gas oven safety valve leaking factory

Gas ovens contain a number of valves depending on their age and design: pilot safety valves, oven safety valves and thermostatically controlled valves. Any of these valves contain gaskets that may leak with age as well as develop leaks where they connect to the oven’s system of gas pipes or tubing. Older ovens that use the oven’s control knob to control gas flow are prone to develop leaks because of the constant use this control receives.

I have a six month old range. Gas supply line installed professionally and no leaks at gas valve or connection to stove. I can use top burners fine. When I use the oven there is a noticeable gas smell after several minutes. Oven will preheat fine, but as it continues the gas smell begins to build as the unit cycles to keep temp or increase temp. Anyone walking in the house would say there’s a gas leak. I got a combustion meter, and it shows no leaks anywhere in the supply connections or at the connection to the stove when the oven is on. The meter goes off the charts when testing the top, middle area at the back of the stove where heat would come out. You can smell the gas with your nose after a while.

I have a GE tech from A&E Factory coming out this week to look at the stove. Any thoughts ahead of time on what this could be? A valve not closing well enough? Thanks.

The valve pictured needs to be replaced immediately please. That type of valve is not only out of code but few know that it needs regular grease maintenance every few years, now ask yourself has this been greased in the last 10 years or 20? I think not. Spend the time and put a ball valve so in an emergency you will not have to find a tool to shut it off if the appliance developes a leak. My mother in law had a 5 year old gas stovetop go poof on her last year, luckily it just scared the pants off her but the inner explosion was forceful enough to unseal the stovetops gasket connecting the factory upper half to lower half. Leak was caused by maids over cleaning and getting cleaner over the years down into casing by spraying stovetop with cleaner. The cleaner along with any spills caused the dissimilar metals of the gas tube and appliance casing touching and caused a hole is my best theory after dismantling and inspection of the unit. Be safe replace it and make sure to add a auto off check valve also. But hey its only the life of you and your family we are talking about over 10 dollars in parts.

Valves that leak internally can lead to major losses of valuable product, or unintended transfer of process constituents, in some cases seriously elevating process risks. Surveys are carried out to check valves that are expected to be closed during normal operating conditions. The primary purpose of such surveys is to determine whether the valves are in a fully closed and sealed position, and thus not passing product to the flare systems or other lines due to a seal failure.

Acoustic survey techniques combined with an empirical correlative database may be used to estimate the mass flow passing through a partially closed valve based on the monitored acoustic signal.

Acoustic and infrared techniques may be used to determine whether a valve is passing or not. The net outcome of this survey approach is a pass/no-pass survey result.

The U.S. Environmental Protection Agency (U.S. EPA) under the Greenhouse Gas Mandatory Reporting Rule for Petroleum and Natural Gas Systems has required that subject facilities perform leak detection(s) of equipment leaks and through-valve leakage using any one of the following methods (

Use of an acoustic detection and quantification device: A study on refineries showed that a small percentage of valves are passing, and that a smaller part of them is responsible for the majority of leaks. In order to identify the large contributors, it is necessary to quantify those leaks. A portable tool available on the market allows for quantification of the internal leaks in valves for single phase fluids (gas, liquid and recently, steam), based on acoustic detection. The measurement is quick (two minutes per valve) and non-intrusive. The noise of surrounding rotating machines generally does not affect the measurement but, in some specific conditions, the nearby ΔP of fluids can disturb the measurement. This device also has the added benefit of allowing an analysis of the integrity of a isolation valve (since some are exposed to sand erosion) for valves connected to the flare, in order to improve performance with respect to safety, production and environment (

Detection of a passing valve using the Joule-Thomson effect principle through the valve: This principle consists of identifying a lower temperature downstream of the valve compared to the temperature upstream of the valve. This method can be applied with a thermal gun. The advantage of this method is that it requires standard equipment (‘thermo gun’). However, this method does not accurately detect passing valves in all cases (Presence of ice or condensation in case of high ΔP through the valve. In the case of high temperature upstream of the valve and/or low ΔP, the temperature downstream of the valve can be higher or equal to ambient even though it is passing.

When the section upstream of the valve is hot, it may indicate that gas passes through the valve. But for large diameter pipes, natural convection within the pipe can make the pipe upstream of the valve be hotter than downstream, even though there is no gas passing through the valve.

Listening for audible noises caused by the energy dissipated in the passing valve. This method can work in some cases, but can be disturbed by nearby machine noise.

