Fire risk with Torches - Fire Inspector Question

Orchidians -

I just got a phone call from Richard, and he asked me the following question. I have no idea… can anyone shed some light on this issue?

See below.

I am a fire inspector with the City of Parma, Ohio Fire Dept. I’ve recently become aware of several jewelers in our city that use LP gas in their businesses. The Ohio Fire Code and NFPA limits the LP cylinder to the 2.5lb. (1 Kg) size for use inside of buildings that are accessible to the public. Some of these business owners have 15-30lb. size cylinders. I’ve visited your web site & found the section ‘How Are Torches Used in Jewelry Making?’ In this section the statement “The (LP) canister must be kept outside for safety reasons” was found. We are about to approach our business owners to advise them of this situation. We want to be sensitive as to how this will affect their business, and at the same time provide for the safety of all involved. They will have the option to use the smaller ‘hand torch’ size cylinders or move the LP gas tank outside under the proper conditions.
Can you provide any additional advice?

Thank you,
Richard Ciarrone
Fire Inspector
Parma Fire Dept.
(440) 885-1217x103 office
(440) 866-2418 fax

L.P. gas is heavier than air, so a leak can and will pool in low spaces, so
nearly all jurisdictions restrict the volume allowed in a structure.

Ron Charlotte
Gainesville, FL or

Hi Seth,

Possibly we can help. Our business, Paige Tools is ‘all about’ Tips & Torches for alternative fuel gasses, e.g., propane & natural gas. Safety issues, ‘misconceptions & truths’ about fuel gasses, etc. Everything dedicated to jewelry makers & the Torches / gasses they use… especially propane. Pass along our contact info and we’ll be glad to speak with the fire inspector.

Paige Tools, Inc.
PO Box 31055
Seattle, WA 98103

Hello Seth,
I agree with Ron’s reasoning regarding the size limit for interior propane tanks. It is great that the Parma, Ohio fire marshall wants to be so sensitive to jewelers’ needs! However, I don’t think it is a great imposition to ask that folks use the smaller tanks. It could prevent a hell of an explosion caused by pooling gas. After an oxygen regulator let go on my oxy-acetylene setup, I decided to go to a 1 lb propane tank and an oxygen concentrator running at 5 lpm. Few uses require more oxygen than this (maybe some rosebud tips), but if additional oxygen is needed, a 10 lpm setup or two ganged 5’s can be used. Since the concentrators are not for human breathing use, they can be found cheaply on the used market.

If buying 1 lb propane canisters gets pricey, it is possible to refill them from a 20 lb barbeque tank with an adapter. One of these adapters is called the “Schnozzle” and it costs about $8. If one settles for about an 80% fill, doing this is quite safe (done outdoors). The instructions are available on the Schnozzle website and elsewhere on the 'Net. Aside from a water torch, which has its limitations, this is about the safest setup I can think of.
Roy Kersey

Hi @PaigeTools and others - thanks for jumping in on this thread. I gave the inspector the URL of this discussion thread, and encouraged him to monitor it and reach out to anyone he likes directly.

Hello All,

Let me add a reminder about G-TEC Natural Gas Torch Boosters to raise utility natural gas pressure for excellent torch performance and workplace safety. Torch Boosters supply gas to the torch as it is used, there are no storage tanks, and you never run out. Natural gas is cleaner than propane or acetylene, the flame is not as bright so it is easier on the eyes and it provides plenty of heat, even for casting platinum.

G-TEC Torch Boosters are used by leading Diamond District jewelry manufacturers, retailers like the Jared chain and schools including North Bennet Street School, Fashion Institute of Technology and others. They are welcomed in all buildings in North America, even home studios and commercial facilities where propane cylinders are prohibited. More information is at

Ed Howard
G-TEC Natural Gas Systems

After much research and some trial and error, I now run my Meco midget and little torch in parallel on 1 lb propane, non-adjustable regulator equipped, tanks that I refill from a larger tank stored in my shed. The O2 is produced by a 10 lpm concentrator purchased used off the internet. It all works very well. I am up and running in no time and have no trouble working on the large 30 gram pieces that I make or melting 2 - 3 oz of silver for ingots. I now have regulators, flashback arresters, check valves, hoses, O2 tanks and other equipment stored in the same shed where I store the large propane tank. Look at my website ( for pictures. I sleep better knowing that I don’t have large compressed gas bombs in my cellar. I did pass this all by my insurance people and they are happy…Rob

Hi Seth,
After experiencing a natural gas explosion years ago, I’ve experimented with LP, hydrogen, acetylene, and have found value and issues with all. LP has the nasty habit of leaks laying low to the floor (heavier than air), so leak detectors, a common recreational vehicle component, are a must. LP and Diesel fuel have the habit of laying low and in pockets, the bain of boaters and RV’ers alike.
The other piece of equipment I now use is a simple back flow valve. Some counties require them. They address the issue of back burning, a phenomenon of the flame front being sucked down a line if the gas / oxy is shut down at the tank while the torch is still burning, rare, but I’ve seen it.
As of several years ago I started using MAP gas (there are several hybrids of this fuel) very controllable and available at welding supply centers. Better than LP, about the same for cost, hot enough to direct weld platinum with ease.
I’m bringing this up as an alternative to LP because the laws governing LP might differ from those applying to MAP. Those needing higher volume containers might have a viable alternative.
I’m not sure this is of value here but I wanted to throw it out there.

