Problem: regulator or flashback arrestor?

[hoboglass]

I've scanned through bunches of posts trying to find enlightenment but...

Prior to yesterday I had been using my propane with a closed torch pressure of 7psi. I decided to turn down the psi a smidge because some of my beads came out looking a bit sooty (could have been dirty glass but I decided to try a slightly lower psi). So I turned down the regulator about 1/10 or 1/8 of a rotation before I turned on the propane yesterday. And when I turned on the propane I had NO psi on the line. Tank pressure, yes. Line pressure, no. I tried the torch just to make sure that it wasn't a faulty regulator reading but no propane was coming through.

I should mention here that my torch (a piranha) is connected to 25 foot 1/4" ID copper tubing going to a flashback-quick connect combo that goes directly into my regulator. I disconnected and reconnected the quick connect from the regulator: no go. I changed propane tanks. Nope. I took a wrench and took the flashback-quick connect off the copper line then remounted it. No change. Finally, I used a wrench to remove and reconnect the flashback-quick connect from the regulator and --voila-- problem solved.

Except that I don't know if I have a regulator problem or a flashback arrestor problem or if I should just take the flashback arrestor off the system all together. Any thoughts?

[MikeAurelius]

The Pirahna is a surface mix torch, and you really don't need a flashback arrestor for it -- that being said, I'd say that the FBA is probably defective.

Are you leaving your pressure set on the regulator when you turn off the tank? If so, that's a problem. You need to back off the regulator T handle so that there is no pressure on the feed line side of the regulator, then turn the tank off. Failing to do this will cause a diaphragm failure of the regulator.

The diaphragm is only a thin piece of rubber and it is not designed to handle a high pressure in-rush of fuel gas in a set-pressure tension state. Always back the T handle off when shutting the gas off and remember to bleed the line so that no pressure remains.

[Dale M.]

Also it takes a certain amount of pressure to keep check valves in quick disconnects open.... Did you up pressure at regulator to what it was previously and try it?

Dale

[hoboglass]

Thanks so much, Mike and Dale, for your suggestions. I had tried to pressure up but still had no flow so I'm going to take off the flashback arrestor and see how things go.

This is the first time I had heard about turning off the T handle...one of my local welding guys told me to "set it and forget it"...hope I haven't ruined the regulator as well.

On a related note, the T handle thing makes me wonder if we might have a problem at the school where I teach: we have a long (maybe 50+ feet) run to a 12 torch manifold. We never turn off the propane at the tank, never touch the regulator, only use the inside shutoff valves, and never bleed the lines (too big a volume of gas)...could we be damaging our regulator there too? Our propane does fluctuate pretty dramatically sometimes. (I realize that all this sounds pretty dangerous but the decision of how and when to shut things down is not my call).

[MikeAurelius]

Terrie -- what you are describing is possibly the single most dangerous thing I've ever heard of.

If it were me, I'd be doing everything in my power to stop that practice immediately, even to the point of discussing it with the school administrator. This is a violation of basic safety practices and needs to be stopped immediately. If there were ever a fire in the facility and the only thing stopping the flow of propane were a couple of shut off valves...let's just say those shut off valves won't stop a fire. There would be a burn through on a pressurized propane line and the fire would become practically unstoppable. This is also an insurance violation for most commercial installations, and the school is risking its insurance by allowing the practice to continue.

[Dale M.]

Originally Posted by teankisi

....one of my local welding guys told me to "set it and forget it"...hope I haven't ruined the regulator as well.

Not the brightest guy at welding shop.... Everybody I have been in contact with in welding indiustry advocates bleeding down torch and removing pressure off regulator diaphram when shutting down after days work...

On a related note, the T handle thing makes me wonder if we might have a problem at the school where I teach: we have a long (maybe 50+ feet) run to a 12 torch manifold. We never turn off the propane at the tank, never touch the regulator, only use the inside shutoff valves, and never bleed the lines (too big a volume of gas)...could we be damaging our regulator there too? Our propane does fluctuate pretty dramatically sometimes. (I realize that all this sounds pretty dangerous but the decision of how and when to shut things down is not my call).

