Installation
23
20052068
GB
4.10.3 Gas pressure
The diagram (Fig. 21) showS minimum load losses at combustion
head depending on the maximum burner output operation with nat-
ural gas (G 20).
Gas pressure is measured at the test point 1)(Fig. 22), with:
•
Combustion chamber at 0 mbar
•
Burner working at maximum output
•
Ring nut 2)(Fig. 15) adjusted as in the diagram of Fig. 14
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. 22);
–
find, in the diagram (Fig. 21) the pressure value closest to the
result you want;
–
read the corresponding output on the left.
Example RS 190/E
•
Maximum output operation
•
Ring nut 2)(Fig. 15) adjusted as in the diagram of Fig. 14
•
Gas pressure at test point 1)(Fig. 22)
=
6 “wc
•
Pressure in combustion chamber
=
1.2 “wc
6.0 - 1.2
=
4.8 “wc
A maximum output of 7800 MBtu/hr corresponds to 4.8 “wc pres-
sure. This value serves as a rough guide; the effective output must
be measured at the gas meter.
NOTE
To know the required gas pressure at test point 1)(Fig. 22), set the
maximum output required from the burner operation, then:
–
find the nearest output value in the table for the burner in ques-
tion.
–
read, on the diagram (Fig. 21), the pressure test point 1)
(Fig. 22);
–
add this value to the estimated pressure in the combustion
chamber.
Example RS 190/E
•
Maximum output required: 7800 MBtu/hr
•
Ring nut 2)(Fig. 15) adjusted as in the diagram of Fig. 14
•
Gas pressure at output of 7800 MBtu/hr
=
4.8 “wc
•
Pressure in combustion chamber
=
1.2 “wc
4.8 + 1.2
=
6.0 “wc
pressure required at pressure test point 1)(Fig. 22).
∆
p “WC gas butterfly 2)(Fig. 22)
Tab. E
Fig. 21
Burner output operation
D3190
∆
p
(
“W
C
)
MBtu/hr
kW
∆∆∆∆
p2 “WC
4848
1421
0.5
5302
1554
0.6
5681
1665
0.7
6060
1776
0.8
6438
1887
0.9
6817
1998
1.1
7196
2109
1.2
7575
2220
1.3
7953
2331
1.4
8673
2542
1.7
Fig. 22
1
2
D2441
