20029918
14
GB
Installation
5.8
Fuel supply
The burners are teamed with one-piece pneumatic proportioning
gas valves, via which the amount of gas delivered, and hence the
output produced, can be modulated.
A signal reporting pressure detected in the air circuit is carried to
the pneumatic gas valve, which delivers an amount of gas in pro-
portion to the airflow produced by the fan.
To optimise the bulk, the gas train is assembled directly on the
body of the burner.
5.8.1
Gas train assembly
The connection valve-manifold allows compensating the acci-
dental occlusion of the suction line through the distributed gas re-
duction.
Air/gas mixer
Gas and combustive air are mixed inside the purging circuit (mix-
er), starting from the intake inlet.
Through the gas train, fuel is introduced into the intake air current
and optimal mixing commences with the aid of a mixer.
5.8.2
Gas valve
Tab. A
GAS TRAIN ASSEMBLY
D7375
D7155
D7380
Air/gas mixer
in the suction line circuit
Gas supply
Gas pressure downline
test point (
P1
)
Gas pressure downline
test point (
P2
)
Flange
Gas valve
Minimum gas flow
adjustment (
V1
)
Minimum gas flow
adjustment on the stabiliser (
V2
)
D7376
Gas compensation pipe
Fig. 11
Valve model
Honeywell VK4125V 1005B
Mixer model
Honeywell 45.900.444-001B
Gas line connection
½" inlet
Working temperature
-15°C/70°C
Max. working pressure
30 mbar
Min. working pressure
15 mbar
Max. inlet pressure
60 mbar
Valve class
B + B
Electrical supply
220-240 V
Protection level
IP 40 according to IEC 529
