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Torches, Gas Products, Safety Issues & Best Practices

Torches , Regulators , Disposable Cylinders , Gasses, Safety Issues & Best Practices are areas of interests to most jewelry makers. Discussions involving these topics often come up on Orchid. Paige Tools believes operating gas equipment correctly & ’safely’ are areas most fine jewelry makers should become informed about First . That conviction motivated us to write this post reviewing the above products plus underscore areas we consider most important. The ‘First Skill’ …Gas products knowledge & safe Torch use.

Paige Tools makes specialized Tip products for many, popular Torches. We also have years of experience in other products mentioned at the beginning of this post. Our Tip products are designed for Propane & Natural Gas because we believe they are the Best Choices for most precious metal work . We also do testing using acetylene & hydrogen for some processes.

Side Comment: Hydrogen / oxygen is an excellent choice for platinum casting with it’s high heat and super clean flame but it should Not be used for working on palladium or palladium alloy white golds. Palladium has an affinity to absorb hydrogen potentially causing it to become brittle.

The Little Torch, Meco Midget & Hoke , often mentioned on Orchid, are great Torches for basic Bench work . Cost & construction quality differ between these Torches & others but those 2, points are Not as important for effective Torch work as Tips designed to the fuel gas used … something we stress again & again. Matching Tip design with the fuel gas being used significantly improves the performance of all Torches . Unfortunately, single orifice Tips that come with most Torches are Not correct for Propane or Natural Gas. Any Tip design will ‘light a flame’ but to realize the potential of a flame such as highest heat output, flame stability, etc., Tip design is Key! We explain this in more detail in our Newsletters and to people calling for Tech help.

Disposable Oxygen Cylinders: Most people we’ve spoken with who have used Disposable oxygen cylinders, for jewelry making, consider other (oxygen) options fairly soon due to high cylinder cost & limited run time. Disposable oxygen cylinders only contain a small amount of oxygen. More oxygen is also used than fuel gas during typical Torch work which contributes to oxygen running out faster than a fuel gas. Additional details below…

Oxygen from Refillable Tanks has some advantages over other oxygen sources but also some drawbacks! Oxygen tanks are pressurized to about 2000 PSI. Thick, tank steel walls allow that pressure. Disposable Cylinders (oxygen & fuel gas Disposables) have very thin walls. Oxygen pressure in new, Disposables is limited to about 400 PSI which reduces the amount of gas they can contain. Oxygen from both refillable Tanks and Disposable Cylinders is over 99% pure oxygen . Higher purity oxygen allows producing the hottest Torch flames with all fuel gasses.

Oxygen Concentrators have become very popular as a convenient option. The oxygen they generate generally runs in the 90-95% purity range from newer machines in good operating condition. One drawback of Concentrators is fairly low output pressure. Very popular 5/LPM Concentrators typically output around 6 PSI. Even 10/LPM units with double the oxygen volume output only increase output pressure about 1 PSI.

A Concentrators basic function is removing Nitrogen from the ambient air. Nitrogen composes about 78% of the air we breath. Pure oxygen composes roughly 20% of air. The remaining components of air consists of H2O (water vapor), CO2 & micro amounts various nobel gasses. Concentrator filters remove most, not all, of the nitrogen which accounts for the 90-95% oxygen purity they produce. The other 5-10% of gas from a Concentrator is made up of the substances noted above.

To protect Concentrator filters from becoming contaminated by fuel gas backing up in a Torch (something that can happen) then flowing down the oxygen line to the concentrator a Check Valve should be installed on the Concentrator output. This is a one-way valve allowing oxygen out of a Concentrator but blocking any gas from going back into the Concentrator and contaminating its filters. A Check Valve is a very inexpensive product to protect a Concentrator used in a Torch setup. More on Check Valves below…

Disposable (camp stove) Propane cylinders are very economic , low cost with a good run time. Propane is filled as a liquid in all sizes of propane cylinders & tanks… hence the term LPG, Liquid Propane Gas. Propane pressure (PSI) inside containers varies depending on the temperature of the container typically determined by ambient air temperature around the container. At 30 F pressure inside a propane container is about 50 PSI. At 80 F almost 130 PSI increasing in pressure (PSI) as the container temperature increases. Propane automatically changes between a liquid and gas state based on its temperature; a process called Vaporization . Conversion back to a liquid state from the gas state is called Liquefaction and depends on temperature & pressure in the container. A few basics about this great, fuel gas that’s safe to use when standard storage, use practices & regulations are followed.

Natural Gas is piped to US residences at about ¼ PSI (very low pressure; higher pressure to commercial buildings). If piped to a home or studio this clean burning fuel gas could be the good option. It produces a somewhat lower temperature flame than propane & oxygen but is still plenty hot enough even to do platinum bench work. Fewer Torches are able to use NG at it’s very low or typical delivery pressure without a NG Booster. Google G-TEC for information on their NG Boosters. Again, ANY Torch using NG or Propane will benefit form Tips designed for those gasses.

