Toshiba ESTIA HWS-802XWHM3-E Manuel D'installation page 18

Hydro Unit
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
Hot water temperature (°C)
0
4
5
10
15
20
25
30
35
40
45
▼ Fig. 7-15
Install an external expansion vessel when the capacity of the expansion vessel is insufficient.
17-EN
Water temperature and expansion coefficient
Expansion rate
0.0002
0.0000
0.0000
0.0003
0.0008
0.0017
0.0029
0.0043
0.0050
0.0078
0.0100
18
16
14
12
10
8
6
4
2
0
0 50 100
*Hot water temperature 55ºC
Hot water temperature (°C)
50
55
60
65
70
75
80
85
90
95
150 200 250
Water volume ( )
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Installation Manual
Expansion rate
0.0121
0.0145
0.0171
0.0198
0.0229
0.0258
0.0292
0.0324
0.0961
0.0967
300