Olympic Gas Kiln Sitter Option

[ThruTraffic]

Does anyone know where on might purchase the Kill Sitter kit for gas kilns?

This Kiln Sitter is 120v electrical outlet powered and has a relay that cycles a gas shutoff valve once max temp is reached.

Talking to Clay-Kin and Olympic and it appears that is no longer an option for their kilns (even thought all their product catalog photos show their Torchbearer kilns with a Kiln Sitter installed).

[Dick White]

It appears that some of the photographs on the Olympic website show a kiln sitter device on certain models that presumably operated similar to one in an electric kiln, in that a sitter cone inside would bend, causing the flap to drop, which would trigger something to cause a valve on the main gas line to close, and thus turn off the kiln. However, the sales material only offers an optional electronic control, based on a Bartlett 3-key controller that, that as indicated in the instruction manual, will absolutely shut the kiln down at one of 3 predetermined temperatures (1700F, 2000F, or 2350F) should it overfire.  But there is also some noise a few pages later that one can program a single set point as the shutoff temperature of one's choosing (though if you understand ceramic firing, you will know that an absolute temperature and a cone are two very different concepts), plus a hold time at that temperature. So, I would guess that notwithstanding the pictures, the kiln sitter option is obsolete and was replaced by the controller.

[Mark C.]

Did you call Oylmpic?about this as they will know whats up best.

 

[neilestrick]

I would think that a sitter wouldn't last long in a reduction atmosphere, considering that the sensing rod and cone supports are metal. A digital controller would be better, because it would also display the current temperature. You could build your own system pretty easily if you're somewhat handy with pipes and electricity. A high temp shutoff is a great thing to have as a safety, but I would use watching cones on the shelf and manual shutoff as the primary method when firing a gas kiln.

[ThruTraffic]

16 minutes ago, Mark C. said:

Did you call Oylmpic?about this as they will know whats up best.

 

I used their contact form. No response yet. If none tomorrow, Monday, I’ll call them. I stay away from the phone as much as possible. I also found another Olympic vendor that alludes to the kiln sitter option but they’re closed till tomorrow.

[ThruTraffic]

6 minutes ago, neilestrick said:

I would think that a sitter wouldn't last long in a reduction atmosphere, considering that the sensing rod and cone supports are metal. A digital controller would be better, because it would also display the current temperature. You could build your own system pretty easily if you're somewhat handy with pipes and electricity. A high temp shutoff is a great thing to have as a safety, but I would use watching cones on the shelf and manual shutoff as the primary method when firing a gas kiln.

An LT-3 is a couple hundred bucks. The high limit controller is over $1000.

I have an old Amaco test kiln with an LT-3 and it’s been working cutting power on and up to cone 10 for probably 30 years. 

I opened up my LT-3 and saw how silly simple it will be to make it work for gas shutoff when the cone triggers. All I’ll need is a gas valve with an actuator that keeps the flow open until it’s power supply drops. Olympic just sees more profit in the $1000 controller is the only reason they stopped installing the LT-3 I’ll bet. Buyer beware.

[Bill Kielb]

1 hour ago, ThruTraffic said:

valve with an actuator that keeps the flow open until it’s power supply drops. Olympic just sees more profit in the $1000 controller is the only reason they stopped installing the LT-3 I’ll bet. Buyer beware.

High limits are usually certified devices so their price often seems silly high. Some folks circumvent this (right or wrong)  using less costly high limit devices ($100.00 range) but users design in redundancy so multiple high limits daisy chained and  wired  in a fail safe fashion. Regardless of high limit, gas kilns generally should be fully supervised and the firing manually terminated when appropriate.

It’s easy to come up with a powered gas valve to control the on/off function but consider this: since the 1980’s  gas fired appliances have required dual redundant gas valves for 100% shutoff. So if you do this, redundant safety and redundant valves have been the established norm for some time now.

[neilestrick]

1 hour ago, ThruTraffic said:

An LT-3 is a couple hundred bucks. The high limit controller is over $1000.

I have an old Amaco test kiln with an LT-3 and it’s been working cutting power on and up to cone 10 for probably 30 years. 

I opened up my LT-3 and saw how silly simple it will be to make it work for gas shutoff when the cone triggers. All I’ll need is a gas valve with an actuator that keeps the flow open until it’s power supply drops.

A kiln controller itself is $350 or so. A complete digital controller system for an electric kiln is $1000 because it includes a lot of parts- controller, relay, transformer,  box, power cord, outlet, etc, plus labor to put it all together. Plus it's not just a high limit shutoff. It has a ton more functionality than a manual kiln with a Sitter.