Hi Richard
I have a document which was posted several years ago here on the Orchid forum, so it may now be somewhat out of date.
It is the Torch Gas Guidelines for New York City Jewelers.
While the whole document is informative, Page 20 has some very specific guidelines on LPG and CNG (Compressed Natural Gas), which I think will answer your questions.
Unfortunately, i have not figured out how to attached a PDF file here, but I will email this document to you separately
Seth, If you could please advise how I can post this document to the forum it would be helpful.

Milt Fischbein
Calgary Canada

1 Like

MAPP is a modified propane formulation, and has the same issues as
regular LP gas as far as safety considerations are concerned. The model
code that most jurisdictions use is NFPA-30:

I guess I fail to see how putting the tank outside and running gas lines with all the connections that involves would be less likely to leak than the tank that sits next to my bench and has far fewer connections to fail. Propane is the fuel of choice for jewelry work. And the local fire inspector said nothing about my 30 pound propane tank but did insist that I put a chain around my oxygen tank so that it would not fall over. Anyway it would not be terribly expensive or complicated to set the tank outside and run a line into the building.

1 Like

Hello To All,

I want to comment on a statement in a recent posting:

“ The other piece of equipment I now use is a simple back flow valve. Some counties require them. They address the issue of back burning, a phenomenon of the flame front being sucked down a line if the gas / oxy is shut down at the tank while the torch is still burning, rare, but I’ve seen it.”

It is important to understand the distinction between backflow check valves and combination flashback arrestor check valves. Backflow check valves are designed to prevent a high pressure gas from flowing down a lower pressure pipe or hose. For example if a jeweler’s torch tip is blocked the higher pressure of the oxygen supply will overcome the lower pressure of the fuel gas and oxygen will flow into the fuel line and a backflow check valve will stop this.

However, if the tip is blocked and there is a flame in the torch then not only will oxygen flow the wrong way but so will a 5,000+ degree flame which will burn back to the fuel source, then explode.

The difference between a backflow check valve and a combination flashback arrestor check valve is that when the flame meets the backflow check valve it will melt the check valve and keep going to the fuel gas source, whether a cylinder or the utility gas meter. When the flame meets a combination flashback arrestor check valve the flame will be extinguished AND the flow of oxygen into the fuel line will be stopped.

Some jewelers believe they are protected by installing a simple check valve on their fuel and oxygen supply hoses or pipes…they are not. Only a combination flashback arrestor check valve puts out the fire.

Several years ago NYC Diamond District jewelers were literally exploding their utility gas meters because they were using city natural gas at less than 1/4 psi with oxygen at pressures between 5 – 70 psi and causing flashbacks. The NYC Fire Department and natural gas utility, Con Edison, did extensive research and testing to determine the cause and solution. They found that jewelers were not using flashback arrestors because the utility gas pressure was so low that the flashback arrestor blocked gas flow; jewelers could not light their torches. They also found that simple back flow check valves were insufficient to stop a flashback event.

The NYC Fire Code was revised to require jewelers using utility natural gas (“piped gas”) to have a pressure booster device capable of boosting natural gas to at least 5 psi and installing UL Listed combination flashback arrestor check valves on jewelers’ torches. G-TEC Torch Boosters were approved by the Department of Buildings and Fire Department for this application and are now required for all jewelers connecting their torches to the utility gas supply. More information about what the Fire Code requires for NYC jewelers is here:

Whatever the fuel supply jewelers should have a UL Listed combination flashback arrestor check valve on both the fuel gas and oxygen hoses or pipes; a back flow check valve will not protect you from a torch flashback.

Ed Howard
G-TEC Natural Gas Systems

If natural gas is an option for these jewelers, the suggested G-Tec concentrator is a very safe and efficient alternative. I have used that combination for years after finding the recommendations of the NYC fire department. - Judy Hoch

I agree with you that it still possible for propane from an outside tank to be released into your studio through the piping and connections. So in that respect keeping propane outside is only marginally better, but there are at least two other reasons to avoid keeping a 30 pound propane tank indoors…

  1. 30 pound propane tank is equipped with a safety relief valve. It is actually possible for the relief valve to pop open and release a large quantity of propane into your studio.
    This could happen if the propane tank is overfilled (especially in cold weather) and brought inside into a heated studio, or left in the sunshine by a window, the liquid propane in the tank expands and vapourizes and pressure starts to build up in the tank. The relief valve pops open and lets some of the propane out of the tank to lower the pressure inside the tank. Once the pressure in the tank drops to a safe level, a spring on the valve pops it shut. This works just fine if the tank is located outside as the tank manufacturer intended, since the propane gas will disperse harmlessly, but not so OK inside your studio.

  2. If a fire were to start in your studio and your propane tank was nearby, the tank would warm up and the safety relief valve would open and feed propane into the fire,

My personal preference is to use a 1 lb propane tank located in the studio beside my soldering station. I keep spare propane takns in a shed outside and away from my studio. My 1 pound tanks last for several weeks, but I do not do any casting/melting or anything that requires a lot of heat.

Calgary Canada

1 Like

Hi Milt
Thank you so much for that distinction.
It’s useful in many areas as I also mig /tig /& oxy /act. weld as well, yet still missed that one.

1 Like