PART I: INSTALLATION
9
How to read the burner “Performance curve”
To check if the burner is suitable for the boiler to which it must be instal-
lled, the following parameters are needed:
furnace input, in kW or kcal/h (kW = kcal/h/860);
backpressure (data are available on the boiler ID plate or in the
user’s manual).
Example:
Furnace input: 600kW
Backpressure: 4 mbar
In the “Performance curve” diagram, draw a vertical line matching the
furnace input value and an horizontal line matching the backpressure
value. The burner is suitable if the intersection point A is inside the per-
formance curve.
Data are referred to standard conditions: atmospheric pressure at 1013
mbar, ambient temperature at 15° C.
Checking the proper gas train size
Performance curves
To check the proper gas train size, it is necessary to the available
gas pressure value upstream the burner’s gas valve. Then subtract
the backpressure. The result is called
pgas.
Draw a vertical line
matching the furnace input value (600kW, in the example), quoted
on the x-axis, as far as intercepitng the network pressure curve,
according to the installed gas train (DN65, in the example). From the
interception point, draw an horizontal line as far as matching, on the
y-axis, the value of pressure necessary to get the requested furnace
input. This value must be lower or equal to the
pgas
value, calcula-
ted before.
BACK PRESSURE
IN
COMBUSTION
CH
AMBER
mbar
NG550 - LG550 Single stage
kW
NG550 - LG550 Double-stage/Progressive
kW
Campo di lavoro bruciatori
Tipo P60 Mod. M-xx.x.IT.A.0.50 - M-.xx.x.IT.A.0.65
-1
0
1
2
3
4
5
6
7
8
100
200
300
400
500
600
700
800
900
Potenza kW
Contropressione in camera di
combustione mbar
A
ba
ckpr
essu
re in
co
m
bu
st
ion
ch
am
b
e
r
(m
b
ar
)
Power kW
0
5
10
15
20
25
100
200
300
400
500
600
700
800
900
Potenza / Output (kW)
Minima pressione gas in
rete / Minimum inlet gas
pressure (mbar)
Rp 2" (50)
DN65
Power kW
minimu
m
ga
s pre
ssur
e
in
the ne
twork mbar
DN65
0
1
2
3
4
5
6
7
8
9
10
200
250
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350
400
450
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550
600
650
-1
0
1
2
3
4
5
6
7
8
9
10
100 150 200 250 300 350 400 450 500 550 600 650
