Propane/02 set up

I have been using oxy/ acetylene for years with Smith little torch
I am switching over to propane / oxygen.
1. Can I use my oxygen regulator from my acetylene setup in conjunction with my victor propane regulator.
2. Do I need to purchase a flashback arrestors with check valve?
3. I have smith check valves from my oxygen/ acetylene setup. Can I use them?


1 Like

Hi Cathy,
At Paige Tools we often hear the same questions you asked. Your questions directly relate to the products we produce (Special Tips & Torch products for propane / natural gas) plus the services we provide. Our Answers below:

1. Yes, you may use your oxy Regulator. Regulator ‘Brands’ do not need to be the same in a Torch setup. This applies to both traditional style Regulators and Regulators used on Disposable cylinders.

2. There’s an important distinction between ‘need to’ and ‘should use’ with regard to Flashback Arrestors & Check Valves. Both are safety products that ‘should be’ used where appropriate but neither product is ‘needed’ (or required) for a Torch system to ‘work.’ Typical Flashback Arrestors sold today also contain a Check Valve. Stand alone Check Valves are also available and good to use where a Flashback Arrestor is not ‘needed’ such as on an oxygen concentrator.

3. You did not mention your oxygen source?
If using a Refillable oxy Tank or Disposable oxy cylinder use a traditional Arrestor that contains both a Flashback function & Check Valve. A traditional Arrestor would also be used with both a Refillable propane Tank & Disposable propane cylinder.

You said: ‘smith check valves’ …do you mean Smith ‘Arrestors’? You may use the same Arrestors for your propane / oxygen setup. If safety devices are old or subjected to a flashback issue in the past then consider replacing with new ones. Give us a call with any questions. (206) 527-1515


Cathy…Before we go into a lot about this topic, please review the archives as this subject has been covered extensively in the recent past. Once you have, post specific questions resulting from your review…Rob

1 Like

Thank you Paige tools!

I’ve been reading a lot about flashback arrestors and would like to add them to my system. However I’m a little confused. Been trying to find arrestors for propane and can’t really find any. Can I use one for acetylene on a propane tank? Or do I need one specifically for propane?

1 Like

Richard…I see diagrams that show flashback arrestors installed at the regulator end of the hose and others that show them at the torch handle end of the hose. There is similar confusion for where to install check valves. Where should they go? Thanks…Rob

Regulator side.

Arrestors used with common jewelry making Torches (Little Torch, Gentec, Meco & Hoke) plus a few other small size Torches Flashback Arrestors are screwed onto the Regulator output connector. Scott, mentioned that too. More details below re: attaching safety devices like Arrestors & Check Valves.

A Check Valve is connected (in series) with the PVC line coming out of a Concentrator. Concentrators that have been ‘slightly’ modified by resellers may have a 9/16"-18RH (male) connector attached to the Concentrator Cabinet for the Torch oxygen line. (RH = right hand threading). B size, Check Valve would screw onto the Cabinet Connector. The oxygen line from the Torch then screws onto the other end of that Check Valve.

Commercial Torches typically have threaded connectors on the Torch body where gas lines screw on. The Little Torch and a few other small Torches come with gas lines attached to the Torch body. The Hoke has barbed fittings as part of the Torch body to attach push-on gas lines. Professional / commercial Torches have threaded connectors on the Torch body. A Flashback Arrestor or Check Valve could be attached (screwed on) directly to the Torch body rather than to the Regulator if the user wanted.

Direct attachment of safety devices to a Torch body vs. to a Regulator stops a Flashback flame at the Torch… not allowing a flame to run down a gas line to the Regulator. ‘Sometimes’ welders using very large Torches with oxy/acetylene setups even ‘double-up’ attaching a Set of Flashback Arrestors to both gas line Connectors on the Torch body ‘plus’ a 2nd Set of Arrestors on both Regulators. Way overkill for small, jewelry making Torches!

Note: The *Meco comes with threaded connectors on the Torch body to screw on gas lines. Tapered, barbed connectors are available that screw onto the Torch body connectors so (push on) gas lines like PVC tubing or other hose materials can be used. Even with these options safety devices would still be attached to Regulator(s) with Meco Torches.

S_ Palmer asked about Arrestors… Not a specific one for ‘propane.’ Buy an Arrestor for Fuel gas (e.g., propane, acetylene, hydrogen, etc.) or for Oxygen. The main difference between Fuel gas & Oxygen Arrestors are the Connectors on the Arrestor. Fuel gas Connectors have LH (left hand) threading. Oxygen Connectors have RH threading. All Fuel Gas Connectors on Arrestors, Check Valves & Torches have notches cut into each Hex Nut corner. Oxygen Connectors do not have notches on their Hex Nuts.

I have always run the arrestor at the regulator and check at the torch handle. My logic is that the arrestor keeps a flame front from reaching a tank and the check keeps gas from migrating in the wrong direction in a zero pressure situation. I have seen diagrams that suggest the reverse. For those of us who use concentrators, either device does cause a pressure drop in an already low pressure system…Rob

Rob, I want my posts to be both understandable and consistent on what I’ve said earlier re: Arrestors & Check Valves so I’ll repeat some things here plus add a few extra details & info.

