Briggs & Stratton 18000 User Manual
Page 12
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BRIGGSandSTRATTON.COM
When the initial test runs are completed, the manometer
is removed and the port is plugged. A typical final fuel
connection assembly is shown here, where (A) is the fuel
supply and (B) goes to the home generator.
Fuel Pipe Sizing
The tables below provide the maximum capacity of pipe in
cubic feet of gas per hour for gas pressures of 0.5 psi or
less and a pressure drop of 0.3 in. water column. Specific
gravity of gas is shown.
Listed values compensate for a nominal amount of
restriction from bends, fittings, etc. If an unusual number of
fittings, bends, or other restrictions are used, please refer to
federal and local codes.
Fuel Consumption
Estimated fuel supply requirements at half and full load for
natural gas and LP vapor fuels are shown below.
B
A
Natural Gas
LP Vapor
/2 Load
Full Load
/2 Load
Full Load
18kW
60 C
293 C
N/A
N/A
60,000 B 293,000 B
N/A
N/A
20kW
N/A
N/A
70.4 C
4.5 C
N/A
N/A
76,825 B 353,650 B
C = Cubic feet per hour
B = BTU’s per hour
NPT
10ft
15ft
20ft
30ft
40ft
50ft
60ft
70ft
80ft
90ft
100ft
3/4”
346
293
240
92
63
45
32
20
3
06
99
”
653
549
446
360
307
274
250
230
2
97
87
Natural Gas Pipe Size - Gas Flow chart, in cubic feet per hour, specific gravity=0.65
NPT
10ft
15ft
20ft
30ft
40ft
50ft
60ft
70ft
80ft
90ft
100ft
3/4”
277
92
58
26
07
95
87
79
74
69
65
”
428
360
293
236
202
80
64
5
39
29
23
Liquid Propane (LP) Gas Pipe Size - Gas Flow chart, in cubic feet per hour, specific gravity=1.50
Physical Properties
LP Vapor
Natural
Gas
Normal Atmospheric State
Gas
Gas
Boiling Point (in °F):
Initial
End
-44
-44
-259
-259
Heating Value:
BTU per gallon (Net LHV*)
BTU per gallon (gross**)
Cubic feet (gas)
83,340
9,547
2,500
63,30
,000
Density***
36.39
57.75
Weight†
4.24
2.65
Octane Number:
Research
Motor
0+
97
0+
*
LHV (Low Heat Value) is the more realistic rating.
** Gross heat value does not consider heat lost in the form of water
during combustion.
*** Density is given in “Cubic Feet of Gas per Gallon of Liquid”.
†
Weight is given in “Pounds per Gallon of Liquid”.