Jump to content


Photo
- - - - -

Kiln gas type question


  • Please log in to reply
7 replies to this topic

#1 Brian Reed

Brian Reed

    Advanced Member

  • Members
  • PipPipPip
  • 195 posts
  • LocationWashington State

Posted 30 October 2012 - 04:33 PM

I was hoping to find an answer to this question.

I have an Updraft kiln that I purchased used. It was actually refurbished at SPS and thenbought by someone whom I purchased it from.

The kiln was setup to run propane when I bought it asreported by the previous owner, but he admitted that he never lit thekiln. I purchased it and went and boughta 100lb tank and some hoses to hook it all up. I have fired the kiln twice, but the main valve on the burners does not seemto be setup for high pressure Propane, but rather lower pressure naturalgas. I say this because it is barelyopen like 5% open in order to run the burners at the right level. And when I try to open the main value all theway and adjust the pressure from the propane tank the gauge on the propane tankdoes not read anything. Like it isrunning less than 1 PSI. If I run thetank at 2 PSI then the main valve seems to work as designed, with adjustmentsand an inline gauge which make sense.

I have run the kiln twice and the first time it ran well,other than the aforementioned incompatibility of gauges. It used about 4-5 gallons of propane to getto cone 10 and it worked great. Thesecond firing went ok, but I failed to get up to temp before the propane ranout. The propane bottle froze up andjust wasted hours of propane without getting up to temp. I saw it happening as I was firing, butthought it would just keep up if I continually adjusted the tank pressure.

My question is that having said all of that I can convertover to natural gas and I think the kiln will run better. It is small so the feed to a single applianceshould be fine. I have a gas line withan extra shutoff within 25 feet of the kiln now so plumbing in a new line wouldbe easy. IS this the right way togo? Also how do I tell if the venture burnershave propane or natural gas orifices? Isuspect they are natural gas and I have been attempting to run high pressure propanewhich caused issues.


Brian Reed

Throwing down in Washington State

http://www.reedpottery.com

Northwest Clay Club

#2 neilestrick

neilestrick

    Neil Estrick

  • Members
  • PipPipPip
  • 2,432 posts
  • LocationGrayslake, IL

Posted 30 October 2012 - 05:00 PM

Contact the manufacturer and see what size orifices the burners are supposed to have, then verify with their answer. Once your tank gets low it will want to freeze up. Better to fill it up after each firing if you continue that route. I'd go with the natural gas hookup if that works out. Typically, gas kilns need a lot of volume at low pressure, so check with the kiln manufacturer as to what size gas line they recommend for the kiln.

What type of kiln is it? A round top loading updraft?
Neil Estrick
Kiln Repair Tech
L&L Distributor
Owner, Neil Estrick Gallery, LLC
www.neilestrickgallery.com

neil@neilestrickgallery.com

#3 Chris D

Chris D

    Member

  • Members
  • PipPip
  • 13 posts

Posted 30 October 2012 - 08:30 PM

I was hoping to find an answer to this question.

Also how do I tell if the venture burnershave propane or natural gas orifices? Isuspect they are natural gas and I have been attempting to run high pressure propanewhich caused issues.



I'm pretty sure (from the reasonably extensive research I've done) that natural gas venturi burners for kilns have #28 orifaces. You can get a #28 drill from your local hardware store. If it fits, it's a natural gas oriface. If it is too small for the #28 drill, it's a propane oriface. We had propane orifaces on our burners and drilled them out for natural gas. Yet to see how that works, but I've read it's no problem.

#4 Mark C.

Mark C.

