Fuel Consumption; Fuel Pipe Sizing - Rheem GEN12S Installation And Start-Up Manual

Fuel Consumption

See Figure 7 for estimated fuel supply requirements at half
and full load for both natural gas and LP vapor.
Natural Gas*
1/2 Load Full Load
12kW
102
15kW
140
* = Natural Gas is in cubic feet per hour
** = LP Vapor is in cubic feet per hour
Figure 7 — Fuel Supply Requirements
NPT 10ft 15ft
3/4" 346 293
1" 653 549
Natural Gas (sg=0.65)
Figure 8 — NATURAL GAS (NG) Pipe Size - Gas Flow Chart, in cubic feet per hour
NPT 10ft 15ft
3/4" 277 192
1" 428 360
Liquid Propane (LP) (sg=1.50)
Figure 9 — LIQUID PROPANE (LP) GAS Pipe Size - Gas Flow Chart, in cubic feet per hour
10
LP Vapor**
1/2 Load Full Load
195 41 79
218 66 96
20ft 30ft 40ft
240 192 163
446 360 307
20ft 30ft 40ft
158 126 107
293 236 202

Fuel Pipe Sizing

Figures 8 and 9 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.
50ft 60ft 70ft
145 132 120
274 250 230
50ft 60ft 70ft
95 87 79
180 164 151
80ft 90ft 100ft
113 106 99
211 197 187
80ft 90ft 100ft
74 69 65
139 129 123