Use of an ultrasound stethoscope: this tool is different from the device mentioned above for the acoustic detection of a passing valve. It sends an ultrasound wave into the valve which bounces back and is converted into sound for the surveyor to hear. The operating frequency has to be selected carefully so that nearby noises do not disturb the measurement. Efficacy of this method is still to be confirmed.

On-off ball valves [emergency shut-down valve (ESDV), shut-down valve (SDV), blow-down valve (BDV)] can be verified for full closure on the outside (the stem position will be clearly visible), whilst limit switches attached to the valves would detect a false closure (>3 degrees open or closed). ESDV valves should be equipped with ‘partial stroking test’ capabilities to test the integrity of the valve control panel and the physical condition of the valve. However, this partial stroke feature is not installed on BDVs. For BDVs (to the flare), operations will frequently close the manual valves upstream and downstream of the BDV and then open and close the valve via the ESD system to ensure that the valve is properly functioning. Ball-and-seat alignment verification could also be carried out, but this requires dismantling the valve.

Pressure safety valves (PSVs) are a well-known source of leaking/emissions. However, leak detection can be challenging. Most PSV leakage comes from improper re-setting of the disc on the nozzle, causing gas passage. Current practice is to dismantle and overhaul a PSV whenever it has been opened (even once) as a safety precaution.

Control valves should be properly specified according to their purpose, with cost as a secondary consideration only. Full valve stroke testing is not always possible during operations: control valves are typically the most important pressure control valves in the plant, and stroking can seriously disrupt production (and cause flaring) if no bypass or other backup is available.

In gas exporting fields, repairing or routing the passing valves to flare (valves with internal leaks, connected to the flare system) can have a high return on investment with cost recovery within weeks or months.

The following technologies provide similar benefits and may be considered as alternatives to acoustic detection for identifying passing valves (see section on "Passing valve identification without dismantling or isolation’, above).

In this industry case study, acoustic leak detection equipment was purchased for around €50,000 to perform a survey of valves in a downstream facility. The objective was to test about 150 valves, but the crew was not able to test them all due to (i) lack of time and (ii) inaccessibility of some valves (located in areas which required the installation of scaffolding). The following is a summary of the work performed and the findings:

16 valves were identified with high leakages: Of the 16 valves, four valves had significant leakage flow (flow rate passing through the valve on the order of 6–15 kSm3 / day gas).

U.S. Federal Regulation: "Mandatory Greenhouse Gas Reporting for Petroleum and Natural Gas Systems’ (Regulation 40, Part 98, Subpart W). Electronic Code of Federal Regulations (e-CFR data), 2013.

Carbon monoxide poisoning symptoms can be similar to those of a gas leak. If you"re exposed to carbon monoxide, it can be fatal. If you think you or your loved one are experiencing carbon monoxide poisoning, seek emergency medical treatment immediately.

For mild leaks, turn pilot lights off, open your windows, and contact your gas company. They"ll tell you what to do and whether the gas meter needs to be turned off.

If you"re noticing symptoms or a strong odor, leave your home immediately. Remember that gas is volatile and can cause an explosion. Call the emergency number for your utility company immediately in a safe location.

In case of an emergency and you need to shut off your gas, you"ll want to locate your natural gas meter. Try to locate it before an emergency so you"ll be ready. You can have an underground, cabinet, under-the-house, or multiple meters. Only turn off natural gas if you hear gas escaping or can smell it.

Only turn it off if it"s safe to do. Next, you"ll see a pipe from the ground to the meter. Locate the shut-off valve. Use a 12-inch or bigger adjustable wrench, and turn the valve 1/4 in either direction. Turn it until it"s crosswise to your pipe.

Don"t turn the gas back on yourself, wait for a certified professional. Natural gas shut-off valves are a safety feature to incorporate. If a leak happens at an appliance, you can turn off the natural gas at that appliance. Always use caution when you touch risers, meters, and any other attached components.

Never try to repair a gas leak on your own, always call and wait for help. Don"t keep your doors closed or make calls from your home. Don"t think someone else will report the leak. During a leak, don"t use household appliances or turn the lights on and off.

Always keep your children away from natural gas appliances. It"s also a good idea to teach them about natural gas safety. Keep areas around appliances unblocked and clean for proper airflow. Natural gas can build up if it can"t circulate through vents. Ensure you have carbon monoxide detectors on each floor and in the bedrooms.

