
▼
Tank selection method
Install an external expansion vessel when the capacity of the expansion vessel is insufficient.
Water temperature and expansion coefficient
Hot water temperature (°C)
Expansion rate
Hot water temperature (°C)
Expansion rate
0
0.0002
50
0.0121
4
0.0000
55
0.0145
5
0.0000
60
0.0171
10
0.0003
65
0.0198
15
0.0008
70
0.0229
20
0.0017
75
0.0258
25
0.0029
80
0.0292
30
0.0043
85
0.0324
35
0.0050
90
0.0961
40
0.0078
95
0.0967
45
0.0100
0
2
4
6
8
10
12
14
16
18
0
50
100
150
250
200
300
*Hot water temperature 55ºC
▼
Fig. 7-15
Expans
ion vessel volume(
)
Water volume ( )
17-EN
Summary of Contents for ESTIA HWS-1402XWHM3-E
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