At a minimum the line from tank to manifold should be hard metallic piping (if it is not already) and each line off manifold should have its own shut off valve (so if there is problem at one station, it can be isolated).... Also there should a master shut off valve on hard line where it enters building with large sign, "EMERGENCY GAS SHUT OFF"", labeling it........

As Mike says, very dangerous as it is now.....

Dale

[Peach Blossom Beads]

Ok. Sorry to hijack. I used to do this correctly, according to Dale's instructions. I'm confused now.

So, when shutting down, I go outside and turn back the regulator (off) and THEN shut off the tank. Then go back in and open the torch valve. Then go back out and turn the regulator back on to bleed the line, then turn it back to off??? YES?? Am I missing something? Is the only way to do to go back and forth a couple of times? Do I have it in the right order?

Thank you.

[Dale M.]

To shut down system. Tank off first........ Bleed or burn off fuel...... Back off regulator......

To fire up system. Open tank valve, set regulator, normally with fuel valve open at torch (if torch valve closed, use about 2-3psi more than desired pressure) fire up torch and work....

Dale

[Peach Blossom Beads]

Thanks Dale. That's exactly what I've been doing. I just go shut off the tank, let the line bleed, and then close the regulator. This thread totally confused me. I thought I was breaking my stuff!

[ziggys]

Hijacking again. Mike wrote you don't need a flashback arrestor with a surface mix torch. What is the difference between a surface mix, verses a dual, propane/oxygen torch
We need flash-back arrestors for say a Mini CC, right?
Really showing my ignorance.
Angela

[Dale M.]

There is two oxygen/fuel torch types, internal mix and external (surface) mix.

A internal mix mixes fuel and oxygen in barrel of torch (mixing chamber) and is forced out tip where it is ignited ( National 3A and all welding and cutting torches). Since fuel and oxygen is already mixed it is susceptible to combustion in mixing chamber by a flame front passing through tip and igniting mixture in mixing chamber and cause a explosive flame front that can travel back up hose.

A external mix or surface mix torch mixes fuel and oxygen after it leaves barrel of torch and is mixed and combusted on "surface" of torch(Mini CC- Bobcat - minor - and more) .

A external mix torch is next to impossible to flash back because fuel and oxygen mix and combust in the free air space in front of torch barrel. The fuel and oxygen are delivered to torch face in individual oxygen and fuel passages. its almost impossible get a flame front to pass through face of torch as passages are filled either pure fuel or pure oxygen and will not sustain flame front.

Dale

[ziggys]

Originally Posted by Dale M.

There is two oxygen/fuel torch types, internal mix and external (surface) mix.

A internal mix mixes fuel and oxygen in barrel of torch (mixing chamber) and is forced out tip where it is ignited ( National 3A and all welding and cutting torches). Since fuel and oxygen is already mixed it is susceptible to combustion in mixing chamber by a flame front passing through tip and igniting mixture in mixing chamber and cause a explosive flame from that can travel back up hose.

A external mix or surface mix torch mixes fuel and oxygen after it leaves barrel of torch and is mixed and combusted on "surface" of torch(Mini CC- Bobcat - minor - and more) .

A external mix torch is next to impossible to flash back because fuel and oxygen mix and combust in the free air space in front of torch barrel. The fuel and oxygen are delivered to torch face in individual oxygen and fuel passages. its almost impossible get a flame front to pass through face of torch as passages are filled either pure fuel or pure oxygen and will not sustain flame front.

Dale

Thanks for the explanation. Sounds like the surface mix torch would be about the safest way to torch. I was planning on buying a Mini CC and was quoted the price of 2 flash-back arrestors by the seller. One for the propane and one for the oxygen concentrator. Later I was told I don't need one for the concentrator by someone else. Any ideas why they would try to sell me a set? Unless of course they are just being sales people.
Angela

[Dale M.]

Some people use flashback arrestors because it makes then feel totally safe, some use them because they believe they are necessary, some don't use them because the don't care or better educated to their use....... Some sellers believe you need them so they push them. Some suggest them, some will explain that the are not necessary. In end its buyers choice if they want them or not.... Though I feel they are not absolutely necessary on surface mix torch, but if it makes you feel safe, by all means use them. And YES I DO suggest you use them on premix torch. IF you do decide to get them get type that mount at torch, this not only protects regulator, the will protect hose too.

