Written by Frank Erickson
It is important when installing a gas line that you size it correctly for the application. When sizing gas piping systems certain factors must be considered. Piping must be sized to supply enough gas for all appliances to operate at the same time. To determine this you must add the BTUs of all of the appliances in the system and take into consideration the type of metal the pipe is made from. As you can see below there is a chart for copper tubing size and a chart for iron pipe size with the BTU ratings for the length and diameter of the line.
You should also consider that the customer may want to add appliances at a later date. Gas piping should be sized in accordance with the tables in the Standard Gas Code or by other engineering methods approved by local Authority Having Jurisdiction. When sizing the gas line make sure you add 5 feet per elbow to the total length. If the gas line is undersized the appliances will operate inefficiently and could lead to equipment failure and sooting. If you are adding appliances to an existing system and are finding that the line size may be too small, install a 2 PSI regulator with Maxitrol regulators at the appliance.
Remember to pressure and leak test your systems prior to putting into service. BE SAFE!
| Appliance | Input BTU per Hour (approx.) | |
| Range, free standing oven - Domestic | 65,000 | |
| Built-in oven or broiler unit - Domestic | 25,000 | |
| Built-in counter top unit - Domestic | 40,000 | |
| Water Heater, Automatic instantaneous | ||
| Capacity | 2 gallons per minute | 142,800 |
| 4 gallons per minute | 285,000 | |
| 6 gallons per minute | 428,400 | |
| Refrigerator | 3,000 | |
| Clothes Dryer - Domestic | 35,000 | |
| Gas Light | 2,500 | |
| Gas Logs | 30,000 | |
| Nominal Pipe Size COPPER (in) | Pipe Length(ft.) | |||
| 10 | 20 | 40 | 80 | |
| 1/4 (3/8) | 35 | 25 | 17 | 12 |
| 3/8 (1/2) | 75 | 50 | 35 | 25 |
| 1/2 (5/8) | 150 | 105 | 70 | 50 |
| 5/8 (3/4) | 265 | 180 | 125 | 85 |
| 3/4 (7/8) | 380 | 260 | 180 | 120 |
| 1 (1 1/8) | 805 | 555 | 380 | 260 |
| 1 1/4 (1 3/8) | 1450 | 995 | 685 | 470 |
| Pipe Size (in) | Pipe Length(ft.) | |||||
| 10 | 20 | 40 | 80 | 150 | 300 | |
| 1/2 | 235 | 160 | 110 | 75 | 55 | 35 |
| 3/4 | 490 | 340 | 230 | 160 | 115 | 80 |
| 1 | 925 | 640 | 440 | 300 | 215 | 145 |
| 1 1/4 | 1900 | 1305 | 900 | 620 | 440 | 300 |
| 1 1/2 | 2850 | 1960 | 1345 | 925 | 660 | 450 |
| 2 | 5490 | 3770 | 2590 | 1780 | 1270 | 870 |
| 2 1/2 | 8740 | 6010 | 4130 | 2840 | 2020 | 1390 |
| 3 | 15455 | 10620 | 7300 | 5020 | 3570 | 2450 |
| 4 | 31525 | 21670 | 14890 | 10230 | 7280 | 5010 |
| 5 | 57030 | 39200 | 26940 | 18520 | 13180 | 9060 |
| 6 | 92350 | 63470 | 43620 | 29980 | 21340 | 14665 |
| 8 | 189750 | 130410 | 89630 | 61600 | 43840 | 30135 |
Like this Article? Why not Share!
