Fuel Supply - Riello G490 MXK Installation, Use And Maintenance Instructions

4.7

Fuel supply

Explosion danger due to fuel leaks in the pres-
ence of a flammable source.
Precautions: avoid knocking, attrition, sparks and
heat.
Make sure the fuel interception tap is closed be-
fore performing any operation on the burner.
The fuel supply line must be installed by qualified
personnel, in compliance with current standards
and laws.
WARNING
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.
Valve connection
electronic (XV1)
Setting the minimum gas flow (V2)
4.7.1 Gas train
This has been type-approved together with the burner, in accord-
ance with regulation EN 676, and is supplied as standard
(Fig. 14).
Key (Fig. 14)
1 Gas input pipe
2 Manual valve
3 Vibration damping joint
4 Pressure gauge with push-button cock
5 Valve including:
- filter (replaceable)
- working valve
- pressure adjuster
P1- Pressure up-line the filter
P2- Downstream pressure of valve
L - Gas train supplied
Installation
Gas valve
Quick coupling
Adjustment of maximum
gas flow (V1)
Metallic protective device
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.
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.
NOTE:
Pipe (T) between valve-Venturi allows compensation to oc-
cur for accidental occlusion of the suction line due to a re-
duction in gas delivered.
Test point downstream pressure
20075337
L1 - The responsibility of the installer
4
F
2 3
1
P1
L1
13 GB
Air/gas mixer
in the circuit
of the suction line
Compensation pipe (T)
Compensation pipe (T)
5
VS R VR
P2
L
Fig. 13
D8668
Fig. 14
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