Heat-Activated Gas Shutoff Valve?

jyl · jyl's Garage

I am looking for a device that will shut off a 1" gas line when the heat at a remote probe location exceeds a certain level. A fire safety device, basically. I'd put the probe at or above my range and use it to automatically shut off the gas supply line to the range in the event of a fire.

I've searched using various keywords, but not turned up anything. Well, I have found inline valves that snap shut when exposed to enough heat to melt a fusible link. But that would requiring routing the gas line directly through the location of a potential fire, which seems inconvenient and counter-intuitive.

Anyone know of anything like this?

FYI I have found devices that automatically shut off a water supply line when a remote sensor detects moisture. Cost about $100. Seems useful for water heaters, dishwashers, etc. Haven't researched them much but I chatted w/ someone who swears by them. FloodStop Stops Water Damage

MotoSook · 11-10-2009, 10:14 AM

What's your budget? What operating pressure? Do you need it to control temperature or just shut-off then require manual reset?

turbo6bar · 11-10-2009, 10:15 AM

Gas furnaces have a limit switch in the plenum. It turns off the gas valve when temps exceed 180 degrees, if I am not mistaken. Most limit switches are pre-set during manufacturing, but some older switches are adjustable with small tabs on a rotary dial. This would be easy to install inline with a gas valve. The switch is closed during normal operation and breaks to open when temp hits the limit. You would also need a relay that would break and hold open when triggered by the switch. This would keep the gas valve from turning off AFTER a potential fire is out and temps fall below the limit.

MotoSook · 11-10-2009, 10:37 AM

I don't know how remote your sensor is relative to the valve. Don't know what temperature range or pressure range you're working with. Don't know if you'll need electrical or gas (pneumatic) actuation of the valve, or if you want a spring to close valve with a remote controller to hold it open. Don't know what safety features you need....

But you'll likely have to piece this together without spending a lot of money.

You can probably get a temperature switch, a relay and a solenoid valve cheaply. Then wire it all together. A normally closed solenoid valve, energized to keep open via the relay and a normally closed switch would work. If you ever lose power to the solenoid, it would close the valve. If your circuit is compromised (short or failed temperature switch), it would close.

Be sure the pressure rating on the valve meets your conditions. If you need manual reset, get a locking relay.

Lots of possible solutions.