Dale

[SL Beads]

I am glad I saw these threads because I was just about to send pm to one of you experts. I am having problems with my regulator and this is the second time in a short period of time. I use Carlisle MiniCC and 10lb-tank. My flame started to fluctuate, like every five seconds flame becomes huge and shrinks down to very tiny. The regulator needle goes up and down accordingly. So, I thought the regulator was broken. I took it in for repair and got a new one at the same time because I wanted to work while waiting for the repaired one to come back. I was using this new one for awhile, like four months, and guess what? The new one is doing the same fluctuation dancing now. I thought this was too strange. But I could not think of anythng that might be causing this. So I took out the first regulator that came back from repair and thought I would take the second one to repair. However, the one that was supposed to have been repaired is not right either! One thing that is different this time, though, is that when I opened the tank valve all the way the regulator needle did not move at all. Usually it goes up to 800lb mark. I thought that was odd. But, anyway I tightened the T-bar and lit the torch. The flame came alright, so this proves that the tank is open despite the regulator indication. I thought of taking two regulators back to the store to be repaired and buy the third one while waiting. Then, I saw these threads and got me thinking. Maybe I have been doing this whole thing wrong. My regulator has a combination flashback arrestor and quick disconnect. When I am done each day, I turn off my concentrator first, then the propane tank. I burn off the fuel in the line and when the flame is gone totally I back off the T-bar of the regulator. I am tempted to try Mike's method today before I take my regulators to the shop, ie, close the torch valve, back off the T-bar, then shut off the tank and finally bleed at the torch. My fear is that I already damaged the diaphragms of my two regulators? Any input from any of you will be greatly appreciated. Sachiko L.

[ChrisCamac]

Some of things I will write will completely contradict the advice of others in this thread. Please understand that my company is a manufacturer of torches and automated machinery using torches, and I have been with them for over 10 years, currently heading up sales, R&D, automation developement, and other hats that aren't relevant. As such I am intimately familiar with the innerworkings of the torch, gas and oxygen use, industrial codes, etc. Of course, most of what I will state below is educated opinions, so in the end you must make your own decisions. I would never tell someone that they have to buy anything, but I will recommend what I think is best for their setup and situation.

Flashback Arrestors in use with pre-mix torches: Becuase the gas and oxygen are combined, prior to exiting the torch, there is a high chance of flashback occuring. In most cases, this flashback will not travel any further than the torch itself. In severe cases, the flashback will travel into the supply lines and possibly to the tanks. Wherever your flashback arrestor is in the line is the only place you can say definitively that a flashback arrestor will not go any further than this point. Flashback arrestors are highly recommended for pre-mix torches, and in some cases are required by codes.

Flashback Arrestors in use with surface mix torches: The fuel gas and oxygen are completely separated in this kind of setup. Therefore, a flashback occurence is rare. However, you must understand that if the torch is faulty, or if it gets dropped, shipped, banged, or otherwise damaged, then the small metal peices that separate the two gasses can leak. If they leak, you are just as likely, if not more likely to have a flashback. Flashback Arrestors are a safety device, like an insurance policy in a way. If you choose not to use them, that is your call. Please do not fault myself or any other supplier for recommending them simply becuase you do not beleive in a "in case of" kind of situation.

Flashback Arrestors / Fire Checks in use with natural gas: Most folks are aware that a flashback arrestor will not work with natural gas. This is because the pressure of the natural gas in your home is roughly 1/4 of a pound of pressure and the flashback arrestor requires 1 pound of pressure as a minimum to operate. There is a device that can work with natural gas and that is a fire check. The fire check, which Carlisle manufactures, is the only device I am aware of that can provide flashback protection for a natural gas line that is under 1 pound of pressure.

Flashback Arrestors and oxygen concentrators/generators: Although there is not a significant danger involved in not having a flashback arrestor on a concentrator, the flashback arrestor still can provide protection to your concentrator investment. Should a flashback travel to an oxygen generator, I am not quite sure what would happen, but I do beleive that it would have a good chance of damaging the concentrator in some way. Therefore, you are protecting the concentrator unit from harm should you choose to use a flashback arrestor with it.

