V Ratio
Adjustable ratio between pressure at the burner p
of the comparison membranes.
p
= (p
- p
) and
Br
Br
F
p
= (p
- p
)
L
L
F
Correction of zero-point N
Correction of the difference in weight in case of different lever lengths between the air comparison membrane and gas
comparison membrane (V 1:1).
Possibility of varying original ratio; parallel shift (offset).
Effective pressure difference Dp
The effective drop (or difference) relative to combustion chamber pressure is decisive for both gas and air total flow
rates.
COMPACT VALVE SEAL CONTROL DEVICE VPS 504
A seal control device to be fitted to the MULTIBLOC unit can be supplied on
request.
CALIBRATION OF AIR PRESSURE SWITCH
The air pressure switch serves as failsafe or lock-out for the burner if comburent air
pressure is cut off. It should be calibrated at approximately 15% lower than the air
pressure level at the burner when the latter is operating at its rated output on 1st
stage, and by ensuring that the CO figure remains lower than 1%.
CALIBRATION OF MINIMUM GAS PRESSURE SWITCH
The minimum gas pressure switch serves to prevent the burner from being started up or to shut it down. If the gas pressure
falls below the minimum required level, this setting should be 40% lower than the gas pressure obtained with the burner
operating at maximum delivery.
and air pressure p
Br
and Dp
Br
L
- 43
-
. The following pressure differences act on the whole
L