3
4.3
COMBUSTION CHAMBER SIZING
Table 1. Combustion Chamber Recommended Dimensions
Gas Input
Width
Length
Gas Input
Width
Length
MBTU/HR
Inches
Inches
MBTU/HR
Inches
Inches
450
15
20
1260
23
33
600
16
23
1500
25
38
700
17
25
1800
26
40
850
18
26
2200
28
42
4.4
Whichever method of mounting is chosen, the burner blast tube must be recessed into the front wall
surface from 0” to 1/2”.
NOTE: Serious Damage To The Burner May Result If The Blast Tube is
Extended Into The Combustion Chamber.
4.5
Secure the burner to the heat exchanger or boiler, using the burner-mounting flange. A tight seal
between the mounting flange and the front plate should be made using the factory-furnished gasket or
ceramic non-asbestos fiber rope
.
5
GAS PIPING
5.1
Contact you local gas service company to ensure that adequate gas service is available and to review
applicable installation codes for your area. All gas piping installations must be in accordance with NFPA
54, National Fuel Gas Code, Definitions and General Field Recommendations, CGA 3.0, Canadian
Natural Gas Installation Code CAN/CGA B149.1 or Propane Installation Code, CGA B 149.2.
5.2
Size the main gas line in accordance with Table 2. The figures shown are for straight lengths of pipe at
0.2” W.C. pressure drop, which is considered normal for low-pressure systems. Note that fittings such as
elbows and tees will add to the pipe pressure drop.
Table 2 - Gas Piping Pressure Drop Data
EQUIVALENT LENGTH OF STRAIGHT PIPE IN FEET
20
30
40
50
60
80
100
150
200
Pipe Size In Inches
CFH GAS WITH .2” PRESSURE DROP
1”
300
250
210
190
180
150
135
110
75
1-1/4” 520
425
360
325
300
260
230
190
165
1-1/2” 800
690
560
500
480
410
370
300
260
2”
1700
1400
1200
1100
1000
850
750
600
540
2-1/2” 3000
2500
2100
1900
1800
1550
1375
1100
950
EQUIVALENT LENGTHS OF STANDARD PIPE IN FEET FOR LISTED FITTINGS
Fitting Type
1”
1-1/4” 1½”
2”
2-1/2” Nominal Pipe Size In Inches
Std. Tee
5.5
7.5
9.0
12.0
13.5
Std. Elbow
2.7
3.7
4.5
5.5
6.1
5.3
Refer to Figure 3 for details of standard gas piping. (Also refer to any additional piping diagrams supplied
for this specific unit.)
5.4
Mount leakage test and main gas cocks, main automatic gas valve or combination gas valve/pressure
regulator, and auxiliary valves (if required and not factory mounted) per piping diagram or Figure 3 on
page 4.