Regualtors and fluctuation issues: This is a common problem that is usually seen as the torch "breathing" or changing its flame size rythmically every few seconds or so. The most common cause of "breathing" is the propane regulator. If you see the needle moving up and down slightly in time with the torch, then you have diagnosed your regulator as being the problem. The issue here is that many regulators are either cheaply made, or have a very large scale (0 - 100 or 0 - 200) which is just not what we as flameworkers are looking for. We want to run anywhere as low as 2 psi up to maybe 15 psi. When you set the regulator that is meant to be between 0 - 100 to say 2 psi, you are really testing it's quality limts. It most likely cannot find 2 psi consistently, so it hovers between 1 and 3 psi (this is known as "hunting"). How do we solve this problem? The easy way is to purchase a regulator more suited to the job, such as a 0 - 15 (the smallest I have found) from a good manufacturer (not made in China). The best way however is to use two regulators. One at the tank that is set around 15 psi and one at the torch that is set to your desired delivery pressure. This method is called dual regulation, and is the only way to ensure you do not have "hunting" or "breathing".

The original post in this thread: I think that each of your peices of equipment were working fine, but the flashback arrestor should be removed and replaced. I have heard of a situation like yours before, although it is rare and I cannot say with certainty how it occured. Here is my theory. The flashback arrestor works by sensing a pressure difference from the inlet side to the outlet side. I beleive the threshold of that differnce is 10 PSI. Your flashback arrestor saw that difference somehow (i.e flashback occured, pressures spiked, faulty arrestor perhaps) and shut down flow. You were not able to re-establish from through this unit until the flashback arrestor reset. Once you unhooked everything and put it back together you said that it started working again, which may indicate that until the pressures were fully released on both sides of the unit it could not reset. Bottom Line: Get a new set of flashback arrestors and install them, or just remove them from your setup if you would rather not use flashback arrestors.

Shutting down your tank and regualtor set: Leaving your tanks on when you are not using them is dangerous, will destroy regulators, and pretty much you just shouldn't do it. I suggest that you shut off the tanks first, then bleed your lines, then turn out your T handle on the regulators. This ensures that all the pressure, even that on the feed side of the regulator is gone.

[MikeAurelius]

Bottom line: if you have a surface mix torch, they are not necessary, but if you feel safer using them, no one is going to stop you.

[ChrisCamac]

Originally Posted by MikeAurelius

Bottom line: if you have a surface mix torch, they are not necessary, but if you feel safer using them, no one is going to stop you.

Your statement is quite simply incorrect. If you have a surface mix torch, flashback arrestors are not required to run the torch, but you WILL be safer using them. This is not a subject of opinion and is a fact.

[MikeAurelius]

As a manufacturerer, you *HAVE* to say what you did. As an independant safety writer, I can freely write as I wish based on my experience and that of others.

Do you have proof of your statement, showing how many surface mix torches have backflashed in the past 30 years and caused a tank explosion? By my count, NONE AT ALL.

This speaks quite strongly to me that flashback arrestors on a surface mix torch are about as useful as a veriform appendix in a human being. And based on the the post that started this thread, can cause more problems than they resolve ON SURFACE MIX TORCHES (caps for emphasis, not shouting).

You will get no disagreement from me on the requirement for flashback arrestors on premix torches. But I will argue to the ends of time itself that they are not necessary for surface mix torches.

[Islandgirl]

While we're on this subject... I have the old style regulator on my propane tank... no dials at all. Instructions when I got it in '94 JIm Kervin's original spiral bound book) were to set it and leave it... and that's just what I've done... I might add since it has no dials that it is a real pain to set. On the other hand it's held the pressure through many moves and hours of usage... Comments???

Also I'm buying a Smith 'little torch' for jewellery I don't have flashback arrestors on my lines now, I'm hoping to run it off my concentrator and aforementioned propane... I'm thinking I should put an arrestor on my propane if I'm going to add this torch into my 'harness'... RIGHT??? I've had jewellery torches flash back into the handle a couple of times, do they need the arrestor on the line?

Lynne

[bhhco]

Originally Posted by CarlisleGuy

....I am intimately familiar with the innerworkings of the torch, gas and oxygen use...
....

