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Natural Gas Pipe SizingLongest Length MethodThe Longest Length Method: Add all segments of the piping to each appliance to determine the longest run. In thisexample the run to the water heater is the longest at 85’. On table 4 page 11 the 90’row is the next highest value that will cover the length of this run. We will use this rowto size each segment of the system.Add BTU input for all appliances in the system to determine maximum load.Section A/B 270,000 BTU/hr input. Use table 4 - 90’ row. The 320 value will cover the210,000 load on this segment following this column to the top, 1.25 will be the correctpipe size.Section B/C carries 240,000 BTU/hr after we subtract the Clothes Dryer. In table 4 –90’ row the 320 is still needed to cover this load and following this column to the top1.25 will be the pipe size.Section C/D carries 100,000 BTU/hr after subtracting the Boiler. In table 4 – 90’ row160 is needed to cover this load and following the column to the top 1” will be the pipesize.Each branch will be sized to the Table 4 90’ row. Branch 1, 30,000 BTU/hr will need.5”. Branch 2, 80,000 BTU/hr will need .75”. Branch 3, 45,000 will need .75” pipe.Branch 4 will need .75” pipe.

3Range45,000 BTU/hrinputA-B 30’B-C 20’CB10’C-D 15’12’D20’20’A1Clothes DryerGas Meter30,000 BTU/hrinput24BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinput

Find the longest run from themeterA-B 30’3Range45,000 BTU/hrinput10’B-C 20’CB12’C-D 15’20’D20’A1Clothes DryerGas Meter30,000 BTU/hrinput24BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinputAfter adding the piping sections welearn that the Water Heater is a totalof 85’ from the meter, longer than the75’ run to the Range.

Natural Gas Pipe SizingLongest Length MethodSelect row according to longest run

3Range45,000 BTU/hrinputTotal up all e45,000BC124BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinputClothes Dryer30,000 BTU/hrinputGas Meter4-WaterHeater55,000Total270,000D

Segment A-B Total BTU’s 270,0001.25” pipe3Range45,000 BTU/hrinputBC124BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinputDAClothes DryerGas Meter30,000 BTU/hrinput

Segment B-C Total BTU’s 270,000– Dryer 30,000 240,0001.25” Pipe3Range45,000 BTU/hrinput1.25” pipeBC124BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinputDAClothes DryerGas Meter30,000 BTU/hrinput

Segment C-D 240,000– Boiler 140,000 100,0001” Pipe3Range45,000 BTU/hrinput1.25” pipe1.25” pipeBC124BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinputDAClothes DryerGas Meter30,000 BTU/hrinput

Segment C-D 240,000– Boiler 140,000 100,0001” Pipe3Range45,000 BTU/hrinput1.25” pipe1.25” pipeBC124BoilerWater Heater140,000 BTU/hrinput55,000 BTU/hrinputDAClothes DryerGas Meter30,000 BTU/hrinput

160 is needed to cover this load and following the column to the top 1” will be the pipe size. Each branch will be sized to the Table 4 90’ row. Branch 1, 30,000 BTU/hr will need .5”. Branch 2, 80,000 BTU/hr will need .75”. Branch 3, 45,000 will need .75” pipe. Branch 4 will need .75” pipe. Natural Gas Pipe Sizing Longest Length Method