Pilot - Gas Train Connection - Riello DB 20 SE FGR TC FS1 FB A0 T150 Installation, Use And Maintenance Instructions

Column 1
Combustion head pressure drop.
Gas pressure measured at test point 1)(Fig. 18), with:
• combustion chamber at 0 mbar;
• burner working at maximum modulating output;
• combustion head set as on page 23.
Column 2
Pressure loss at gas butterfly valve 2)(Fig. 18) with maximum
opening: 90°.
To calculate the approximate output at which the burner oper-
ates:
– subtract the pressure in combustion chamber from the gas
pressure measured at test point 1) (Fig. 18);
– find, in Tab. H related to the burner concerned, the pressure
value closest to the result of the subtraction;
– Read off the corresponding output on the left.
Example with natural gas G20:
Operation at maximum modulating output
Gas pressure at test point 1)(Fig. 18)
Pressure in combustion chamber
29.3 - 5
A pressure of 24.3 mbar, column 1, corresponds in Tab. H to an
output of 12,000 kW.
This value serves as a rough guide; the effective output must be
measured at the gas meter.
To calculate the required gas pressure at test point 1) (Fig. 18),
set the maximum modulating output required from the burner op-
eration:
– find the nearest output value in Tab. H for the burner in ques-
tion.
– read, on the right (column 1), the pressure at the test point 1)
(Fig. 18).
– Add this value to the estimated pressure in combustion
chamber.
Example with natural gas G20:
Operation at maximum modulating output
Gas pressure at an output of 12,000 kW =
Pressure in combustion chamber
24.3 + 5
pressure required at test point 1)(Fig. 18).
20136081
Installation
5.9.6
The burner is fitted with a dedicated gas train that is fixed to the
pipe coupling.
 It should be connected to the main train downstream the fil-
ter or the pressure adjuster (depending on configuration).
WARNING
= 29.3 mbar
= 5 mbar
= 24.3 mbar
24.3 mbar
= 5 mbar
= 29.3 mbar
20 GB

Pilot - gas train connection

Supply pressure 68 ÷ 500 mbar.