Thermochemical reaction and physical constraints question... what is the minimum volumetric size of a propane 'flame' (at 1g) before the reaction cannot be sustained in 1) a pure oxygen atmosphere, and 2) a air atmosphere?

Me

[ChrisCamac]

Originally Posted by MikeAurelius

As a manufacturerer, you *HAVE* to say what you did.

I have to say what I did because it is a fact and may help to save someone's life someday. I do not make these statements to sell torches, flashback arrestors, or any other product. If I stopped working for Carlisle today, I would still argue these points the same way.

Originally Posted by MikeAurelius

As an independant safety writer, I can freely write as I wish based on my experience and that of others.

Considering AuraLens is a supplier of torches, glass, safety glasses, and other items, I am not quite sure how you would consider your opinion to be as an "Independant" safety writer. Which is a large part of the problem. Your opinion weighs in more heavily than I beleive you realize. For you to post in a Safety Forum that, using flashback arrestors in surface mix torches only makes you "feel" more safe, is a disservice to the flameworking community. Consider that someone you influence could someday be hurt by your words (literally).

Originally Posted by MikeAurelius

Do you have proof of your statement, showing how many surface mix torches have backflashed in the past 30 years and caused a tank explosion? By my count, NONE AT ALL.

By your own words, I am a manufacturer. So I suppose I have seen more instances of these kinds of issues than yourself.

- I have seen a surface mix torch have a flashback, the hoses blew off the unit, and the hose spewed flame like a fire breathing dragon. The user in this case had his hair and shirt caught on fire. He suffered 3rd degree burns on 40% of his body. Counting in my head the other cases like this one where a hose burst or burnt through on a surface mix there are 13 cases in 10 years that I can recall.

- I have seen a surface mix torch with a hole burnt through the side of it that came from a fire within the torch. Actually I have seen that 3 times in 10 years.

I will not name those companies or individuals involved, as that would be inappropriate and damaging to others.

You are right though... I have not had any experience where the tank blew up. However I would consider the above examples to be "dangerous", don't you.

[ChrisCamac]

Originally Posted by bhhco

Thermochemical reaction and physical constraints question... what is the minimum volumetric size of a propane 'flame' (at 1g) before the reaction cannot be sustained in 1) a pure oxygen atmosphere, and 2) a air atmosphere?

This question is certainly outside the range of my knowledge. The question you have asked can be answered by online sources such as http://www.jstor.org/ , but it is largely irrelevant to the flameworking world or combustion theory in the scope of Carlisle's burners and applications.

If anyone wants to ask a question that is relevant to flameworking, perhaps another thread would be in order, as this goes way beyond hi-jacking a thread... more like hi-jacking it, driving it off-road, and burning it to hide the evidence.

[bhhco]

Originally Posted by CarlisleGuy

This question is certainly outside the range of my knowledge. The question you have asked can be answered by online sources such as http://www.jstor.org/ , but it is largely irrelevant to the flameworking world or combustion theory in the scope of Carlisle's burners and applications.

If anyone wants to ask a question that is relevant to flameworking, perhaps another thread would be in order, as this goes way beyond hi-jacking a thread... more like hi-jacking it, driving it off-road, and burning it to hide the evidence.

My... testy aren't we

Perhaps you should toddle off and go ask your fellows why this question is relevant to flameworking, and this thread, since it's "outside the range of (your) knowledge". Surely someone at Carlisle knows. I would hope.

To date, I have been impressed with Carlisle torches... but if you guys don't know the answer to this very basic combustion question, and if you believe it is "largely irrelevant to... Carlisle's burners and applications"... you do give me pause.

If you are going to speak to subjects such as backfires, flashbacks, etc., and relative safety devices, it is important to understand how these safety devices work. It should not be "outside the range of (your) knowledge".

Perhaps you might add the following journals to your reading list:
Combustion and Flame
Combustion Science and Technology
Combustion Theory and Modelling
and perhaps... Combustion, Explosions and Shock Waves

Me

[ChrisCamac]

Originally Posted by bhhco

My... testy aren't we

Perhaps you should toddle off and go ask your fellows why this question is relevant to flameworking, and this thread, since it's "outside the range of (your) knowledge". Surely someone at Carlisle knows. I would hope.

