Expansion Vessel - Mitsubishi Electric Ecodan HUS210FTC4ST Installation Manual

Expansion Vessel

20
Each Mitsubishi Electric pre-plumbed cylinder is supplied with a suitably sized expansion vessel (white) for the
associated volume of potable water.
Model
Expansion Vessel Size
In the case of a sealed primary circuit an additional expansion vessel will be required, this needs to be sized to
accommodate the expansion within the entire heat emitter circuit and associated pipework. The installer will need
to make this selection based upon the below sizing equation.
Graph above is for the following values:
ε : at 70ºC = 0.0229
* 30% safety margin is added
FTC4 Installation Manual
28
HU150FTC4ST HU180FTC4ST HU(S)210FTC4ST
12 Litres 19 Litres
Expansion Vessel Sizing
P : 0.1MPa P : 0.3MPa
1 2
HU(S)250FTC4ST
19 Litres 19 Litres
Where:
V : Necessary expansion vessel volume
ε : Water expansion co-efficient
G : Total volume of water in the system
P : Expansion vessel setting pressure
1
P : Max pressure during operation
2
HU(S)300FTC4ST
24 Litres