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Photograph of  this gas flame which gives a clue that there may be an operating problem and an unsafe gas furnace in this building Find & Inspect LP & Natural Gas Appliance Shutoff Valves
Manual & automatic gas shutoffs

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LP, Propane or Natural Gas Shutoff Controls & Valves:

This article describes the common locations of and inspection of LP or Natural Gas shutoff valves at heating appliances, stoves, and clothes dryers. A gas shutoff is a manual valve that can be closed to stop the supply of natural gas or LP gas to a heating appliance or to a building.

We distinguish between a gas shutoff valve and a gas regulator, which may also be called a gas valve but which has the job of controlling gas flow into a heating appliance automatically in response to a call for heat.

Our page top photo shows a gas shutoff located at an outdoor gas meter - the valve is on the leftmost of the two vertical gas pipes at the top of (this improperly installed) gas meter.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

How & Where Locate & Inspect Natural Gas or LP Gas Fuel Shutoff Valves

Photograph of  this gas flame which gives a clue that there may be an operating problem and an unsafe gas furnace in this buildingMain Building gas shutoff valve located at the gas meter

A main building gas shutoff valve are normally located at the main gas meter.

An additional shutoff valve may be located in the street or sidewalk outside of the building - a device that cannot be readily seen nor used by a building owner.

[Click to enlarge any image]

We can see that the gas valve is in the "open" position because the movable lever is in the "down" position and parallel to the gas pipe.

Most gas companies advise their customers not to touch this valve.

They worry that you'll damage the valve and cause a more serious gas leak than ever.

Call your local gas company for assistance with the valve or the meter. Usually, because serious safety concerns apply, the gas company will respond immediately.

Watch out: General safety warning: improper installation and even improper inspection and testing methods involving natural or "LP" gas can involve dangerous conditions and risk fire or explosion.

If you smell gas you should leave the building immediately and should do so without doing anything that could create a spark such as operating a light switch or telephone.

LP gas tank shutoff (C) Daniel FriedmanFrom a safe location, call your gas company's emergency line and/or your fire department. 

The text provided here is a working draft and may be incomplete or inaccurate. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.

Also see How to Report Defects in Oil Piping. NOTICE: while example report language is provided here, reproduction of this or any of our web pages or their contents at other websites or in printed documents for sale is prohibited.

Our photo shows the shutoff valve on an outdoor LP gas tank.

The direction to turn the valve to "close" it is marked by an arrow on the valve.

You should find an document the location of the main shutoff gas valve (usually located at the gas meter or if the meter is outdoors, a main valve may be installed inside the building close to where the gas pipe enters the structure.

The LP gas tank shutoff control (photo at left) is the gray knob at the right side of the picture.

Gas shutoff valves at individual gas-fired appliances

Next you should find and document the location of individual gas shutoff valves at each appliance in the building that uses gas.

Building codes require that a gas shutoff be located at each appliance and outside of the jacket or cover of the appliance.

Gas shutoff valve on a water heater (C) Daniel Friedman Gas shutoff valve on a gas furnace (C) Daniel Friedman

Our photos show a natural gas shutoff valve installed at a gas-fired water heater (above left) and a gas shutoff valve installed at a gas-fired warm air furnace (above right).

Outside gas shutoff for appliance (C) Daniel Friedman

Typical gas fired appliances that would each have its own gas shutoff valve include gas fired boilers or furnaces, clothes dryers, water heaters, and gas fired cook stoves or range tops.

In some cases such as where a damaged or corroded flexible gas connector line joins the appliance to the building gas piping, moving the appliance could start a dangerous gas leak.

In these cases, such as a range top, gas stove or clothes dryer which may be pushed against a building wall, we like to see an additional gas shutoff valve for such appliances located in a more accessible location.

This permits the user or repair technician to turn off the gas supply without moving the appliance.

Our photo (left) shows a shutoff valve in an LP gas line that supplies a gas fired range top in a building where there was no other readily accessible location to provide a shutoff valve close to the appliance.

The range top was installed over an oven. An additional shutoff valve was installed inside the building but could not be readily accessed without lifting the range top or removing the oven below.

Automatic Gas Shutoff Valves on Water Heaters, Temperature-Operated

Watts 210-5 automatic gas shutoff valve on a gas fired water heater (c) InspectApedia.com DelCerro

Above is a Watts 210-5 automatic gas shutoff valve installed at the temperature-pressure relief valve on a gas fired residential water heater.

The gas piping has not been connected. Gas supply piping is passed to the Watts 201-5 and from it outlet onwards to the water heater's own gas controls and burner.

The Watts 201-5 valve shown will shut off the gas supply if water temperature exceeds 210°F.

