Unigas G225X, Manual Of Installation - Use - Maintenance

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PART I: SPECIFICATIONS
11
actuator are at the maximum opening. Refer to , showing the correct way to measure the gas pressure, considering the values of
pressure in combustion chamber, surveyed by means of the pressure gauge or taken from the boiler’s Technical specifications..
Measuring gas pressure in the combustion head
In order to measure the pressure in the combustion head, insert the pressure gauge probes: one into the combustion chamber’s pres-
sure outlet to get the pressure in the combustion chamber and the other one into the butterfly valve’s pressure outlet of the burner. On
the basis of the measured differential pressure, it is possible to get the maximum flow rate: in the pressure - rate curves (showed on the
next paragraph), it is easy to find out the burner’s output in Stm
3
/h (quoted on the x axis) from the pressure measured in the combu-
stion head (quoted on the y axis). The data obtained must be considered when adjusting the gas flow rate.
Gas pressure burner head vs natural gas flow rate
Curves are referred to pressure = 0 mbar in the combustion chamber!
Gas pressure
in
co
mb
usti
on hea
d
G225X M-
Stm
3
/h
Power [kW] Power [kW]
Gas pressure
in
combustion
h
ead
G270X M-
Stm
3
/h
G325X M-
Stm
3
/h
Power [kW] Power [kW]
1
2
4
3
Note: the figure is indicative only.Key
1 Generator
2 Pressure outlet on the combustion chamber
3 Gas pressure outlet on the butterfly valve
4 Differential pressure gauge
Fig. 4
ATTENTION : the burned gas rate must be read at the
gas flow meter. when it is not possible, the user can
refers to the pressure-rate curves as general information
only.