Gas safety valve is a thermomagnetic control used to shut off the gas flow to the burner in the event of a pilot outage. The Grayson/Robertshaw TS-7, nicknamed the “Pickle”, was a common oven safety valve model used in stoves and heating units produced in 1940s-1950s.

It’s not a valve like the ones you can turn on and adjust to control the gas flow to a cooktop burner. This one is simply opened or closed, under the control of a thermocouple. If the thermocouple is heated enough by the oven pilot flame, it generates a voltage that will keep the safety valve open allowing the gas to flow to the oven burner whenever the oven thermostat is turned on.

If the gas flow to the stove is interrupted, the pilot flame extinguishes. Lack of voltage closes the safety valve. That’s when that juicy little red button gets involved. When it’s pushed in, the valve opens. With a pilot flame heating the thermocouple, a working thermocouple can keep the safety open.

It’s a simple valve to set. Get the pilot flame going. You push in the red button, wait to give the gas a chance to reach the oven burner and ignite. Then release the button. If all goes well, the safety remains open. And you’re done.

If the oven flame extinguishes, there could be a small number of conditions that cause the problem. Best first approach is to consider the thermocouple. Check to see the sensor end is bathed in flame. A common problem is the thermocouple, which is like a battery, has died and needs to be replaced.

Next in line for a possible problem would be the safety valve itself. The safety valve’s magnet depends on thermocouple’s voltage.  But if the magnet weakens, it’s time to replace the valve.

Since they are intended to be rarely accessed, safety valves can be mounted in out of the way places in the stove. If you are unfamiliar with your particular stove, and can’t locate the safety valve right away, follow the gas line from the thermostat.

Pickle TLC

Just to make sure I maintain my weird stove lady street cred; I share what I did as an instant gratification project.

I managed to trek to my barn today since enough snow melted. Rummaging thru some still unpacked boxes of OKM stove parts, I came across this woefully neglected ‘pickle’ safety valve. It screamed for some TLC.

I scrubbed the exterior with a wire brush and SuperClean. Since the red button would not budge, I added a couple of drops of Tri-Flo around the base of the button, heated it with a heat gun. After a few minutes of pushing/releasing, the button is probably as springy as when the safety was new!

That’s what I call fun!

The Insides

Care to see the inside? See that little gizmo with the coil spring? That’s the heart of the safety. It’s a solenoid, a gas safety valve magnet mechanism that responds to the thermocouple’s voltage. Gas flows into the valve at the front opening. If the solenoid is in one position, gas can pass thru and out the back opening. In the other position, it blocks the flow.

Here is a modern functional equivalent of that gas safety valve magnet mechanism. Question: would that modern unit work properly in the old pickle? 😀