Fuel Consumption; Natural Gas - Rheem GEN30LP Manuel D'installation

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.
A
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.
NPT 10ft 15ft
3/4" 346 293
1" 653 549
Natural Gas Pipe Size - Gas Flow chart, in cubic feet per hour, specific gravity=0.65
NPT 10ft 15ft
3/4" 277 192
1" 428 360
Liquid Propane (LP) Gas Pipe Size - Gas Flow chart, in cubic feet per hour, specific gravity=1.50
10
B
20ft 30ft 40ft
240 192 163
446 360 307
20ft 30ft 40ft
158 126 107
293 236 202

Fuel Consumption

Estimated fuel supply requirements at half and full load for
natural gas and LP vapor fuels are shown below.

Natural Gas

1/2 Load Full Load
18kW 160 C 293 C
160,000 B 293,000 B
20kW
N/A
N/A
C = Cubic feet per hour
B = BTU's per hour
Physical Properties
Normal Atmospheric State
Boiling Point (in °F):
Initial
End
Heating Value:
BTU per gallon (Net LHV*)
BTU per gallon (gross**)
Cubic feet (gas)
Density***
Weight†
Octane Number:
Research
Motor
* 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".
50ft 60ft 70ft
145 132 120
274 250 230
50ft 60ft 70ft
95 87 79
180 164 151
LP Vapor
1/2 Load Full Load
N/A N/A
N/A N/A
N/A 70.4 C 141.5 C
N/A 176,825 B 353,650 B
LP Vapor Natural
Gas
Gas Gas
-44 -259
-44 -259
83,340 63,310
91,547
2,500 1,000
36.39 57.75
4.24 2.65
110+ 110+
97
80ft 90ft 100ft
113 106 99
211 197 187
80ft 90ft 100ft
74 69 65
139 129 123