Appendix - Gas Supply Pressure - Riello RS 50/M MZ Manuel D'entretien

Appendix - Gas supply pressure

C
The table show minimum load losses along the gas supply line depending on the maximum burner output operation.
1
p (mbar)
kW
G 20 G 25
285 2.5 3.7
330 3.3 4.5
380 4.1 5.3
430 4.9 6.1
480 5.8 7.0
530 6.7 8.4
580 7.6 9.9
630 8.5 11.3
The values shown in the tables refer to:
• Natural gas G 20 PCI 9.45 kWh/Sm
• Natural gas G 25 PCI 8.13 kWh/Sm
Column 1
Load loss at combustion head.
Gas pressure measured at the test point 1)(Fig. 39), with:
• Combustion chamber at 0 mbar;
• Burner working at maximum output;
• Combustion head adjusted according to the diagram of
Fig. 16.
Column 2
Load loss at gas butterfly valve 2)(Fig. 39) with maximum open-
ing: 90°.
Column 3
Load loss at train 3)(Fig. 39) including:
• adjustment valve (VR)
• safety valve (VS) (both fully open)
• pressure adjuster (R)
• filter (F)
NOTE
To know the approximate output at which the burner is operating
at its maximum:
- Subtract the combustion chamber pressure from the gas pres-
sure measured at test point 1)(Fig. 39).
- Find, in the table relating to the burner concerned, column 1,
the pressure value closest to the result you want.
- Read off the corresponding output on the left.
Example with natural gas G 20
• Maximum output operation
• Ring nut 2)(Fig. 15) adjusted as in the diagram of (Fig. 16)
• Gas pressure at test point 1)(Fig. 39)
• Pressure in combustion chamber
A pressure of 5.8 mbar, column 1, corresponds in the table to
an output of 480 kW.
This value serves as a rough guide; the effective output must
be measured at the gas meter.
2
p (mbar)
MB-DLE 410
(Rp 1" 1/4)
G 20 G 25 G 20 G 25
0.4 0.5 16.5 22.7
0.5 0.6 21.0 28.4
0.7 0.8 26.0 35.3
0.8 1.0 31.4 42.6
1.0 1.3 37.1
1.3 1.6 43.2
1.5 1.9
1.8 2.2
3 3
(8.2 Mcal/Sm )
3 3
(7.0 Mcal/Sm )
= 8 mbar
= 2.2 mbar
8 - 2.2 = 5.8 mbar
3
p (mbar)
MB-DLE 412 MB-DLE 415
(Rp 1" 1/4) (Rp 1" 1/2)
G 20 G 25 G 20 G 25
8.0 11.1 4.0
10.1 14.2 4.9
13.0 17.7 6.0
15.7 21.4 7.2
18.6 25.6 8.5 11.2
21.8 30.1 9.7 12.9
25.2 34.5 11.0 14.6
28.8 39.1 12.4 16.4
NOTE
To know the required gas pressure at test point 1)(Fig. 39),
set the MAX output required from the burner operation:
- Find the nearest output value in the table for the burner in
question.
- Read, on the right column (1) the socket pressure 1)(Fig. 39).
- Add this value to the estimated pressure in the combustion
chamber.
Example with natural gas G 20
• Required burner maximum output operation: 480 kW
• Ring nut 2)(Fig. 15) adjusted as in the diagram of (Fig. 16)
• Gas pressure at output of 480 kW
• Pressure in combustion chamber
pressure required at test point 1)(Fig. 39).
35
GB
MB-DLE 420 MBC-1200-SE
(Rp 2")
G 20 G 25 G 20
5.3 3.2 3.4 3.4
6.6 3.2 4.2 3.5
8.0 3.8 5.1 3.7
9.6 4.6 6.2 3.9
5.4 7.3 4.1
6.2 8.6 4.3
7.2 9.8 4.5
8.2 11.1 4.8
5.8 + 2.2
D934
(Rp 2")
G 25
3.6
3.8
4.0
4.3
4.6
4.9
5.2
5.5
= 5.8 mbar
= 2.2 mbar
= 8 mbar
Fig. 39
6463