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Archive 1

Blowtorch / blowlamp

The term “blowtorch” is apparently subject to some regional variation. The illustrated paraffin blowtorch, and its modern propane derivatives are known as "blowtorches" in the UK. Significantly they are fuel / ambient air combustion devices, and do not use oxygen or pressurised air to enhance the flame. They are usually used for soldering, and limited silver soldering or brazing only. In the UK, welding torches are known as welding torches, gas torches, or oxy-acetylene torches.

Propane/compressed air torches are suitable for general brazing, and are usually known in the UK as brazing torches.

Cutting / welding

For oxy-acetylene cutting, a variant torch is usually used, which has a second oxygen regulator, hose and stop valve on the torch, and a hand operated oxygen valve on the hand grip of the torch. An additional oxygen jet is located coaxially in the centre of a nozzle that is otherwise similar to a large welding nozzle. Operating the hand valve applies a much higher pressure of oxygen (if my memory serves me, around 40 to 50 psi on the oxygen and DO NOT exceed 15 psi on the acetylene) to the jet in the centre of the cutting nozzle. Initially the oxygen blast is left off and the torch's normal flame is applied to the work to be cut, until the area under the torch attains a cherry red heat. Applying the oxygen jet to the cherry red target area ignites the metal directly under the oxygen jet. The reaction is sufficiently fierce that at this point the heat input from the gas torch is irrelevant, and the blast jet can be advanced through the workpiece at considerable speed, with the cut advancing by a combination of the workpiece being consumed by the blast jet, and/or melted and displaced by the blast jet.

If the oxygen blast is switched off, the combustion reaction then ceases very abruptly, such that it is possible to stop the cut quite accurately. Restarting the cut will require that the torch is played at the same spot until the area regains a cherry red heat, before the cut can be restarted.

The article gives the impression that a welding set can be used for cutting. This is not normally the case, a cutting torch is unwieldy and suitable for only very heavy duty welding, and a standard welding torch does not have provision for a cutting blast. 00:01, 1 June 2005 User:212.159.71.40

  • EDITORS: There is some overlap between the gas welding, oxy-fuel welding and the oxyacetylene page. The oxyacetylene page had its own set of instructions for lighting torches. I added a lot of safety material to this page. I feel like this stuff should

probably be merged in some way. 16:31, 22 June 2005 User:Lobstericus

I was reading up on cutting, when I saw the procedure for shutting down the torch. It states that you should shut off oxygen first, then acytelene. Which is wrong. One of the first things they taught me, was to shut off the acytelene first, so that the oxygen will blow out any residual gas still inside the torch.

Agreed - Shutting off the Acetylene last can cause a flashback (>20 years experience) Patris Magnus 23:19, 25 August 2006 (UTC)
This seems to have a lot of different opinions (about the shut down procedure for oxy/acetylene). I think that this how-to section of the article should be deleted, because the wikipedia page on "guidelines" states that there shouldn't be "how-to's".
In that way, a big chunk of the O/A article will be removed, but if people want to know how to weld, they can do just what the article says- go to a technical collage or other school that teaches welding. Or, there could be a few names of books or something. There probably should be a section on safety, though.

Shut off oxygen first or acetylene first?

The section "Shutting down" has stayed for a long time as:-

To shut down the torch, close the acetylene torch valve first, then the oxygen. (A 'pop' may occur if you reverse the order. The pop throws carbon soot back into the torch, which may partially plug the gas passages.)

Next, close both the tank valves. Turn on the torch valves again, one at a time (acetylene first), to bleed any remaining pressure, then close them again. Lastly, turn the regulator valves until there is no pressure on the adjusting spring and the screw turns freely.

But at 03:47 on 12 November 2006) the anonymous user User:65.102.119.136 changed it to:-

To shut down the torch, close the oxygen torch valve first, then the acetylene valve. (This is so that you can detect leaks, and for other reasons.) If you hear popping, the oxygen valve dosen't seat. If the flame stays, the acetylene or gas valve dosen't seat.