    Advanced Member

  • Members
  • PipPipPip
  • 2,614 posts
  • LocationNear Arcata Ca-redwood rain forest

Posted 30 October 2012 - 08:49 PM

Chris is on the right track above-its easy to get the orifices out and measure them-If the kiln manufacture is still around call them for this size- You can drill them out for natural gas or if they are set up with propane smaller size orifice or buy a new set from SPS . They are not very much$$ You need to determine what size they are with a numbered drill size.
Your problems to me sounds like your kiln is set up for natural gas which has larger orifices- The valves will work with either fuel. If you want to stay with propane which costs more to run get smaller orifices. Unscrew the cast iron burn tips and use a small wrench to unscrew the brass orifice back by the air flow collar . Measure one with numbered drill
If you want to stay with natural gas and are close to a source. Have a line run-what size is the kiln in cubic feet? That will dictate gas pipe size as well as length of pipe run.
et us know what you find out.
Mark


Mark Cortright
www.liscomhillpottery.com

#5 Brian Reed

Brian Reed

    Advanced Member

  • Members
  • PipPipPip
  • 195 posts
  • LocationWashington State

Posted 30 October 2012 - 10:06 PM

Thanks for the answers.


The kiln is about 20 feet from the gas line. The main like seems to be 3/4 or 1 inch, but for the appliances it seems a 1/2 in pipe is the norm. I assume that the 1/2" pipe woudl work fine. That the the pipe size on the main fuel in on the kiln now.

Yes I can go down to SPS and purchase new orifaces if needed. I will disassemble one of the venturis and check the size with the Natural gas ones. They are only $6 each as far as I can tell.


The kiln is 10cf hexagon updraft. The guy told me it was a Crucible, but not real sure as there are zero makings on it.

To get the whole thing all setup for natural gas I think it it will be a little over $100 so worth the risk. Then i will have everything to run it on Propane or gas depending on how I need to configure it.

Yes ai understand it does freeze up, but I was so suprised how it froze slowly when teh tank was well over half full, and then the kiln just sucked the gas without getting much hotter. Perhaps it already has nartual gas orifaces, but will check.



Thanks for the help.
Brian Reed

Throwing down in Washington State

http://www.reedpottery.com

Northwest Clay Club

#6 Mark C.

Mark C.

    Advanced Member

  • Members
  • PipPipPip
  • 2,614 posts
  • LocationNear Arcata Ca-redwood rain forest

Posted 31 October 2012 - 01:45 AM

I would suggest at least running 3/4 line to near kiln before necking down to 1/2 inch.
If it a crucible its made in Seattle if my memory serves. SPS can tell you everything about this kiln-take a photo of it and ask them.
My 12 cubic updraft has a 1/2 inch line for two feet before upsizing to larger 1 inch.
Is this a 4 burner model? 3 inch wall thickness?
Mark
Mark Cortright
www.liscomhillpottery.com

#7 dave the potter

dave the potter

    Advanced Member

  • Members
  • PipPipPip
  • 33 posts
  • LocationNorth Augusta SC

Posted 31 October 2012 - 11:38 AM

There is no one size orifice for natural gas or propane. You need to know how large the kiln is and how many BTU's per cu. ft. it will require to attain the desired temperature. With that information you get a flow chart(most kiln building books have them in the appendex or you can get them thruogh whatever gas company you use). The chart will tell you the orifice size given the BTU's/hr and the BTU value of the gas. Not as complicated as it sounds but will give you correct result.

#8 Brian Reed

Brian Reed

    Advanced Member

  • Members
  • PipPipPip
  • 195 posts
  • LocationWashington State

Posted 31 October 2012 - 12:50 PM

Mark - Thanks for the advice on the pipe size, I will see if the 3/4 will work here, I suspect it will be fine. Yes it is an SPS kiln, but to be honest I do not really want to even talk to them as their customer service has been so poor lately. I think it will end up being a frustration for me. It is a 4 burner model, with a single main valve with Baso shutoff device, and a ring pilot setup.



Dave - Thanks for the information, I was not aware of that, as in the SPS catalog they call out only two orifices, one for propane and one for natural gas. Perhaps since this is a crucible kiln and SPS is the maker then these should be compatible.

Thanks.
Brian Reed

Throwing down in Washington State

http://www.reedpottery.com

Northwest Clay Club




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users