Have at least one fire extinguisher in your home as well as heat and smoke detectors in case a fire was to occur. Keep flammables and chemicals away from your gas appliances. Have gas lines, chimneys, vents, furnaces, and gas appliances inspected every year by qualified professionals.

Keep a fire extinguisher in your kitchen. Don"t store combustible materials such as gasoline, solvents, or paints in the same area as your oven, furnace, water heater, range, or other gas appliances.

When a pilot light is out, shut off the gas at the appliance gas shutoff valve. Before relighting the appliance pilot light, wait 5 minutes for the gas to disperse. Have a crescent wrench or adjustable pipe near your main shutoff valve in case of an emergency.

Never keep flammables near your oven, range, heater, furnace, or gas appliance. Flammable materials can include newspapers, laundry, brooms, and mops. Don"t use a candle, match, or flashlight to look for a gas leak. Don"t turn electric switches off or on if you think there"s a leak.

When you think you"ve found a gas leak in your home, don"t panic. Ensure you follow all of these safety procedures and contact a qualified professional immediately.

First developed for use on early steam boilers as operating without them would cause an explosion unless carefully operated. Modern burner ovens now feature a gas safety valve to prevent an explosion when unlit. Unless ignited by an electric glow bar, pilot flame or electric spark with a gas supply, the valve will remain closed.

Safety should be you’re top priority when you’re working with gas. If you’re not careful, its extremely easy to cause a lot of damage. To prevent this modern day gas safety valves have been fitted around the world, to ensure an efficiently working system.

When your gas safety valves are on their last legs, making a repair or finding a replacement is the best thing to do. Keeping a spare in your kit is highly recommended.

The glow bar igniter and safety valve are wired in series within a glow bar system. This means that electricity can only pass through the valve after it has first passed through the glow bar. Electrical resistance from the glow bar blocks current to the gas valve, making sure that the valve closes. This decreases as the temperature increases. When the bar reaches a particular heat, enough to ignite the gas, it allows sufficient electricity through to open the gas valve.

The gas ignition source on Pilot light ignition system uses a low flame, fed by a line from the thermostat. The pilot flame will either burn constantly or be ignited electronically when the oven is switched on. More gas is fed to the pilot flame when the oven thermostat wants heat. Either excess pressure or an electric current will open the gas valve.

With some ovens the burner is directly ignited with an electric spark. An electric spark is sent to ignite the burner when the gas valve opens, this is due to the thermostat wanting heat. A sensor on the burner detects the flame and confirms ignition. The oven burner will lock out if there is no ignition after two attempts.

Pressure relief valves are usually installed in multi appliance, oil pumped ringmain systems. They are used to maintain a constant pressure on the positive side of the pump whether all appliances are in use or not.

Safety relief discharge pressurised gases and vapours to protect against overpressure. This is done by discharging pressurised gases and vapours from pipelines, this includes pressure vessels and plant components. Safety relief valves are the last line of defence and prevent explosion which could be fatal.

These spring-loaded and direct-acting. When the opening pressure is reached, valve gives way and opens, releasing the pressure. The pressures then equalised and the automatically closes.

Relief valves can either discharge into atmosphere, or via a connected blow-off line. The opening pressure of the boiler relief valve valve is preset usually at the factory according to the customer’s requirements.

About half of homes in the U.S. use natural gas to power furnaces, stoves, ovens, water heaters, and other appliances, and 8 percent use petroleum, which includes heating oil, kerosene, and liquefied petroleum gas (LPG).

But natural gas is highly combustible. This means it can produce a lot of heat when you burn small amounts, but it also means that a natural gas leak can pose a serious risk of fire and explosion since it spreads quickly and goes up in flames easily. If you have a gas leak in the house, any electrical spark or fire source can ignite the gas—with results that can be devastating.

It"s important for everyone in your family to be educated about gas leaks, as a leak in or around the home can be quite dangerous. Even if it doesn"t ignite, a natural gas leak can, at certain levels, kill you through suffocation. In much the same manner that carbon monoxide can kill by preventing the body from absorbing oxygen, natural gas or LPG in the air at high concentrations can have the same effect.

To help ensure that you live safely using natural gas, be aware of the signs of a gas leak. A gas leak indoors is the most dangerous, since the levels of gas in the air can quickly build up to levels that are toxic and highly explosive, so it is important to know the signs:

Unpleasant smell: Neither natural gas nor liquid propane has any color or odor, but utility companies include an additive that gives the gas a highly distinctive odor that almost anyone can recognize. Known as mercaptan or methanethiol, this substance is harmless but pungent-smelling; it is often described as having an odor like rotten eggs or rotting cabbage. If you can smell this odor in your home, it is likely that you have a gas leak.