Details about this gas fired water heater automatic gas shutoff valve are at AUTOMATIC GAS WATER HEATER SHUTOFF - temperature operated gas supply shutoff for water heaters, Watts 210-5 series.

Visual Signs of LP Gas Leakage at an Appliance Gas Valve

Leaky LP gas valve (C) Daniel Friedman

Even if the natural gas or LP Gas is shut off or no longer supplying an appliance, stains at the gas piping such as we show below this little LP gas shutoff at a water heater (in a city in Mexico) may indicate a history of leaks at the gas pipe connections.

In this case we found that a damaged, grooved mating face on a flare fitting had caused many years of slow gas leakage at this valve. T

he black stains at the flare fitting and copper tubing at the left side of the valve (photo at left) were pointed-to by the gas delivery driver as evidence of a history of gas leaks.

The repair required replacement of a flare fitting and re-making the joint.

Gas shutoff valves located inside of heating appliance covers and jackets

Photograph of  this gas flame which gives a clue that there may be an operating problem and an unsafe gas furnace in this building

Safety Recommendation: a gas shutoff valve should be installed in the gas line close to (but outside the cabinet of) each gas-fired appliance/device. [There are a few exceptions that permit the valve to be inside the appliance - ed.]

If your building has gas fired appliances that lack an accessible gas shutoff valve you should ask a licensed professional plumber or heating technician to install one.

Safety Recommendation: If you see that the local manual gas line shutoff valve at a gas-fired appliance has been installed only inside the jacket or cover, this is an unsafe condition: the valve could be difficult to reach in an emergency.

Check with your local building code inspectors. Relocation of such valves is usually a minor expense and can be handled by most licensed plumbers or heating service technicians.

Abandoned gas shutoff valves may be very dangerous

Abandoned gas valve (C) Daniel Friedman

Gas valves might be found be left in place when an appliance has been removed.

Gas light still working (C) Daniel FriedmanWatch out: If the gas valve does not include a lock to prevent it from being opened, the gas pipe should be capped so that the valve cannot be opened to let explosive gas into the building.

Our photo (left) shows a "live" natural gas line in an old house in Newburgh, New York.

Someone who doesn't know better might open this valve, causing a serious or potentially fatal explosion in the building.

Gas surprises: Gas light and gas fireplace lines and valves may be "live" in older homes which used natural gas to supply energy to gas fireplaces or even to gas lights.

Never assume that an old gaslight fixture (photo at left) is safe and that the piping does not contain gas.

Often these fixtures were converted to electricity, having wires run conveniently through existing gas piping.

But an old gas fixture that has not been electrified may still release dangerously explosive gas into a building.

Types of Gas Shutoff Valves

Nibco gas ball valve used as gas shutoff for LP or Natural Gas - cited in detail at InspectApedica.comFor safety be sure that the shutoff valve you select for installation on gas piping is rated and approved for that application.

Do not use a water shutoff valve on gas piping.

Furthermore at least some gas shutoff valves include in the product description a warning not to use the valve on water piping.

Shown above: a NIBCO gas rated ball valve with a red handle.

This is a low-pressure gas line shutoff described by NIBCO as

5 psi for indoor shutoff per CGA 91-002 and ASME B16.44, 1/2 psi for indoor appliance connections per ANSI Z21.15 and CSA 9.1, Not for water service. - Source cited at the end of this section.

 

Question: ok to use an "LP"-marked shutoff valve on natural gas piping?

2018/11/22 Sparky said:

Can a shut off valve that is marked “LP” on the handle be used as a natural gas shut off valve? The color of the handle is red and I have seen yellow colored handles before and wanted to know the difference.

Reply: Yes but check the valve markings or labeling for use with gas piping - do NOT rely on the color of the valve handle

Sparky

Gas valves intended for use as shutoff controls for either LP or Natural Gas are marked with specific sampings that identify them as gas shutoffs. In North America look for an AGA stamp on the gas shutoff valve body or in Canada, a CSA stamping along with additional stamps and marks we will discuss here.

Do not rely on the color of the valve handle as an indicator of its intended use.

Eastman Gas ball valve for LP or NG lines, using a flare fitting cited in detail at InspectApedica.com

While a gas valve handle color is often yellow or red you will also find gas-rated shutoffs with valve handles in other colors such as green or blue.

Plumbers don't rely on the gas valve handle color. More-often the valve handle color is simply part of the manufacturer's brand identificaiton.

Not to mention confusion that could arise from the fact that that valve handles can be replaced or swapped on and off on the same valve.

Shown here are two gas ball-type valves produced by Eastman. One valve has a red handle (above) and the other Eastman valve has a yellow handle (below).

Both of these in-line flare type (internal ball type) gas valves are permitted for use on on either LP (propane) and NG (natural gas) piping.

