Installation
19
20154169
GB
4.9.3
Gas pressure
The is used to calculate manifold pressure taking into account
combustion chamber pressure.
Column 1
Gas manifold pressure measured at test point 1)(Fig. 17), with:
•
Combustion chamber at 0” WC
•
A
= Gas ring 2)(Fig. 12, page 17 - B) adjusted as indicated in
diagram (Fig. 13).
•
B
= Gas ring 1)(Fig. 12, page 17 - B) set to zero.
Calculate the approximate output of the burner thus:
–
subtract the combustion chamber pressure from the gas pres-
sure measured at test point 1)(Fig. 17).
–
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 28/M:
• Maximum output operation
• Natural gas
• Gas ring 2)(Fig. 12, page 17 - B) adjusted as indicated in dia-
gram (Fig. 13, page 17).
• Gas pressure at test point 1)(Fig. 17) = 2.36” WC
• Pressure in combustion chamber = 0.79” WC
2.36 - 0.79 = 1.57” WC
An output of 795 MBtu/hr shown in - RS 28/M corresponds to
1.57” WC pressure, column 1.
This value serves as a rough guide, the exact flow rate must be
measured at the gas meter.
Tab. K
WARNING
The heat output and gas pressure data in the
head refer to operation with gas butterfly valve
fully open (90°).
Fig. 17
D2786
Mbtu/hr
(GCV)
Natural Gas
Δ
p
Combustion head
("WC)
A
B
RS 28/M
624
0.98
0.98
699
1.22
1.30
795
1.57
1.69
891
1.85
2.05
986
2.17
2.28
1078
2.48
2.68
1174
2.76
3.07
1232
2.95
3.58
RS 3
8/M
870
1.02
1.02
979
1.22
1.38
1099
1.46
1.77
1211
1.69
2.28
1327
1.89
2.72
1440
2.72
3.11
1552
2.36
3.54
1665
2.6
4.21
RS 50/M
1090
0.87
0.87
1249
1.14
1.30
1402
1.42
1.61
1552
1.69
2.01
1706
1.97
2.36
1856
2.2
2.76
2006
2.48
3.15
2197
2.83
3.78
Summary of Contents for RS 28/M
Page 2: ...Original instructions...
Page 47: ......
