Gas Trains - Beckett CG10 Manual

Section: Connect Gas Piping
Figure 7. Typical Gas Piping Layout
METER
REGULATOR PG U
GAS UTILITY PIPING
Table 1. Gas supply piping capacity
Schedule 40 metallic pipe with 0.50 psi or less inlet pressure and 0.30" W.C. pressure drop
Maximum capacity in cubic feet of gas per hour (CFH). Natural gas with 0.60 specifi c gravity. Pipe size (inches) IPS
Pipe Length (ft.) 0.75"
10 278
20 190
30 152
40 130
50 115
60 105
70
80
90
100
125
150
175
200
Install a Drip Leg in Gas
Supply Piping
Foreign matter could lodge in gas valve cutoff seals,
resulting in gas leak-through, explosion or fi re.
Install a full-size drip leg or dirt pocket in the piping directly
ahead of the main shutoff valve to capture foreign matter.

Gas Trains

Gas Leaks and Exposion
Hazards
Provide Over-pressure Protection
CSD-1 requires that if gas pressure entering the
building exceeds the rating of any gas train component
an overpressure protection device must be installed.
10
DRIP LEG
S
(IF USED)
FACILITY PIPING
1.0" 1.25"
520 1050
350 730
285 590
245 500
215 440
195 400
96 180 370
90 170 350
84 160 320
79 150 305
72 130 275
64 120 250
59 110 225
55 100 210
LGPS
U TC
MSC SSOV1 2PRV
GAS TRAIN
1.5" 2.0"
1600 3050
1100 2100
800 1650
760 1450
670 1270
610 1150
560 1050
530 990
490 930
460 870
410 780
380 710
350 650
320 610
Standard – An Underwriters Laboratories (UL) listed
gas train is standard for the CG10 gas burner. This
confi guration also meets CSD-1 requirements. See
Figure 8 for typical component layout.
Propane (LP) – When the correct propane restrictor
is added to a burner's gas pipe assembly it changes
the burner's gas pressure drop so that the propane
pressure drop is equal to the natural gas pressure drop
of the same BTU fi ring rate. That is why the Manifold
to Furnace Pressure Drop curves of Figures 12 and
13 are correct for both propane and natural gas. That
is also why a gas train adjusted for the burner's natural
gas requirements will be correctly adjusted for its
propane requirements. R. W. Beckett provides the same
pressure regulating safety shutoff valve in the gas train
(usually a Honeywell V4944B) for both natural gas and
propane. The valve is marked for natural gas due to
its primary usage in a pressure range normally used
ABBREV. ITEM DESCRIPTION
HGPS HIGH GAS PRESSURE SWITCH
LGPS LOW GAS PRESSURE SWITCH
MSC MAIN SHUTOFF COCK
MLTC MAIN LEAK TEST COCK
PG PRESSURE GAUGE
S STRAINER
SSOV1 SAFETY SHUTOFF VALVE #1
TC TEST COCK
U UNION
2PRV TWO POSITION REGULATING VALVE
HGPS
BURNER
TC
TC MLTC U
BURNER
2.5" 3.0"
4800 8500
3300 5900
2700 4700
2300 4100
2000 3600
1850 3250
1700 3000
1600 2800
1500 2600
1400 2500
1250 2200
1130 2000
1050 1850
980 1700
4.0"
17500
12000
9700
8300
7400
6800
6200
5800
5400
5100
4500
4100
3800
3500