To date, I have been impressed with Carlisle torches... but if you guys don't know the answer to this very basic combustion question, and if you believe it is "largely irrelevant to... Carlisle's burners and applications"... you do give me pause.

If you are going to speak to subjects such as backfires, flashbacks, etc., and relative safety devices, it is important to understand how these safety devices work. It should not be "outside the range of (your) knowledge".

Perhaps you might add the following journals to your reading list:
Combustion and Flame
Combustion Science and Technology
Combustion Theory and Modelling
and perhaps... Combustion, Explosions and Shock Waves

You must get your kicks from this sort of thing, eh?

You posted an erroneous question in a thread where it had no place. Why? Self serving reasons are all that I can imagine. Your own twisted pleasure, perhaps. Have nothing better to do maybe. Don't know, and I'm guessing that most people don't care.

I do not know the answer to your question off the top of my head, and I certainly won't waste anyone else's time here with it either.

Since you think you know so much about it, why don't you explain to everyone here why the minimum volumetric size of a propane flame (oxygen based or air based, your choice) has any relevance to flameworking as we know it? I am quite familiar with how a flashback arrestor works, and I can ensure you that your question and the answer to it have absolutely nothing to do with it.

Testy? Hardly. I just feel that a safety forum has no place for someone with your lack of respect and concern for others. If you have something valuable to add to the conversation, than get on with it already. Otherwise, stop wasting other's time, as some of us consider it valuable.

[SL Beads]

I am still very confused about the order of shutting off the system. Mike and Dale have two different ways about it. So, which should i turn off first, fuel tank or regulator? Or does it make any difference which way you follow? But, then I still don't know why I broke two regulators so quickly. I wonder if the flashback arrestor is my culprit, too. Another question with regard to shutting off the system. Is it dangerous for me to turn off the oxygen valve but leave the fuel cintinue to burn while I shut off the tank? When the fuel is completely burnt off, then I back off the T-handle. I don't remember where I learned this method of bleeding , but I have been doing this for awhile. Could this be the reason I am having regulator problems? Obviously I am technically challenged to the extreme extent. I am so hopeful that this current problems will be behind me and get back to safe beadmaking soon. Sachiko L.

[bhhco]

Originally Posted by CarlisleGuy

...You posted an erroneous question in a thread where it had no place.

???? "erroneous question" ????... That's a new one ... I've heard of erroneous answers... heck, I've read them in this thread

Originally Posted by CarlisleGuy

...Since you think you know so much about it, why don't you explain to everyone here why the minimum volumetric size of a propane flame (oxygen based or air based, your choice) has any relevance to flameworking as we know it? I am quite familiar with how a flashback arrestor works, and I can ensure you that your question and the answer to it have absolutely nothing to do with it....

That's 'assure' BTW.

I assumed from the way you framed your knowledge credentials (and my previous assumption about Carlisle's expertise -- now dashed) that you would understand the question... so, let me simplify it:

How small is flame before it just snuffs itself out (on planet earth)?

And here's the simplified answer. Not as small as you think.

Below a certain size, a flame cannot exist. That is why screens of a specific grid size inside a 'flashback arrestor' (of some specific types), can quench the flame... the backward moving flame cannot be sustained through the grid opening ... the flame snuffs out because the grid opening is smaller than the minimum flame size.

So, why is that size important to torches and flameworking... and specific types of torches? It's relative to the torch's fuel tube size... and the minimum size of the flame. It is important because some torches cannot sustain a flame inside the tube... of course, this all means nothing if a surface mix torch is manufactured faulty and are internal mixing... like buying a new car, and getting the one with bad tires.

It also is important in selecting the best flashback arrestor which provides the least impact to system performance, should a user feel more comfortable with them, versus without (assuming they might be the one who gets the car with the bad tires). Some flashback designs provide better performance for our use than others... we aren't all 'raging the torch'.

But, you have succeeded in pissing me off... something which is difficult to do so you can go research the details yourself, so that next time you post you can say more than just 'go buy tires... you need them', and be better informed... although it sounds like you feel it's a waste of your time.

