Fuel Consumption; Natural Gas - Rheem GEN27WN Manuel D'installation

The manometer port permits temporary installation of
a manometer to ensure that the engine receives the
correct fuel pressure to operate efficiently throughout its
operating range.
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 generator.
A
Fuel Pipe Sizing
There are numerous on-line or otherwise-published
references for fuel pipe sizing. For example, NFPA 54 -
National Fuel Gas Code, 2006 (Item #: 320-6031-06) is a
common resource. The installer should consider the specific
gravity of gas and compensate for a nominal amount of
restriction from bends, fittings, etc. If an unusual number of
fittings, bends, or other restrictions are used, refer to federal
and local codes for guidance.
12
B

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
27kW 259 C
259,000 B 420,000 B
30kW 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".
LP Vapor
1/2 Load Full Load
420 C N/A
N/A
N/A 92 C 150 C
N/A 228,800 B 373,000 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
N/A
N/A