5.10.2 Gas Train; 5.10.3 Gas Train Installation; 5.10.4 Gas Pressure - Riello RS 68/M BLU Installation, Use And Maintenance Instructions

5.10.2 Gas train

Type-approved in accordance with EN 676 and supplied
separately from the burner.
To select the correct gas train model, refer to the manual "Burner-
gas train combination" supplied with the unit.

5.10.3 Gas train installation

Disconnect the power supply using the system
main switch.
DANGER
Check that there are no gas leaks.
Pay attention when handling the train: danger of
crushing of limbs.
Make sure that the gas train is properly installed
by checking for any fuel leaks.
The operator must use the required equipment
during installation.
The train can enter the burner from the right or left side,
depending on which is the most convenient, see Fig. 22. The gas
train must be connected to the gas connection 1)(Fig. 22), using
the flange 2), seal 3) and screws 4) supplied with the burner.
The gas solenoid valves must be as close as
possible to the burner to ensure that the gas
reaches the combustion head within the safety
time of 3s.
ATTENTION
Make sure that the maximum pressure necessary
for the burner is within the calibration range of the
pressure regulator.
Installation
See the accompanying instructions for the adjustment of the gas
train.

5.10.4 Gas pressure

Tab. K indicates the pressure drops of the combustion head and
gas butterfly valve depending on the burner operating output.
kW
350
500
650
750
860
600
760
955
1170
1300
Data of head thermal power and gas pressure
refer to operation with gas butterfly valve fully
open (90°).
ATTENTION
The values shown in Tab. K refer to:
– Natural gas G 20 NCV 9.45 kWh/Sm
– Natural gas G 25 NCV 8.13 kWh/Sm
Column 1
Combustion head pressure drop.
Gas pressure measured at test point 1)(Fig. 23 on page 22), with:
• combustion chamber at 0 mbar
• burner working at maximum output
Column 2
Pressure drop at gas butterfly valve 2)(Fig. 23 on page 22) with
maximum opening: 90°.
21 GB
D722
1 p (mbar)
G 20 G 25 G 20
2.0 3.0 0.1
5.0 7.5 0.2
7.7 11.5 0.3
9.7 14.5 0.4
11.7 17.5 0.5
4.4 6.6 0.3
9.2 13.7 0.4
14.0 20.9 0.6
18.7 27.9 0.8
22.5 33.6 1.2
3
(8.2 Mcal/Sm
3
(7.0 Mcal/Sm
Fig. 22
2 p (mbar)
G 25
0.1
0.3
0.4
0.6
0.7
0.4
0.6
0.9
1.2
1.8
Tab. K
3
)
3
)
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