Thomas & Betts TR - GAS SUPPLY SIZING AND PRESSURE TESTING; Sizing Gas Supply Lines; Pressure Testing Supply Piping; Gas and Electrical Connections

Form RZ-NA-I-TR, Page 18
10-12 (254-305mm) diameter
expansion curve or flexible gas
line MUST BE horizontal with
or above the gas connection.
Install a manual shutoff
valve with 1/8 NPT test
gauge port
10-12
(254-305mm)
diameter
expansion
curve
End
View
Side
View
Allow slack in the electrical cord.
Loop excess and bind loosely with
wire tie or electrical tape.
Grounded Plug-in Cord
Drip
Leg
Capacity of Piping
Cubic Feet per Hour based on 0.3" w.c. Pressure Drop
Specific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)
Length Diameter of Pipe
of 1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
Pipe Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20' 92 56 190 116 350 214 730 445 1100 671 2100 1281
30' 73 45 152 93 285 174 590 360 890 543 1650 1007
40' 63 38 130 79 245 149 500 305 760 464 1450 885
50' 56 34 115 70 215 131 440 268 670 409 1270 775
60' 50 31 105 64 195 119 400 244 610 372 1105 674
70' 46 28 96 59 180 110 370 226 560 342 1050 641
80' 43 26 90 55 170 104 350 214 530 323 990 604
90' 40 24 84 51 160 98 320 195 490 299 930 567
100' 38 23 79 48 150 92 305 186 460 281 870 531
125' 34 21 72 44 130 79 275 168 410 250 780 476
150' 31 19 64 39 120 73 250 153 380 232 710 433
175' 28 17 59 36 110 67 225 137 350 214 650 397
200' 26 16 55 34 100 61 210 128 320 195 610 372
Note: When sizing supply lines, consider possibilities of future expansion and increased requirements.
Refer to National Fuel Gas Code for additional information on line sizing.
Sizing Gas Supply Lines
WARNING
This appliance is equipped for a maximum gas supply pressure of 1/2 pound, 8
ounces, or 14 inches water column.
NOTE: Supply pressure higher than 1/2 pound requires installation of an additional service regulator
external to the unit.
PRESSURE TESTING SUPPLY PIPING
Test Pressures Above 1/2 PSI: Disconnect the heater and manual valve from the gas supply line which is to be
tested. Cap or plug the supply line.
Test Pressures Below 1/2 PSI: Before testing, close the manual valve on the heater.
14. Gas Piping and Pressures (cont'd)
DANGER: Do not install gas piping where it
may be exposed to radiant or convection heat.
See Hazard Levels, page 2.
Figure 23 - Gas and Electrical Connections