5.11.3 Gas train
Approved according to standard EN 676 and provided separately
from the burner.
5.11.4 Gas train installation
Disconnect the electrical power using the 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 gas train is pre-arranged to be connected to the burner at the
flange 2)(Fig. 20).
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Installation
5.11.5 Gas pressure
Tab. J indicates the pressure drops of the combustion head and
gas butterfly valve, on the basis of the burner operating output.
kW
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
10500
11000
11500
12000
12500
–
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. 20), with:
•
combustion chamber at 0 mbar;
•
burner working at maximum modulating output;
•
combustion head set as on page 18.
Column 2
Pressure loss at gas butterfly valve 2)(Fig. 20) with maximum
opening: 90°.
To calculate the approximate output at which the burner oper-
Fig. 20
ates:
–
subtract the pressure in combustion chamber from the gas
pressure measured at test point 1)(Fig. 20).
–
Find, in Tab. J related to the burner concerned, the pressure
value closest to the result of the subtraction.
Read the corresponding output on the left.
20
GB
1 ∆ p (mbar)
G 20
G 25
G 20
16.0
23.2
1.8
19.1
27.6
2.2
22.1
32.0
2.6
25.2
36.3
3.1
28.9
41.6
3.6
32.9
47.2
4.1
36.9
52.7
4.7
41.5
59.4
5.3
46.4
66.3
5.9
51.2
73.3
6.6
25.9
12.3
2.7
30.8
14.6
3.2
36.2
17.2
3.8
42.0
19.9
4.4
48.2
22.9
5.0
54.8
26.0
5.7
61.9
29.4
6.5
69.4
32.9
7.3
77.3
36.7
8.1
85.6
40.7
9.0
94.4
44.8
9.9
103.6
49.2
10.8
113.2
53.8
11.8
123.3
58.6
12.9
133.8
63.5
14.0
3
(8.2 Mcal/Sm
3
(7.0 Mcal/Sm
2 ∆ p (mbar)
G 25
2.7
3.3
3.9
4.6
5.3
6.1
7.0
7.9
8.8
9.8
1.1
1.3
1.6
1.8
2.1
2.4
2.7
3.0
3.4
3.7
4.1
4.5
4.9
5.4
5.8
Tab. J
3
)
3
)