Acetylene: Combined with ‘Tanked’ oxygen it is the ideal fuel gas for Torch welding Steel but overly hot for jewelry work . Its flame is also too concentrated & Not as clean burning as propane or NG. Acetylene is also not as safe a fuel gas as many people may assume. Google: 15 PSI warning about acetylene! Information to keep in mind when choosing fuel gas options.

Disposable Cylinder Regulators: Most have have 1 function… they reduce gas pressure from the Disposable cylinder high pressure to a fixed , low output pressure in a single Step or ‘Stage.’

Traditional Regulators have 1 or 2 pressure Gauges and are more robust built than Disposable Cylinder Regulators. One, gauge indicates gas pressure of the source gas. A 2nd gauge shows output pressure to the Torch for units with 2, gauges. A very handy feature of most traditional Regulators allows adjustment of the output pressure over a wide, range indicated on the 2nd Gauge of a 2, gauge Regulator.

These Regularors come in various models. Single stage models drop high pressure of a gas source in 1, Stage / Step just like Regulators used on Disposable cylinders but Traditional models are far more robust. Think of a ‘Stage’ as a ‘Step’ in pressure reduction

Dual Stage models drop the pressure in 2, Steps. A 2, Step reduction stresses regulator components far less than dropping pressure in 1, Step providing a much longer Regulator life span.

New , Single Stage models work fine at holding low output pressure settings used for typical Torch work but as the Regulator ages set pressure will begin to creep up or down and must continually be readjusted.

Dual Stage models are able to hold the low output pressure settings over long periods. Mainly used in commercial industry, medical & laboratory environments Dual Stage Regulators are much more expensive then Single Stage models

Traditional Regulators also come in several levels of Construction Quality referred to as Light, Medium & Heavy duty. Component materials inside a Regulator are the primary factors determining the duty level roughly indicating how long the regulator should last with average use. All duty levels work fine with all refillable oxygen and refillable fuel gas tank sizes.

Regulator Take Away: Paige Tools recommends Light or Medium duty, Single Stage models . Costs of Heavy Duty & Dual Stage units, in our opinion, do not bring enough benefits to justify their cost. Well respected brands like Victor, Uniweld, Harris & Smith are well respected across US industries. Note: You Do Not need to match Regulator brands for fuel gas & oxygen sources. Mix & match is commonly done.

Arrestors are ‘Good Practice’ (safety) products to use. An arrestor should be attached to all, Fuel Gas and Oxygen Regulators used on Disposable Cylinders & Refillable Tanks. Typical Arrestors sold today include both Flashback protection + a Check Valve . Often advertised as a Flashback Arrestor ask the seller & read the included literature to see if a Check Valve is part of the Arrestor.

On an Oxygen Concentrator just a Check Valve is good practice as noted above in this post. The Flashback function reduces gas pressure a little, about 1-1.5 PSI . A Check Valve does not reduce pressure . Oxygen from a concentrator output is typically low pressure so maintaining its output pressure is usually important. Since Flashback protection is not really needed with an oxygen Concentrator only a stand alone Check Valve is used.

Regulators used on Disposable Cylinders generally have enough PSI output to compensate for the small, PSI pressure drop of the Flashback function.

Arrestors Take away: Arrestors are not a ‘required’ product for Torch operation but are Good, safety devices to use!

Torch Practices: Most small hand Torches used by jewelry makers were designed to have limited gas volume throughput. They work great for typical soldering & annealing duties but for casting & larger ingot melts a ‘next size up’ Torch really helps. Torches like the Smith AWIA, Victor J-28, Uniweld 71, etc., with robust, professional construction & greater gas volume throughput plus the Correct Tips allow faster melts. Only slightly larger in size than common bench Torches for casting operations they are the way to go. Our Tips support all these Torches. See this Bike Frame Builders link on our website. We don’t sell the above Torches but do show good photos of the 5, most popular models and the correct Necks to use.

Becoming confident using a Torch involves understanding a variety of operations… The simple / correct sequences of turning on/off a Torch and gas sources, How to adjust a fuel gas / oxygen flame to reducing, neutral & oxidizing profiles plus basic maintenance of Torch & the gas products being being used. Product knowledge and Good Practices are part of the First Skill mentioned at the beginning of this post. This combined know-how is a Big assist building user confidence & overall Torch expertise. Give us a call if you have questions. (206) 527-1515 Our hours of operation on paigetools.com.

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Hello Paige Tools!
Thanks for this great summary regarding torches, regulators, etc. I’m going to note one thing here that differs a little from your info…my current Invacare Perfecto2 five lpm oxygen concentrator only provides ~5 psi, but the Devilbiss Drive 5 lpm model produces 8.5 psi…so if you are planning on using a concentrator but want a little more pressure for rosebud tips and metal melting, you might want to look for a concentrator with a higher psi rating…and maybe a 10 lpm model, too. -royjohn

i love my paige tips. working with NG and a 5 concentrator…asking about check valves. what is the one i need? and it goes between the torch and the oxy concentrator?

