New Gas Lines Part 1 of 2

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Running new pipe lines allows you to enjoy the practical and cost-savings benefits of natural gas in all areas of your home.


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Do you want to enjoy the efficiency and control of cooking on a gas range, but your kitchen only supports an electric model? Or perhaps you’ve been meaning to move the range to improve the workflow. Would you like to add a supplementary gas water heater closer to your master bath? Are you planning to add a permanent heat source in your garage? Or do you simply want to save money by converting from electricity to gas fuel for a few of your major appliances? Any of these projects is within your grasp as long as your home already has natural gas service. You simply need to install a new branch gas line.
Installing a gas line isn’t difficult, but it is dangerous and in many areas you simply aren’t allowed to do it yourself.
If you choose to proceed with the new line installation, begin by mapping out where the new line will run and calculating what lengths of pipe and which fittings you will need. Begin at the supply pipe you’ll be tying into and work forward. Also check with your local building department to find out which types of pipe are allowed and which types they recommend for your job.
The number of gas appliances a branch line can support is limited by the diameter of the branch and length of runs, so you’ll need to know exactly which other appliances are serviced by the branch you’re tying into and how much fuel they consume (see Gas Consumption of Household Appliances). You will need to obtain a permit and have your work inspected, so it’s good to involve the inspections department up front.
Notes for Installing Gas Lines:

• In most areas, a shut-off valve (usually a ball valve) must be accessible within 3 ft. of the appliance and in the same room
• If you are relocating a line and cannot remove the existing branch supply line because of limited access, you will need to cap the gas stub-out.
• If you live in an area that allows flexible copper or flexible stainless steel connectors you will have more room for error in your measurements. If you must connect only using rigid black pipe, you may need to have some pipe lengths cut and threaded to fit.
• Most areas allow Type K and Type L copper tubing for installation in an LP gas or natural gas line. But always check with your local building department.
• Never use standard plumbing fittings with gas pipe. Use only gas-rated, cast brass stopcocks for smaller pipe (less than 3" dia.) and use gas-rated globe or gate valves for larger pipe.
Gas Consumption of Household Appliances50-gallon water heater (Avg. 50,000 Btu’s per hour and 50 cu. ft. gas consumption per hour*
Furnace (Avg. 200,000 Btu’s per hour and 200 cu. Ft. gas consumption per hour*
Clothes dryer (Avg. 35,000 Btu’s per hour and 35 cu. Ft. gas consumption per hour*
Range/oven (Avg. 65,000 Btu’s per hour and 65 cu. ft. gas consumption per hour*
*Based on output rate of 1,000 Btu per cubic foot of fuel per hour. Your actual rate will likely differ. Check with your energy company.

Determine the flow rate for a branch line by adding the gas consumption per hour (use above data only if specific information is not printed on your appliance label) of each appliance. Although appliances may not run concurrently, it is advisable to select pipe size based on 100% flow rate. Note that distance traveled also plays an important role in selecting pipe size diameter (1⁄2", 3⁄4", 1", 11⁄4", or 11⁄2").
From: The Complete Guide to Plumbing, 978-1-58923-378-2

What You'll Need


Adjustable wrench


Adjustable wrench


Step 1

Pipe Run Pitch

Horizontal pipe runs must be pitched downward slightly, either by using progressively thicker shims between pipe and the attachment surface, or by making progressively deeper cutouts in a support member, or drilling access holes that become progressively lower in joists.

Step 2

Tips for Running Gas Pipe

Horizontal pipe runs should terminate in a drip nipple that drops from the end to capture moisture and impurities.

Step 3

Tips for Running Gas Pipe

Make branch connections at the side or top of the pipe you are tying into. If you need to drop down or up, run a branch line at least 6" long straight out from the side of the pipe and then drop down or go up with a 90° union.

Step 4

Tips for Running Gas Pipe

Protect pipes running in enclosed wall cavities with steel protector plates to stop nails or screws before they reach the pipe. Pipes in enclosed walls must be at least 1⁄2" in diameter.

Step 5

How to Install a Branch Gas Line

Begin layout at the end of the run. Pull the appliance away from the wall slightly in the new location and mark the most convenient spot for the new gas line to enter the room. The easiest installation is up through the floor. Drill a hole through the floor and thread a wire through the hole to mark the location of the proposed gas line.

Step 6

How to Install a Branch Gas Line

From the basement, locate the wire and determine whether the placement is feasible. Adjust the placement to work around joists or other supply lines if necessary. Drill a 1" hole up through the floor.

Step 7

How to Install a Branch Gas Line

Turn off the gas at the gas meter, using an adjustable wrench. The valve does not have a stop, so it can rotate indefinitely. The gas is off when the bar is perpendicular
to the pipe.

Step 8

How to Install a Branch Gas Line

Disconnect the existing appliance. If a flexible stainless steel connector was used, discard it, as they can only be installed once. Remove the gas stub-out or flexible copper
line back to the supply line.

Step 9

How to Install a Branch Gas Line

Begin fitting the new pipe. Apply pipe compound or gas-rate, yellow PTFE tape to all male threads. Hand tighten each joint, then tighten each pipe and fitting at least one turn before moving on to the next section. You may need to tighten more than one turn to get the proper alignment. Wipe any excess joint compound from the exposed threads.

Step 10

How to Install a Branch Gas Line

Support pipe runs with pipe hangers rated for use with your pipe material. Make sure that the line has a slight downward slope from the source toward the appliance.



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