How To Install Yellow Gas Line

Download Article

Installing a gas line is probably not a task to take on as your first do-it-yourself project. The risks of making a mistake outweigh the costs of a professional. However, experienced do-it-yourselfers can install a gas line as safely as a professional. Despite the narrow margin for error, the individual steps are no more demanding than plumbing or electrical work.

Be sure to check local regulations - for example in the UK, it is illegal to modify a gas installation without a professional certificate of competence and doing so could result in prosecution, a fine or even imprisonment.

Steps

1

Turn off the gas to your house. The valve will be at your gas meter on the side of your house and should shut off entirely with a quarter-turn. A position perpendicular to the pipe indicates a closed valve, but you should double-check by confirming that the meter is no longer moving when a appliance is using gas.^[1]
2

Buy the right gas pipes and fittings for the job. Most domestic gas lines use 1/2-inch (1.27 cm) through 1 1/2 inch (3.81 cm) black pipe, while large commercial projects sometimes use larger fittings up to 8 inch. from 1/2" to 1 1/2"pipe the face of a fitting to face of another fitting you add 3/4".^[2]

Advertisement
3
Extend your existing gas line by fitting the valves and pipe lengths you need to add a gas line that will reach your new appliance.
- Coat the threads of the pipe ends using pipe dope.^[3] This is essential to establishing an airtight fit. Never use tape, including Teflon tape; it can come loose inside the pipe and can clog the line.
- You can make your job easier by assembling some lengths of your gas line in your garage or shop, then moving them to the crawl space or wall where your gas lines run. Be wary of 90-degree bends if you do this; it makes turning the pipe to tighten it more difficult.
4

Use a flexible pipe to connect the end of your new gas line to the appliance. (This is not required unless in earthquake prone area/zone.) Follow instructions supplied with flex connectors.^[4]
5

Test your line is airtight. Spread a mixture of 1:1 water and dish liquid over each seam in your gas line. If bubbles appear, you have a leak. Try tightening the joint some more until you can not tighten anymore. If still leaks, undo, check threads, and reapply pipe dope and tighten again. If the leak still appears, change the pipe and fitting.^[5]
6

Turn the gas back on by returning the valve to parallel to the incoming pipe. Test your appliance to ensure the gas is flowing properly.

Advertisement

Add New Question

Question

Is there a difference between black pipe and galvanized pipe? Can galvanized pipe be used for gas lines?

Galvanized pipe has a coating which can strip off, resulting in flakes travelling through the pipe and getting stuck in orifices. Municipal or building codes will usually require that galvanized pipe can never be used for gas.
Question

How deep do I have to go underground?

Check with your local gas company. This is a dangerous operation, so you need the experts to help here and stay within the law.
Question

Can I use copper pipe for my gas line?

No. Your swing joint would not be able to move with any shifting, due to solder holding your pipes into place.
Question

How do I thread a pipe that has to be shortened?

There are special tools (dies, vices) that are needed for this. Some tool stores will cut to size if you buy the pipe from them. Or, you can rent the tools and do it yourself. Ask the retailer to assist you with a demonstration.
Question

Why is gas leaking from my gas regulator?

You need to urgently call the gas supplier, and in the meantime, the gas should be turned off and the premises evacuated.
Question

Are unions okay to use on gas lines?

Yes, as long as the union is also rated for gas line plumbing usage. Be sure to test for leaks in the union using a soapy water test, or an electronic gas line leak tester (don't use a flame, or assume you will hear or smell a leak).
Question

I noticed that you suggest using the pipe tape -- I learned that pipe tape is not safe for gas lines as it can crack and shred into the gas pipes causing blockage. I was told to use the pipe goop, is that right?

You're right, pipe tape is not for use on gas lines. These are generally galvanized steel pipes and use a goop for sealing the joints.
Question

I have a 1/2" gas line to my new stove, but the shut-off valve has a 5/8" connector on it. What's the solution?

You would use a 5/8" to 1/2" adapter, and then you would need a small 1/2" piece of pipe to convert it to a male outer thread to screw the stove line onto. Use gas rated (yellow) Teflon tape.
Question

Is gas piping threaded left to right or right to left?

Gas piping typically is threaded clockwise to tighten and counter-clockwise to loosen.
Question

If I am replacing an electric water heater with a gas heater, can I T off a half-inch pipe that is connected to my stove and run both the water heater and stove on the half-inch pipe?

Probably not. Gas appliances have supply requirements, a sufficient volume of gas flow per minute to allow the appliance to do its job properly. A 1/2" line currently running to your stove should supply sufficient gas for the stove, and was sized accordingly. Adding a T fitting and running a parallel supply to your gas water heater will likely starve both appliances for gas when both are operating. There's actually a formula for sizing gas pipes, and while it's not that difficult, it is important. You have to determine the BTU rating of each appliance, which helps determine the right volume of gas delivery to the furthest appliance; then you work your way back. Hire a pro.

Show more answers

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

Video

You can also test your gas line by disconnecting the main line from the meter. Install a pressure gauge with a way to fill the line with air. Then fill the line with about 25 pounds of air. Check your line for leaks with soap and water. If no leaks recheck line pressure and let it set overnight. If there is no pressure loss there is no leaks in the line. It would be best to have an inspector check your line pressure and come back and sign off on it.
All states require you have to have a shut off valve to the appliance. Also you have to have a tee with a 2" nipple or greater with a pipe cap to act as a dirt trap/leg. One end of the tee hooks to the gas line coming through the floor, then your tee faces down with your nipple, then your valve, and next your flex hose to the appliance.

Thanks for submitting a tip for review!

Ensure proper line sizing was used to handle the BTU load you will be drawing with the new appliance.
This is not a job for beginners. If you've never worked with gas lines before, get an experienced friend to coach you through your first attempt.
A pressure test should be done prior to firing up any appliance to avoid explosions.^[6]

Things You'll Need

Gas pipe and fittings
Pipe wrenches
Pipe glue or tape
Dish soap

References

About This Article

Thanks to all authors for creating a page that has been read 566,606 times.

Did this article help you?

Get all the best how-tos!

You're all set!