Hi royjohn!
Thanks for your feedback. Some of the info we posted was meant to be general and apply to ‘most’ users vs. getting too detailed. What you said about the Devilbiss units re: psi needs is just part of the ‘need to know’ digging into more detail. Even with fixed psi units gas volume & oxygen purity do not remain the same when output volume is adjusted. A big assist in melting is having high oxygen purity to make a hotter flame. I believe the oxygen purity range DeVilbiss notes is about 87% to 95%. Increase oxygen output volume for a big flame and oxygen purity decreases as does potential flame temperature. All factors… psi, volume & gas purity are important. Thanks again for your information.

Hi jmdw,
Thanks for your kind words re: our Torch Tips.
You asked about a *Check Valve with your setup. Because you mentioned using
Natural Gas I’ll expand a bit on that too.
Try WesternEnterprises.com. for a Check Valve. Look at the CV-30R & CV-7R units on their site. The Valve is mounted on the output of your Concentrator. You may have a short, pigtail of PVC tubing from the Concentrator ending with 9/16-18 RH fitting where the Valve would screw on? Call Western & explain what oxygen output fitting you have. Check Valves are low cost.
About your NG line:
We just touched on Natural Gas with a quick, mention of a NG (pressure) Booster in our earlier (long) post. If your incoming NG is typical residential pressure, about ¼ psi in the US, that’s not enough pressure to open a Check Valve installed in the NG line. Most Check Valves need about 2-3 psi to open. Possibly you’re using a NG Booster with a traditional Regulator connected to the Booster output? That setup then allows using an more traditional Arrestor on the Regulator output that has both Flashback & Check Valve functions. If no Booster then only an Arrestor without a Check Valve could be used and the incoming NG line. The NG source coming into your studio would not be protected from oxygen possibly getting into the NG source line that a Check Valve is designed to prevent.

I thank you, the check valve info is just what I need. I do have a pressure booster (G-Tech) for the
nat gas. that’s what was necessary for my homeowner’s insurance to ok my set up

jmdw in asheville,nc

Hello,

quick question: are your new MX melting tip, and MA rosebud tip compatible with oxygen concentrator/disposable propane) use?

julie

FYI: some general information:

02 concentrators work by absorbing nitrogen from air using a zeolite molecular sieve. Zeolites are aluminosilicates that are porous, and made synthetically now, to contain a specific pore size to act as a nanofilter. Under higher pressure, nitrogen is absorbed, leaving behind 02. Lower pressure purges the nitrogen and regenerates the zeolites. The concentrators cycle between high and low pressure to maintain absorptive capacity. Check valves to prevent back flow of hydrocarbon gases are essential since these gases will plug up the pores… the zeolite filters are good for 4-6 years, before needing to be replaced. C02, other gaseous contaminants will eventually " poison" them requiring replacement.This mostly pertains to medical 02 concentrators that are continuous use.

Pressurized acetylene gas is spontaneously explosive even in the absence of oxygen or air. Triple bonded carbon is unstable…acetylene cylinders are filled with a “sponge” that is saturated with acetone. Acetylene is dissolved in acetone, which stabilizes it and prevents degradation. Methyl acetylene sometimes is substituted for acetylene as it is safer and more stable. Becareful not to drop, bang, or store acetylene bottles near heat or outside in the sun! A double regulator is essential for both high pressure 02 and C2H2…the first stage tells you the remaining bottle pressure which has to be reduced before passing thru the second stage regulator which is at a much lower pressure.

MAPP gas is a mixture of methylacetylene and propadiene… these two gases spontaneous convert back and forth between them, with methyl acetylene being thermodynamically favored… MAPP gas Pro is propane./propadiene… it burns at a lower temperature in air than methylacetylene/ propadiene.

Pressurized natural gas at 1-10 psi burns at a high temperature, both with air and oxygen… 10 psi torches are expensive ($1000)…they work on the venturi principle to create higher pressure at the nozzle…boosters are far cheaper and compress the natural gas by pumping, but usually work in the 1-3 psi range.

I have used both acetylene/air torches and oxyacetylene torches for specific purposes. Most of the time cheap disposable propane cylinder torches from any hardware store suffices for annealing, soldering and general purpose work for silver and gold… acetylene/air torches are hotter burning and can make working with gold and silver general purposes easier. But acetylene is expensive. Oxyacetylene is useful for melting for pouring into ingot molds… metals can be superheated for a good pour. the air/fuel mixture has to be controlled carefully… an oxidizing flame has an excess of 02 and will burn out copper in an alloy creating oxidation…a reducing flame has too much carbon in it. It burns at a lower temperature but is messy…My oxyacetylene setup was initially bought to cut thin steel plate for heavy duty mobiles and windchimes…and some welding but MIG welding was far easier to do than gas…I have a small one also…

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