Both of these valves are rated for use on either LP gas piping or natural gas piping.

The red-handled gas shutoff above is described as:

The yellow handled gas shutoff valve shown below is described by the company as:

Eastman Gas ball valve for LP or NG lines, using a flare fitting cited in detail at InspectApedica.com

These valves do differ: the red-handled gas valve is a right-angle or 90 degree valve connecting NPT to flare piping

while the yellow handled gas valve is a straight or in-line gas valve connecting NPT to a flare fitting (copper tubing).

A final comment on LP / Natural Gas shutoff valve interchangeability:

Watch out: do NOT use a control valve rated just for water on gas piping, even if it's a ball-type valve.

Shutoff valves rated for use on gas piping will generally be stamped "G" (for gas) or "WOG" for (ok to use on Water, Oil or liquid Gas piping).

A valve intended for use on gas piping will have an AGA stamp on it (American Gas Association) for valves sold in the U.S.

If you see a valve that is stamped "W" (water only) its internal seal is not as reliable as a valve rated for use on gas piping: such valves should not be used on gas pipes.

Look at the valve's body or rating for an AGA stamp, or look at the information provided by the manufacturer on a data tag attached to the valve.

Also in some communities the gas piping materials that are permitted for LP may not be permitted for natural gas & vice versa.

For example you may be required to use black iron piping rather than flexible copper tubing in some piping installations (such as running gas lines through concealed spaces).

Gas Control Valve for Appliances

FireMagic gas appliance valve without orifice - at InspectApedia.comWatch out: however SOME gas control valves used at, on, or within appliances like gas grills and ranges may be sold with a metering orifice for use with a specific gas (LP or natural gas) and for a specific appliances. THOSE gas valves are NOT interchangeable.

For example a gas range top or cooktop gas control valve may be specifically set up for LP or NG and can't be swapped without conversion of an internal orifice.

Here I show as illustration a gas control valve sold by Fire Magic Grill Parts. This brass gas control valve is rated for use on both LP (propane) AND Natural Gas.

Watch out: this valve is not intended as a general-purpose gas line shutoff valve. It is sold as a gas control for use on certain models of FireMagic's gas grills.

In GENERAL (but not in every case), a gas control valve that is rated for LP ought also to be fine for natural gas - there is not such difference in delivery pressure as to require a different design. Here I am referring to a gas piping or gas supply line shutoff valve that might be installed close to the gas appliance.

Below is what the vendor says about this valve:

FireMagic main burner brass control valve. Features an adjustment screw, located at the bottom inside of the valve stem, that enables the valve to be used with either propane or natural gas. This valve does not come with an orifice.

Fits FireMagic Regal 1 and 2, Custom 1 and 2, Deluxe, Elite and Monarch models. IMPORTANT: Orifice "Not" Included. Replaces FireMagic OEM Part 3004. - retrieved 2018/11/25 cited in detail below.

Changing From LP to Natural Gas or Natural Gas to LP?

Watch out: you cannot simply switch fuels from LP to natural gas and expect the same, un-modified appliance to work correctly. Doing so would be unsafe, risking a gas fire or explosion as well as improper device operation.

In the ARTICLE INDEX found near the end of this article you'll find articles on

In those articles you'll see that both the gas regulators and orifices and other controls must be changed or modified.

Gas Line & Appliance Valve Suppliers

Gas Line Fire Safety Valves

Gas line safety valve from Preferred Utilities, Danbury CTFire safety valves for gas fuel lines that can shut off fuel supply in the event of a fire are also available, such as the Model 110-G Fire Safety Gas Shut-off Valve used in fuel gas piping systems and provided by Preferred Utilities (http://www.preferredutilities.com) in Danbury CT in the U.S. As Preferred explains:

The valve is held open by a stretched wire containing a fusible link.

When the temperature rises above 165° F, the link will melt and the tension of the internal spring closes the valve.

The gas line safety valve installation instructions from Preferred include:

Locate the valve in a horizontal pipe run where the supply enters the boiler room, and/or each device or where dictated by code. Install the hold-open wire with the link(s) located in the area(s) to be temperature monitored.

Enough tension should be placed on the stretched wire to keep the valve in an open position. 

Gas Line Safety Valve Sources

Similar fuel supply fire safety valves for oil fired heating equipment are described at OIL LINE SAFETY VALVES, OSVs.

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Continue reading at GAS REGULATORS for APPLIANCES or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see AUTOMATIC GAS WATER HEATER SHUTOFF

Or see GAS APPLIANCE CONVERT LP-NATURAL GAS

Or see GAS PRESSURES LP vs NATURAL GAS

Suggested citation for this web page

GAS SHUTOFF VALVES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to GAS APPLIANCES, PIPING, CONTROLS

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