#1 : A Check Valve is Not considered an 'Arrestor.'
#2: Typical Arrestors sold today contain ‘Both’ a Flashback stop function + a Check Valve. I’ll bet that’s the type of Arrestor you have. Because Flashback prevention is not always appropriate but a Check Valve may be, such as with an oxygen Concentrator, ‘stand alone’ Check Valves are used.

Not to put too fine a point on things but details can matter. I try to be fairly complete in what I write intending to follow-up when necessary. My intention anyway.

Arrestor & Check Valve subject matter is fairly easy to understand when fully explained. Only talking about parts of a Torch (protective) system, especially to those unfamiliar with these products, their terminology & how products work can be confusing at best. ‘Full understanding’ often (usually) requires revisiting subjects several times, explaining something in a different way, using new examples or adding more detail to make things clearer.

#3. When I speak about Arrestors I mean products that contain Both a Flashback stop prevention function + a Check Valve.

Small size Torches are beneficial for jewelry makers. Adding an Arrestor to a Torch handle makes the Torch heavier, possibly unbalanced and is unnecessary with common jewelry making Torches. Most jewelry Torches could not have an Arrestor added to the Torch handle anyway. because there are no threaded, gas line connectors on the handle to screw on an Arrestor. The Meco is an exception that does have threaded connectors on the handle although one or two attached Arrestors to it’s small, handle would be odd, to say the least for typical soldering work being done. A casting operation using a Large, commercial (welding type) Torch running high gas pressures is a case where a Set of Arrestors added to the Torch handle may be beneficial.

#4. For most jewelry makers using small, hand Torches attaching an Arrestor to a Regulators output is the correct way to go.

#5. Your comment re: “zero pressure situation” and Check Valves… I’ll explain differently. Zero pressure is possible but unusual. **You are correct re: the purpose of a Flashback stop & Check Valve function. Exactly how the Flashback is stopped is fairly simple but for another discussion if of interest. Again, Check Valves prevent the reverse flow of a gas (or a liquid) in a system from mixing with another gas or liquid.
If you’ve seen diagrams that indicate the reverse, as you said, or something else they are incorrect …or possibly not explaining something clearly.

Example of a situation more likely than ‘zero pressure:’ The fuel gas source (I’ll use a propane Disposable for example) runs very low on propane. Propane output pressure becomes very low… lets say around 3 PSI. Oxygen coming into the Torch at lets say 5-6 PSI. The Torch Tip has become clogged from spattered solder, other debits, etc. Oxygen coming into the Torch might overpower the low pressure propane entering the Torch. Without a Check Valve in the propane line (any fuel gas) or an Arrestor that contains a Check Valve nothing would prevent oxygen from flowing into the propane Disposable! A major safety issue. Same thing if using a refillable propane Tank or any other fuel gas container.

Any fuel gas getting into an oxygen Concentrator without the protection of a Check Valve on the Concentrator output is a different problem. Any fuel gas will contaminate the Nitrogen filter(s) in the Concentrator and stop it from producing oxygen. A real pain to clean the Nitrogen filter(s) or at worst $ to replace the nitrogen filter(s).

#6. The Flashback stop function of an Arrestor ‘Does’ create a small, pressure drop as gas passes through. The Check Valve inside an Arrestor, or a separate (stand alone) Check Valve, ‘does Not’ drop pressure.

Extra info: Check Valves have a ‘Cracking’ (opening) minimum pressure / PSI depending on the specific Valve product.

The Check Valve Paige Tools suggest using on an oxygen Concentrator opens at about 1.5 PSI, way below the oxygen PSI coming out of Concentrators. Oxygen will easily pass through the Check Valve with No pressure drop.

Because of very low Residential delivery pressure of Natural Gas (NG) in the US, about ¼ PSI, a Check Valve will not open & NG would not get to the Torch. A gas pressure Booster would be required to increase NG pressure.

Trying to run a Torch on Residential delivery PSI NG… that’s too low to open a ‘stand alone’ Check Valve is a Safety Gamble! It’s possible oxygen coming into the Torch from any oxy source (Concentrator, Disposable oxy Cylinder or Refillable oxy Tank) to get into the home natural gas system, because of the same potential Torch blockage issue explained above …a NG + oxygen scenario you Do Not want. Using a NG Booster pressure of the NG is increased to about 25 PSI. Then, a traditional Regulator can be attached to the Boosted NG output. (Remember, a standard Arrestor has both a Flashback stop function + Check Valve). The booster option for NG is expensive but because it allows the use of a traditional Regulator gives good safety protection.

Please Call us with questions. (206) 527-1515


Richard…You are correct that my current flashback arrestors also have a check valve built in. My original ones did not. I have removed the combo flashback/checkvalve temporarily from my O2 concentrator to see if I got any more O2 and that seemed to be the case based on the size of the flame that I was able to maintain, but not enough to take the chance of removing it permanently. I would only need that extra capacity for large melts of melting brass or copper. I am researching propane melting furnaces to melt larger quantities of copper and brass as well as propane forges for annealing, hardening and tempering steel. Do you have any suggestions? As always, thanks for your great information…Rob