Riello 46662X Installation, Use And Maintenance Instructions page 30

2.6 Gas side pressure drop
D3978
100
90
80
70
60
50
mbar
40
30
20
10
0 2000
Fig. 8
D3979
18
16
14
12
10
mbar
8
6
4
2
Fig. 9
8
Head pressure drop
4000 6000 8000
Pb (Burner output)
Butterfly valve pressure drop
Pb (Burner output)
CHAPTER
10000 12000 14000
[kW] KW
KW
[kW]
2
Burner description
Gas pressure on the basis of the
maximum output developed by
the burner is given by the curves
in Fig. 8.
It represents the pressure drop
in the combustion head.
Natural gas G 20 - Net calorific
3
value = 10 kWh/Nm
The curves were taken in the fol-
lowing conditions:
• pressure measured at the test
point on the pressure switch
downstream from the gas but-
terfly valve;
• combustion chamber at 0
mbar;
• burner working at full output.
The pressure drop of the com-
pletely open butterfly valve is
given in Fig. 9.