Hissing sound: A hissing sound coming from the area around a gas appliance is often a sign of a gas leak. This is a highly dangerous situation since it means that large quantities of gas are escaping. If you can hear a gas leak, you almost certainly will also smell it. Don"t try to fix the connection yourself; leave the house and call the utility company to investigate.

Dead house plants: Plants are extremely sensitive to any buildup of gas in the air, and they may begin to die before you can detect any gas odor in the air. Failing house plants may indicate you have a slow gas leak that is otherwise undetectable.

Visible air movement: A gas leak from an underground pipe can cause dirt to be thrown into the air or plants to be blown, as if by a breeze. Unusual air movement from the ground near the home is a possible sign of a gas leak.

Bubbles: A leak in a gas pipe can sometimes cause bubbling in moist ground areas around the home. A water puddle that bubbles may be hiding a leaking underground gas pipe.

Dying plants: Plant life near a gas leak will become sickly and eventually die. While plants can certainly wilt and die due to a variety of reasons, plants that die without an obvious cause can indicate a gas leak. A natural gas leak blocks a flower"s source of oxygen and fruits and vegetables will change color when they come in contact with natural gas. If you see dead or discolored plants surrounded by healthy green plants, it is worth investigating.

Dry spot inside an area of moist ground: A gas leak can dry out moist ground, so if you see an unusual spot of dry earth within a moist area, it may mean that leaking gas from an underground pipe is drying out the soil.

Ground on fire: A clearly defined blue or yellow flame coming from the ground, or a flame appearing to hover above the ground, is a clear sign of a gas leak in an underground pipe. Move far away from the area and call the authorities immediately.

If you suspect a gas leak in or around your home, stay calm, stop what you"re doing (don"t turn any electrical switches on or off or unplug anything), and go outside immediately. Inhaling high concentrations of natural gas can lead to asphyxia—a potentially fatal condition in which your body is deprived of oxygen, and you may not recognize it until it is too late. Once you"re at a safe distance from the house, call your gas company to come and inspect for leaks. Utility technicians have special tools that can detect even minute amounts of gas in the air.

Just because you don"t detect the familiar rotten-egg smell doesn"t mean you may not be in danger. There still may be small quantities of gas that are affecting you and your family, so it is better to be safe than sorry.

WITT is a manufacturer of Pressure relief valvesor Safety relief valves for technical gases. They are designed to protect against overpressure by discharging pressurized gases and vapors from pipelines, pressure vessels and plant components. Safety relief valves (SRV) are often the last line of defense against explosion – and such an explosion could be fatal. Other common names for safety relief valves are pressure relief valve (PRV), safety valve, pressure safety valve, overpressure valve, relief valve or blow-off valve.

WITT safety valves are very precise. They are individually preset to open at a predetermined pressure within the range 0.07 to 652 Psi. Their small size and orientation-independent installation allow a wide range of connection options. WITT relief valves also stand out due to their high blow-off flow rates of up to 970m³/h. They can be used within a temperature range of -76° F to +518°F and even with very low pressures.

For maximum safety, WITT undertakes 100 % testing of each safety relief valve before it is delivered. In addition, WITT offers individual testing of eachsafety valveby the TÜV, with their certificate as proof of the correct set pressure.

WITTsafety relief valvesare direct-acting, spring-loaded valves. When the preset opening pressure is reached, a spring-loaded element in the valve gives way and opens, and the pressure is relieved. Once the pressures are equalized, the valve closes automatically and can be reactivated any time the pressure rises again. Depending on the application and the nature of the gas, the safety relief valvescan either discharge to atmosphere, or via a connected blow-off line. The opening pressure of the safety valves is preset by WITT at the factory according to the customer’s requirements.

Safety relief valvesare used in numerous industries and industrial applications where, for example, gases pass through pipelines or where special process vessels have to be filled with gas at a certain pressure.

For most industrial applications using technical gases, brass is usually the standard material of construction of thesafety relief valvebody/housing. For the use of pressure relief valves with aggressive and corrosive gases, the housings are made of high-quality stainless steel (1.4541/AISI 321, 1.4404/AISI 316L, 1.4305/AISI 303 or 1.4571/AISI 316Ti). The use of aluminium as a housing material is also possible.

