Gas Pressure - Riello RS/M Series Installation, Use And Maintenance Instructions

4.9.3

Gas pressure

The Tab. G is used to calculate manifold pressure taking into ac-
count combustion chamber pressure.
Column 1
Gas manifold pressure measured at test point 1)(Fig. 19), with:
• Combustion chamber at 0 "WC
• Burner operating at maximum output
• Gas ring 2)(Fig. 11, page 17) adjusted as indicated in diagram
(Fig. 12, page 17).
Column 2
• pressure loss at gas butterfly valve
Calculate the approximate maximum output of the burner as fol-
lows:
 subtract the combustion chamber pressure from the gas pres-
sure measured at test point 1)(Fig. 19).
 Find the nearest pressure value to your result in column 1 of
the table for the burner in question.
 Read off the corresponding output on the left.
Example - RS 100/M:
• Maximum output operation
• Natural gas
• Gas ring Fig. 11, page 17 adjusted as indicated in diagram
(Fig. 12)
• Gas pressure at test point 1)(Fig. 19)
• Pressure in combustion chamber
3.15 - 1.18
A maximum output of 3125 MBtu/hr shown in Tab. G corresponds
to 1.97 "WC pressure, column 1.
This value serves as a rough guide, the effective delivery must be
measured at the gas meter.
The heat output and gas pressure data in the
head refer to operation with gas butterfly valve
fully open (90°).
WARNING
Installation
Model
= 3.15 "WC
= 1.18 "WC
= 1.97 "WC
21 GB
MBtu/hr kW
1761 516
1952 572
2139 627
2330 683
2518 738
2709 794
2897 849
3084 904
2631 771
2880 844
3125 916
3371 988
3617 1060
3862 1132
4108 1204
4405 1291
3521 1032
3825 1121
4129 1210
4432 1299
4736 1388
5036 1476
5340 1565
5545 1625
20161046
p (" WC)
1 2
1.65 0.2
1.89 0.3
2.20 0.4
2.52 0.4
2.87 0.5
3.27 0.5
3.66 0.5
4.06 0.6
1.46 0.3
1.65 0.4
1.97 0.4
2.28 0.5
2.56 0.5
2.87 0.7
3.27 0.7
3.66 0.9
1.50 0.6
1.77 0.7
2.01 0.9
2.28 1.0
2.56 1.1
2.83 1.3
3.11 1.4
3.20 1.6
Tab. G
1
2
Fig. 19
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