Written by Frank Erickson

Trac-pipe

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.

Propane pipe fittings

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!

 

Approximate BTU Ratings for Appliances

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

 

Capacity of Pipe (BTU x 1000) at ½ psi Copper

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

 

Capacity of Pipe (BTU x 1000) at ½ psi Iron Pipe

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

 



 

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Salesman Frank Erickson

Frank Erickson

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