Propane compatible thermo couple

[Kent]

Looking to add a thermo coupler to my propane forge in case of flame failure

Anyone got an old propane boiler or space heater they don't want that I could rob one off - or other ideas?

 

[Stueeee]

if the flame is going to be enclosed you could use a photocell like oil burners have. Link the photocell to a gas solenoid with an override button switch to press when you light the flame.

 

[CompoSimmonite]

I thought thermocouples worked on heat expanding a liquid inside a pipe that then pushed against a cut off. That means unless you need some sort of extra high temperature capable item any will do and CNC just the same as propane.
http://www.screwfix.com/p/standard-...rch-_-SearchRec-_-Area1&_requestid=161730#_=p

You then need the actual valve -
http://www.gasproducts.co.uk/acatalog/Type_50_FFD_Flame_Failure_Valve.html#aHA550

With shopping around / eBay I'm betting you can get a complete set up of everything required for under £20 including delivery

 

[hunter27]

I thought thermocouples worked on heat expanding a liquid inside a pipe that then pushed against a cut off. That means unless you need some sort of extra high temperature capable item any will do and CNC just the same as propane.
http://www.screwfix.com/p/standard-...rch-_-SearchRec-_-Area1&_requestid=161730#_=p

You then need the actual valve -
http://www.gasproducts.co.uk/acatalog/Type_50_FFD_Flame_Failure_Valve.html#aHA550

With shopping around / eBay I'm betting you can get a complete set up of everything required for under £20 including delivery

No fluid involved just a small current of electrickery created by heating the hot junction.
pete

 

[Kayos]

You will need the complete fsd and Gas valve

 

[brightspark]

u would need the gas valve as well an

You will need the complete fsd and Gas valve

with jet to suit propane on the thermocouple hot end

 

[ronan]

Isn't the k-type thermocouple the most versatile and widely used ? We used them to monitor temps in an uninsulated room before and also used them in ovens/kilns. Worked really well.

 

[daleyd]

Isn't the k-type thermocouple the most versatile and widely used ? We used them to monitor temps in an uninsulated room before and also used them in ovens/kilns. Worked really well.

They are but I think the ones needed are different. Although they are commonly called thermocouples they are really a thermo electric valve.

The k type you mention are proper thermocouples, used to measure temperatures rather than a safety device.

 

[Stueeee]

Would the boiler style thermocouples continue to work OK in a main propane flame? the only ones I've come across are heated by a pilot flame in domestic appliances.

I've had to replace a couple of burnt out thermocouples in boilers and water heaters in days gone by where someone had turned up the pilot flame to stop gusts of wind etc. blowing the flame out.

 

[Kent]

Was told by an ex gas engineer it needs to go to a propane compatible gas valve. Though he never did lpg

So hence looking for one off a lpg boiler or space heater

 

[Kayos]

The gas valves are different to stop liquification of the gas inside the control, I have a boiler with a Honeywell valve in the back of my van but it's NG