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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 dierence in height (H) of the installation (see gure) according to the formula: p (rating) [psi] = H [ft] /
33.5 + 1.0.
For example: if level dierence 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
= 180.4 ft
H = 40.1 ft
Ptar = H / 33.5 + 1.0
Ptar = 21.8 psiPtar = 21.8 psi
(2)
A