what is the safety device in an oven?

[bluesky]

Hi guys I am studying gas safety theory now. Just have a silly question.

Normaly what is the safety device in an oven, liquid expansion valve or thermocouple? or either is possible? when I looked an oven how can i identify it is liquid expansion valve or thermople because they are so similar. Also how to test the safety device in an oven?

thanks a lot,

 

[mikegas]

You can tell the difference by the way the oven comes on, a thermocouple will come on at full rate and a liquid expansion will come on at low flame. You test a thermocouple by doing a tightness test then light the oven, once lit isolate the gas supply and wait to hear the click of the solenoid valve reseating within the max required time (60 sec), carry out another tightness test there should be no change from your first tightness test. To test a liquid expansion you light the oven which should come on at low flame wait for it to go to high flame then isolate the gas supply then wait for 60 seconds max and re light the oven the oven should light at low flame if it lights at high flame then its failed and is ID

 

[g60rge]

so an oven with a liquid expansion device doesnt shut off the gas therefore not needing a tightness test?

 

[REDSAW]

i would read/study your book as it is all there.
these questions are asked many times in your acs.

 

[mountainman]

One way to tell is if you have to press and hold a button or knob to get gas to flow then its a thermocouple, if you don't then it is a mercury vapour valve.

 

[quality]

Please explain how the safety device on my oven works

I call it the wife but I am sure there is a fault somewhere

 

[gasmarc]

how long have you got LOL