22.11 – 5806712_07
25
EXPANSION VESSEL SETTING
The expansion tank volume is 6.3 gal. The standard value of the expansion tank pre-charge pressure is 21.8 psi, but this can be calibrated up to a maximum of 87.0 psi.
The expansion tank pressure setting has to be adjusted based on the difference in height (H) of the installation (see figure) according to the formula: p (rating) [psi] = H [ft] /
33.5 + 1.0.
For example: if level difference H is equal to 65.6 ft, the calibration value of the vessel will be 33.4 psi.
If the calibration value obtained from the formula is less than 21.8 psi (i.e. for H < 40.2), use the standard calibration.
Key
A
Expansion vessel
1
Check that highest utility is
not higher than 180.4 ft
2
Ensure that lowest utility can
withstand global pressure in
that position
H max (1) = 180.4 ft
H = 0 ft
H = 40.1 ft
Ptar = H /
33.5 + 1.0
Ptar = 21.8 psi
Ptar = 21.8 psi
H min (2)
A