Propane gas line hookup

[MFP]

As Usual, I am a little confused. In reading the Olmpic manual, it says to attach the firing ring to a 3/4 inch black pipe gas line....So.....do you attach a hose with a regulator to the other end of the gas line? They recommend 20 feet between the propane tank and the kiln. I would appreciate knowing how other people have set up their propane feeds. This is for an Olympic 2831 kiln.

Thanks!

Marie

[Mark C.]

Most propane kilns use hard piping betwen the tank and the the kiln-If its underground-our local propane company uses copper lines to get close(underground) then steel pipe topside to kiln.If its all topside then steel pipe is the way to go-also its usually smaller diameter as propane is higher presures than natural gas .Say 3/4 pipe size .

[MFP]

Thanks Mark but how do you attach a solid pipe to the propane tank? I won't be using a propane service....just a 40 gallon tank.....you must use a flexible hose but in the pictures it looked to me like the regulator was right before the gas ring. Any ideas?

[Bill Kielb]

I think it depends on your design and what is acceptable by code. Codes are created to make things safer for the mass common application. So flexible gas appliance connections are  generally limited to six feet in length, now mostly stainless steel and single flare connections. They allow the appliance to be moved in and out and maintain their integrity for many years. This takes into account the low operating pressure (less than 1 PSI), wall thickness of the flexible tubing, and pressure drop that will occur in this flexible connection.

 If your kiln is permanent or semi permanent, hard pipe to a fixed location near your tank with the final connection between tank and pipe being flexible. Some states accept copper, virtually all accept black steel pipe and there are some that require stainless steel piping or tubing.

For  above ground  vapor service in a permanent or semi permanent appliance location  black steel pipe likely is fine from the kiln rigidly mounted and adequately supported to a point near where your tanks will be. Likely Worst case your state would  require seamless tubing.  Black pipe is nice and certainly has sufficient wall thickness but in PSI pressure ranges must be adequately joined and pressure tested to ensure no leaks. This is a tough subject actually, in the State of Illinois high pressure natural gas vapor service must be fully welded construction and tested. We can however use newer cross linked (rated plastic) service gas line underground in many circumstances as this is designed to be impervious to corrosion and often carries a tracer wire in it so electronic location is possible in the future. Same problem with fiber optic cables btw, no way to find them after they have been buried for years.

Perhaps  the easiest and safest way for you to do this would be to have a licensed plumber do the hard pipe from kiln to a location where your tanks may be in accordance with local codes. Have him pressure test after completion ( often a one day  leak down test),  then attachment to the tank would be an approved propane tank flexible o ring connection just like a gas grill. In the meanwhile the regulator and isolation valve would be hard piped into this line near the kiln, per code, to comply with available service (shut off) requirements of the appliance under code and to ensure the burners have 11” of pressure to them (I think that was their max. rating). So at the kiln a service shutoff (usually within six feet), regulator, then operating valve would likely be the configuration. Generally a pressure gauge downstream of the operating valve is standard so the operator can see the adjustments.

I suspect most folks just run flexible hose from their tank and declare their kiln as non permanent. My further suspicion is this will be permanent and therefore not per code and technically not able to use the flexible hose start to finish.  Now put wheels on the kiln and you likely have a whole other argument.

Actually  pretty complicated stuff and we haven’t even talked about running piping for liquid propane delivery when tank vaporization rates cannot keep up. (Frosty tank)

Seems like hire a reputable licensed plumber is likely the best answer!

[MFP]

Thanks Bill. I live in Idaho....so I would be in the non permanent category.  I doubt these people have ever dealt with a kiln and as such would dream up a million reasons not to approve anything.  Having built a kiln previously, black pipe and I are old friends. I do have a very good plumber....but I don't know about his familiarity with this particular process. My plan was black pipe attached to the fire ring and then a flexible hose from the tank to to black pipe.....that junction is what I am most concerned about because obviously the tank will have to be disconnected at times to be refilled. So, I need to talk to him about a way to do that that results in a safe re-hookup each time that is safe. The poor guy---I have already had him do a couple of other difficult jobs for me over the years...I bet his cringes every time he gets a voicemail from me.  I have decided that gas fires are going to be winter fires. The kiln will be located in a 24 x 36 shop with a garage door and one of those huge sliding doors.....both of which will  be open during the firing to exhaust heat, gases, and keep the temp in the building down to normal levels as well as providing O2 for the fire.  Until I have an idea of the heat generated, I think this is the best plan.  I am not going to get into the nightmare of building a hood for it to vent through the roof. I have my doubts about their assertion that a double wall pipe will dissipate the heat enough going through the roof.  I think it's actually safer to do it the way I am panning. 

[Bill Kielb]

13 hours ago, MFP said:

Thanks Bill. I live in Idaho....so I would be in the non permanent category.  I doubt these people have ever dealt with a kiln and as such would dream up a million reasons not to approve anything.  Having built a kiln previously, black pipe and I are old friends. I do have a very good plumber....but I don't know about his familiarity with this particular process. My plan was black pipe attached to the fire ring and then a flexible hose from the tank to to black pipe.....that junction is what I am most concerned about because obviously the tank will have to be disconnected at times to be refilled. So, I need to talk to him about a way to do that that results in a safe re-hookup each time that is safe. The poor guy---I have already had him do a couple of other difficult jobs for me over the years...I bet his cringes every time he gets a voicemail from me.  I have decided that gas fires are going to be winter fires. The kiln will be located in a 24 x 36 shop with a garage door and one of those huge sliding doors.....both of which will  be open during the firing to exhaust heat, gases, and keep the temp in the building down to normal levels as well as providing O2 for the fire.  Until I have an idea of the heat generated, I think this is the best plan.  I am not going to get into the nightmare of building a hood for it to vent through the roof. I have my doubts about their assertion that a double wall pipe will dissipate the heat enough going through the roof.  I think it's actually safer to do it the way I am panning. 

Double wall pipe is fine for gas service if and only if this is just a  natural draft hood that will draw dilution air along with the kiln fumes. Additionally For reduction the hood must be mounted high enough so the flames never impinge on the metal. So yes, if using double wall pipe the hood must be designed to not exceed 500 degrees of which btu and stack height will be the primary drivers of the equation. Even when we design these we always test at top temperature with an infrared device to make sure we got our assumptions correct.

[MFP]

Thanks Bill. Somehow opening the doors seems  a much better plan than a hood. Especially in the winter here where the heat will be instantly sucked out the door. I am talking a 14 foot high sliding door and a standard garage door. I got the kiln moved and situated yesterday....I found an appropriate direction to run the pipe where it will not be bothered.  I did find something very interesting which might pertain somewhat to the other gentleman's problem....the burners are not placed on the exact points of the shelves. I also noted that you have to measure all around the outside of the shelves to make sure you have the same amount of space between the shelf and the walls all around. It was somewhat tedious but obviously necessary....sometimes there was a post adjacent to the burner and sometimes not. It's going to make for a very interesting flame pattern. Since the shelves are separated by one inch, there are three posts per shelf. I used the 1.5 posts because of all the weight those posts are going to have to take. I completely re-arranged the studio yesterday. Since the young man I was going to be teaching has disappeared, I did not need to have it set up for two people to be throwing.  My materials are showing up Monday. I have to get my pickup cleaned out....the bed if full of locust branches. Hopefully they can set the pallet in the bed and I can just drive it back there. I don't like having to depend on other people to do things for me. I got the major stuff moved...I can manage the rest.