Depending on the type of gas used and individual customer requirements, various sealing materials and elastomers are available to ensure the safety of your systems under even the most difficult conditions.

WITT pressure relief valves are available with different connections. In addition to the standard versions with the usual internal or external threads, special versions with KF or CF flanges, VCR or UNF threads can also be ordered. Special adapters for connecting the safety relief valve to a blow-off line are also available.

When the burners on your Pitco fryer flicker or the pilot light refuses to stay lit, or the pilot light is on but the burners won’t ignite, there’s a fair chance the problem is with the unit’s combination gas safety valve.

Pitco uses two basic styles of gas safety valves. One is found on units with a permanent pilot light. It uses a thermocouple to regulate the gas valve. The other is used on units with electronic ignition switches. This version uses a millivolt system and a thermopile to generate enough current to open and close the main gas valve. If the thermocouple or the thermopile (depending on the fryer) detects a flame, it won’t signal the gas valve to open. To determine which type of valve your unit has, check the model of the fryer and the user’s manual.

Before replacing the combination gas safety valve, eliminate the other likely suspects – clogged gas orifices, the hi-limit, the thermopile, and the thermostat. Often, problems that could be caused by faulty combination safety valves can be resolved by clearing the gas orifices or by replacing one of these components.

Checking the combination safety gas valve last is a matter of convenience. The process of checking or replacing the valve is relatively easy, but it’s not necessarily easy to reach.

That said, use a direct current multimeter set to the 0 to 1000 millivolt range to test the voltage at the points where the thermopile or thermocouple connects to the combination gas valve. To do this, locate the thermopile wires connecting the pilot to the gas valve. Connect the positive (+) test probe to the top “PP” terminal with the red wire. Then connect the negative (-) test probe to the lower “PP” terminal with the white wire. (Check the diagram in the manual for the 35C+ and 45C+ units.)

The voltage should be 550 millivolts, plus or minus 50 millivolts. (At or below 200 millivoltags, the thermopile lacks the energy to regulate the burner valve.)  If the voltage is not around 550 millivolts, use a Phillips screwdriver to loosen or tighten the pilot adjuster screw, located beneath the pilot on/off switch. Wait three to five minutes between adjustments to allow readings to stabilize.

If this doesn’t fix the problem, replace the gas safety valve. This isn’t quick, easy, or cheap, but when the remaining option is to replace the fryer, it’s your best bet.

The combination safety valve can’t be removed without also removing some of the gas pipes. Therefore, find the nearest joints in the gas lines. Trace the lines to find them. Unscrew them. Then you can remove the entire device and its attached pipes. Once the safety valve has been removed, you can unscrew the pipes from the device itself.

To install the new combination safety valve, reverse these steps. Screw the pipes from the old unit that you just removed into the new combination safety valve and reinstall the entire unit into the fryer.

Before you screw in the new valve, be sure to wrap the threads with Teflon tape and to tighten the connections positively to minimize the chance of gas leakages. Reconnect the pipes and wires so they are in the same position as the old unit.

Preventing leaks in any compressed gas system is essential for eliminating product loss and keeping both the system and workers safe. Valves are one of the most common causes of gas leak and are often the leading area of loss through fugitive emissions. Fugitive emissions through valve leaks can lead to widespread product loss, adverse health effects, and even high levels of pollution. Unfortunately, preventing leaks in many different high pressure gas and fluid systems is not as simple as it seems. Compressed gas valves and liquid valves designed for leakage prevention must withstand a number of factors that can compromise other valves.

High pressure gas and liquid systems can often undergo a wide range of temperature changes, depending on the substances in the system and the environment itself. Traditional metal to metal valves can easily expand and contract with these changes in temperature. This effect allows high pressure fluids to escape from what was previously a tight seal. Another common cause of leakage in a high pressure system is mechanical vibration. Valves are often exposed to continuous vibration from nearby machinery. This vibration can cause the valve to slip and untighten. Unless these valves are closely monitored and repeatedly tightened, they can become an easy location for fluids to escape from.

At CPV Manufacturing, we design compressed gas valves and liquid valves to address these issues and prevent leaks. Our oxygen master control valves, gas filling valves, check valves, automated valves, and globe valves all incorporate design features that prevent expansion and contraction gas leaks and untightening through vibration. We design all of our compressed gas valves with reliability and durability in mind. The right high pressure valves can save you money on maintenance and replacement costs while also preventing the negative effects of fugitive emissions. Contact us today to learn more about leaks in high pressure systems and our specially designed master control valves.