And as Forest would say... that's all I have to say about that. So you can go ahead slam me with immunity . Perhaps that's where your expertise really lies. Thanks CarlisleGuy for such a edifying experience! (... oh yes... that means 'intellectual' by the way... kind of like smart).

Me

[Norskiglass]

Between Mike and Carlisle....I would say there is ample amounts of advice there to remidy the problem. I will add to this my experiance with line pressure, manifolds,etc...

Years ago I started my torch up and when I opened the outer rings *BAM* blew the hose connection right off the O2 regulator,just then I pulled my hand back off the gas knob only to produce and even higher volume of flame ~when I noticed that O2 was shooting out rapidly towards the floor.....I ran to the door,stopped and thought "My house is going to burn down".

1) I had never thought it would happen to me.

2) I bled the pressure from the lines but never backed off the regulators.

3) Whatever happened that day changed my life and the hearing in my right ear.

I now have a public studio that has a hard line system for liquid O2 and propane. The propane line is a supply line with 8-10 gauges @ each work station,for the O2 an additional two regulators are in place to do just as Carlisle has mentioned ~prevent "hunting". Over all the system has cost me approx. $11.000.00 for installation,etc.. as a result I have yet to upgrade to better eyewear for myself,~let alone a torch,however I do have what I belive to be the best system to supply the lampworking studio...and best of all it is safe!!

I had tried at first to explore the manifold system.....I side with both Mike and Carlisle on what they have said, in turn I went in a direction that leaves no complaints or problems for me, the studio, the student, or anyone else for that matter. I found it difficult to run 20-50' lines of hose for the sake of it being bulky,risky, and esp. they will have to be replaced in time due to expansion,etc.. I had problems with "hunting" and lost an O2 regulator in two weeks, and may I add it was the right one for the manifold system. I was a little mythed about running regulators on each torch....and hindsight is always 20/20.

I really belive there is plenty of great info on this thread before my two cents and I believe the school should looking into a new system. ( I sleep better @ night)

[ChrisCamac]

On second thought, I am removing my response to bhhco. Just not worth it.

[ChrisCamac]

Originally Posted by SL Beads

I am still very confused about the order of shutting off the system. Mike and Dale have two different ways about it. So, which should i turn off first, fuel tank or regulator? Or does it make any difference which way you follow? But, then I still don't know why I broke two regulators so quickly. I wonder if the flashback arrestor is my culprit, too. Another question with regard to shutting off the system. Is it dangerous for me to turn off the oxygen valve but leave the fuel cintinue to burn while I shut off the tank? When the fuel is completely burnt off, then I back off the T-handle. I don't remember where I learned this method of bleeding , but I have been doing this for awhile. Could this be the reason I am having regulator problems? Obviously I am technically challenged to the extreme extent. I am so hopeful that this current problems will be behind me and get back to safe beadmaking soon. Sachiko L.

By turning off the tank first, then bleeding the lines, you are releasing the pressure off of everything except the tank itself. Then the last thing you do is turn out the T handle to relax the regulators diaphragm.

If you turn out the T handle first, and then turn off the tank, you are actually trapping a pressure build up in the inlet leg of the regulator (the part that screws onto the tank itself.

So my recommendation is this:

1. turn off the supply tank.

2. bleed out the lines from your torch.

3. turn out the T handle from the regualtor.

Hope that helps.

[MikeAurelius]

Lynne - if up until now you have been using surface mix torches, and are now adding a pre-mix (the Smith is a pre-mix), you should add a flashback arrestor on the propane line on that particular torch.

Originally Posted by Islandgirl

While we're on this subject... I have the old style regulator on my propane tank... no dials at all. Instructions when I got it in '94 JIm Kervin's original spiral bound book) were to set it and leave it... and that's just what I've done... I might add since it has no dials that it is a real pain to set. On the other hand it's held the pressure through many moves and hours of usage... Comments???

Also I'm buying a Smith 'little torch' for jewellery I don't have flashback arrestors on my lines now, I'm hoping to run it off my concentrator and aforementioned propane... I'm thinking I should put an arrestor on my propane if I'm going to add this torch into my 'harness'... RIGHT??? I've had jewellery torches flash back into the handle a couple of times, do they need the arrestor on the line?

Lynne