To use a Kiln Sitter on a gas kiln it's not just the cost of the sitter. $200 for the Sitter, $250 for a pair of solenoids, plus power cord, wires, conduit, sitter housing, plus all the labor to assemble it.

1 hour ago, ThruTraffic said:

Olympic just sees more profit in the $1000 controller is the only reason they stopped installing the LT-3 I’ll bet. Buyer beware.

Most kiln companies don't use Kiln Sitters any more, or even offer them as an option. They're old technology, not very dependable, and don't have the functionality of digital systems. And their longevity on a gas kiln would be questionable due to the reduction atmosphere.

If you want a high temp shutoff for a gas kiln, your best bet is to build your own. A system intended for an electric kiln is overkill. I've built several gas systems using Watlow CV high temp shutoff controllers which are only about $165 and they work very well. The cost would be about the same as building a system that uses a Sitter, and it would last longer and be safer.

In addition to the shutoff system, gas kilns should have a pilot system as well, that shuts the kiln off in the even of flame failure. For simplicity, Baso pilot valves are a good way to go.

[ThruTraffic]

8 minutes ago, neilestrick said:

A kiln controller itself is $350 or so. A complete digital controller system for an electric kiln is $1000 because it includes a lot of parts- controller, relay, transformer,  box, power cord, outlet, etc, plus labor to put it all together. Plus it's not just a high limit shutoff. It has a ton more functionality than a manual kiln with a Sitter.

To use a Kiln Sitter on a gas kiln it's not just the cost of the sitter. $200 for the Sitter, $250 for a pair of solenoids, plus power cord, wires, conduit, sitter housing, plus all the labor to assemble it.

Most kiln companies don't use Kiln Sitters any more, or even offer them as an option. They're old technology, not very dependable, and don't have the functionality of digital systems. And their longevity on a gas kiln would be questionable due to the reduction atmosphere.

If you want a high temp shutoff for a gas kiln, your best bet is to build your own. A system intended for an electric kiln is overkill. I've built several gas systems using Watlow CV high temp shutoff controllers which are only about $165 and they work very well. The cost would be about the same as building a system that uses a Sitter, and it would last longer and be safer.

In addition to the shutoff system, gas kilns should have a pilot system as well, that shuts the kiln off in the even of flame failure. For simplicity, Baso pilot valves are a good way to go.

1000% disagree.

[Bill Kielb]

21 minutes ago, neilestrick said:

In addition to the shutoff system, gas kilns should have a pilot system as well, that shuts the kiln off in the even of flame failure. For simplicity, Baso pilot valves are a good way to go.

Ahh, the cost of safety, measured in dollars or lives lost / changed and of course potential liability for makers if their safeties fail. An interesting question would be: does any major manufacture produce new kilns with kiln sitters as a  primary means of shutdown on them anymore or is that control fairly obsolete? Even with the backup shutdown timer built in.

[Dick White]

I will stay out of the discussion on how to make one for the lowest price as I am not a gas tech, but if you are looking to retrofit another gas kiln with the Olympic part, I would be very surprised if they would sell it as a separate unit. There is just too much liability surrounding amateur installation of gas valves and burners. JMO, YMMV.

[ThruTraffic]

Olympic replied and they do still sell the LT-3 Kiln Sitter option; for $600.

A new LT-3 can be had for less than $200 and I'm guessing a actuated valve is probably less than $50.

Each of those prices are retail which means Olympic can get them both for probably less than $100. Hefty markup.

I got my answer to the original question. Thanks folks.

[neilestrick]

12 hours ago, Bill Kielb said:

An interesting question would be: does any major manufacture produce new kilns with kiln sitters as a  primary means of shutdown on them anymore or is that control fairly obsolete?

Sitters are obsolete. I don't know of an American kiln company that currently offers the Sitter as the primary safety system. Maybe as a custom build, but not as a catalog item. Some used to offer sitters as a backup to the digital system, but most don't do that any more, either. Dawson, who made the Sitters originally, went out of business several years ago, presumably because everyone was using digital systems instead. Skutt bought them out in order to provide parts, but even they don't offer them on their kilns any more. Digital systems are easier to use, easier to repair, offer far more functionality, and are less likely to over-fire.

In just the last week I've had two customers who have been firing their kilns for years without understanding that the backup timer on their Sitters has nothing to do with how long a firing takes to get to temperature.

[Mark C.]

You can still order a Skutt with a sitter I think with a timer backup (thats two systems for shut off) I know this was true a few years ago as I know someone who did.

 (In just the last week I've had two customers who have been firing their kilns for years without understanding that the backup timer on their Sitters has nothing to do with how long a firing takes to get to temperature.)

Well thats just because firing is an unknown for many ,many people.