Gas Supply Pipe Looping and Sizing
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6
7
1
Gas Furnace (120,000 Btu/hr)
2
Gas Water Heaters (400,000 Btu/hr each)
3
Gas Space Heaters (70,000 Btu/hr each)
4
19 ft. (5.8 m)
5
25 ft. (7.6 m)
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Main Regulator
7
Gas Meter
8
Pressure Regulator (If required)
9
Gas Tumblers (120,000 Btu/hr each)
10
Gas Line Pressure Tap
11
1 in. (25.4 mm) Gas Pipe Loop
12
NOTE: Minimum Pipe Size is 1/2 in. (12.7 mm)
13
Shut-Off Valves
SAMPLE CALCULATIONS:
Equivalent length = Total length of main gas supply pipe to the far end of the tumblers.
= 25 ft. + 19 ft. (7.6 m + 5.8 m) gas supply pipe
= 44 ft. (13.4 m) Total Gas Line
Total Btu/hr
= The sum of the Btu/hr of all tumblers being fed by the main gas supply pipe.
= 9 x 120,000
= 1,080,000 Btu/hr
Using Table 9, the main supply pipe diameter should be 2 in. (51 mm).
IMPORTANT: Gas loop piping must be installed as illustrated to equalize gas pressure for all tumblers connected to
single gas service. Other gas using appliances should be connected upstream from loop.
70268201
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13
Figure 14
Gas Requirements
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9
4
12
10
11
T494I
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