Gas Piping - Rheem CRTGH-95X Series Use And Care Manual

Gas Piping

Pipe-SizingProcedure–Example
Thegassupplymustbecapableofhandlingtheentire
gasloadatthelocation.Gaslinesizingisbasedon
gastype,thepressuredropinthesystem,thegas
pressuresupplied,andgaslinetype.Forgaspipe
sizingintheUnitedStates,refertotheNationalFuel
GasCode,NFPA54.ForCanadiangaspipesizing,
refertotheNaturalGasandPropaneInstallationCode
CAN/CSAB149.1.Theinformationbelowisprovidedas
anexample.Theappropriatetablefromtheapplicable
codemustbeused.
1.Determinethecubicfeetperhourofgasrequired
bydividingthegasinput(ontheratingplate)bythe
heatingvalueofthegas(availablefromthelocal
gascompany).Thegasinputneedstoincludeall
gasproductsatthelocationandthemaximumBTU
usageatfullloadwhenallgasproductsareinuse.
GasInputof
CubicFeetWaterHeater(BTU/HR)
PerHour(CFH)=HeatingValueofGas(BTU/FT
Pipe-SizingTable–NaturalGas
Schedule40MetallicPipe
InletPressure:Lessthan2psi(55inchesW.C.)
PressureDrop:0.3inchesW.C.
SpecificGravity:0.60
(Capacityincubicfeetperhour)
PipeSize(inches)
Length
3/4 1
10 273 514
20 188 353
30 151 284
40 129 243
50 114 215
60 104 195
70 95 179
80 89 167
90 83 157
100 79 148
125 70 131
150 63 119
175 58 109
200 54 102
Thisisanexample,inUS,refertocurrentNationalFuelGas
Code,NFPA54forcorrectpipesizingchart,andinCanada,
refertocurrentCAN/CSAB149.1.
INSTALLATION INSTRUCTIONS
2.Usethetableforyourgastypetofindthepipesize
requiredforyourcubicfeetperhourofgasand
yourpipelength.
Example:Theheatingvalueofpropanegasfor
yourlocationis2500BTU/FT
tanklesswaterheateris199,900BTU/HR.Additional
appliancesatthelocationrequire75,000BTU/HR.
Therefore,thecubicfeetperhour=
(199,900+75,000)/2500=109FT
pipelengthis100ft.,thenthe3/4-inchpipesize
capableofsupplying197FT
beadequate.
)
3
Length
11/4 11/2
1060 1580
726 1090
583 873
499 747
442 662
400 600
368 552
343 514
322 482
304 455
269 403
244 366
224 336
209 313
3
/HRofpropanegaswill
3
Pipe-SizingTable–PropaneGas
Schedule40MetallicPipe
InletPressure:11.0inchesW.C.
PressureDrop:0.5inchesW.C.
SpecificGravity:1.50
(Capacityincubicfeetperhour)
PipeSize(inches)
1/2 3/4
10 291 608
20 200 418
30 160 336
40 137 287
50 122 255
60 110 231
80 101 212
100 94 197
125 89 185
150 84 175
175 74 155
200 67 140
.Thegasinputofthe
/HR.Ifthe
3
1 11/4
1150 2350
787 1620
632 1300
541 1110
480 985
434 892
400 821
372 763
349 716
330 677
292 600
265 543
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