This project shows to install new natural gas shutoff valve, black iron pipe fittings and quick connect coupling to hookup a BBQ gas grill. Please hire a licensed plumber if you need to run a new natural gas line to the deck or patio because natural gas leaks can cause fires and explosions. This project is continued from How to Replace Deck Ledger Flashing – Part 2.
How to Install a Natural Gas Shutoff Valve for a Grill
A 1/2 inch natural gas line to the wood deck was installed by the home builder. At the beginning of the sagging deck repair project, the quick disconnect coupling was removed and the black iron pipe capped with a 3/8 inch plug. The pipe plug prevented accidental gas leakage if the shutoff valve were bumped during construction. The natural gas valve needs to be removed to install the new deck board.
The parts to replace the natural gas shutoff valve are:
- American Valve 1/2 inch In-Line Gas Ball Valve Model #M88C.
-
1/2in x 3/8in black iron reducing coupling.
The reducing coupling is required because natural gas quick disconnect couplings and hoses are 3/8 in. - 1/2in x 2-1/2in black iron nipple fitting.
-
RectorSeal No. 5 pipe thread sealant.
RectorSeal No. 5 is rated for natural gas applications.
Take care to use only black iron pipe fittings and valves rated for natural gas service.

Shut Off the Natural Gas
My house does not have a main or “house-side” shutoff valve inside the home. If there were a house-side valve it would be located close to where the gas pipe enters the house in the basement. My only option for shutting off the gas is the “street-side” valve on the supply side of the natural gas meter.
Contact your natural gas company. Gas companies prefer that you do not turn Off the gas except in an emergency. More importantly turning the gas back On requires special care to prevent gas leaks, fires and explosions. The gas company can turn off the gas for you, and when you’re ready, turn it On, relight and check your appliances.
The next steps are for information only. Contact your gas company or hire a licensed plumber.
Cautionary Gas Shutoff Steps:
- Turn off all natural gas appliances in the home, including fireplaces, cook tops, clothes dryer, water heater, furnaces, etc. Each appliance should have an individual gas supply shutoff valve. See the furnace and fireplace shutoff valves for examples.
- Determine which appliances have electronic ignition (e.g. furnaces, cook tops) and which ones require manually relighting a pilot light.
My water heater is the only non-electric ignition gas appliance that I have to manually relight and the fireplace gas logs valve was Off. Read your the gas appliance user manuals for start-up procedures.
The street-side natural gas valve at the meter is in the On position.

Use a wrench to shut off the gas by turning the valve 90 degrees:

Remove the Old Natural Gas Shutoff Valve
Remember – no smoking! The natural gas line pressure inside the home is typically 1/4 PSI to not more than 2 PSI – it’s not much but some natural gas will vent as the valve is removed and you’ll notice the rotten egg odor.
Having shutoff the natural gas supply to the home, I removed the old natural gas shutoff valve for the BBQ grill. A pipe wrench is required to hold the supply pipe and prevent it from turning, otherwise the elbow joint under the deck may leak! Place an adjustable wrench on the shutoff valve body and unscrew it:

Set the Deck Board in Place
I had previously measured and drilled a 1-1/4 inch diameter hole in the 5/4 x 6 inch deck board for the gas supply pipe. Now I set the board over the gas pipe having removed the old gas shutoff valve.
Install the New Natural Gas Shutoff Valve
Stir the RectorSeal and swab it on the male pipe threads only for pipe diameters up to 1-1/4 inch. The natural gas supply pipe is 1/2 inch diameter:

Screw on the shutoff valve until finger-tight. Then hold the gas pipe with the pipe wrench to prevent it from turning and tighten the valve with the adjustable wrench. Next, coat one end only of the 1/2in x 2-1/2in black iron nipple fitting with sealant:

I chose the 1/2 inch x 2-1/2 inch long pipe nipple to have room to get the pipe wrench on it. Spin the nipple into the shutoff valve by hand, hold valve body with the adjustable wrench and tighten the nipple with the pipe wrench. (I had to put down the adjustable wrench to take the photo.)

Swab sealant on the pipe nipple top threads and install the 1/2in x 3/8in black iron reducing coupling. Hold the valve body still with the adjustable wrench, place the red pipe wrench on the coupling and tighten:

There’s a lot of work remaining on the deck rebuild project, so I installed a 3/8 inch black iron pipe plug to prevent bumping the gas valve and causing a leak. The plug will also keep out dirt and rain water. Seal the plug threads with RectorSeal No. 5, hold the reducing coupling with the pipe wrench and tighten the plug with the adjustable wrench:

Turn on House Natural Gas Supply
I turned the gas supply valve at the meter back On, turned On the various appliance shutoff valves, relighted the water heater pilot light and checked the gas cook top and furnace operation. No rotten egg odors and everything was back in operation.
This project is continued in How to Install a Natural Gas Shutoff Valve for a Grill – Part 2.
Take care,
Bob Jackson