Next, close both the tank valves. Turn on the torch valves again, one at a time (acetylene first), to bleed any remaining pressure in the hoses, then close the torch valves again. Lastly, turn the regulator valves counterclockwise until there is no resistance on the adjusting screw, and it turns freely.

Coil up lead and torch neatly and carefully onto cart, and put away cart.

Which is correct? Or should we be NPOV and say that there are contrary opinions about which gas to switch off first?

As a qualified gas welder, I can assure readers of the correct sequence. When lighting up the torch, open the acetylene first, light it with a spark striker and then introduce the oxygen. The reason for this is to ensure that the mixture is ALWAYS acetylene-rich when in safety mode (ie, when not actually welding). When shutting off, the oxygen should be shut off first, followed by the acetylene - again ensuring that the mixture is acetylene-rich as it is closed down. Remember that an explosive situation is one in which there is sufficient oxygen available to ensure the spontaneous combustion of the mixture. An acetylene-rich mixture is much less likely to explode than and oxygen-rich mixture. Moreover, it is not ever a good idea to 'purge' acetylene with oxygen - indeed, that would be dangerous. Remember, in the absense of oxygen, acetylene can not burn at all, but pure oxygen can cause a huge number of materials to spontaneously combust, ignite, explode. Best wishes, Nick Nakorn MTIT.mech B.Sc. hons, Devon, UK —Preceding unsigned comment added by 91.84.102.0 (talk) 07:05, 23 November 2008 (UTC)

  • I can find no reference to a gas leak procedure such as this. I do know that using a flame to detect gas leaks is not the best way to do it. I do however have many Navy references indicating that the acetylene valve should be shut off first and then the oxygen to avoid residual flammable gas in the torch flashing back. The pressure wave created in the pop (small explosion) can damage torch internals. In addition, we have had this conversation before and I thought it was resolved. It must be in the archive somewhere. Patris Magnus 17:59, 13 November 2006 (UTC)
  • I think that the idea of a npov would be good, because there seems to be quite a lot of controversy here. Both opinions have good reasons to back their opinions up, and some think that it should be just taken off the article. All reasons make good sense, so a npov is just a good idea. It probably dosen't even matter that much beacuse not that many people are looking up "oxy-acetylene", but still, at least some people care enough to discuss it.

The old Oxy-Acetylene Handbook by Union Carbide, 1975, p 87 confirms turn off acetylene first then the oxygen valve. This should not be NPOV. ArcTech 04:22, 1 September 2007 (UTC)

Acetylene is ALWAYS turned off first so that the oxygen can blow out the remaining acetylene and flame preventing flashback. ~~138 —Preceding unsigned comment added by 65.246.232.101 (talk) 15:15, 13 March 2008 (UTC)

Instructional content

The how-to needs to be taken out of the article. It was just merged in, but it doesn't belong in wikipedia in the first place. Unless we're writing a wikibooks how-to, we shouldn't write a how-to. Night Gyr 23:07, 17 February 2006 (UTC)

  • I put the section back. It is relevant information. If we remove all matter that is instructions how to operate anything, Wikipedia will lose gigabytes of text. Anthony Appleyard 07:40, 18 February 2006 (UTC)
    • And be much cleaner to read. Check out WP:NOT. Night Gyr 11:03, 18 February 2006 (UTC)
      • Sometimes it is like unscrambling an egg, trying to separate "information about X" from "how to operate X". Anthony Appleyard 16:47, 18 February 2006 (UTC)
        • It's not hard at all. Just take out anything that reads like an instruction (you should do X, next do X, don't do X) and if we lose encyclopedic information in the process, rewrite it as facts. The second-person voice and the word "you" should not appear anywhere in encyclopedia articles (unless it's a quote), nor should normative statements like "should." I'm going to move the Howto to the talk page, since it's explicitly contradictory to WP:NOT and doesn't add anything encyclopedic to the article. Night Gyr 21:04, 18 February 2006 (UTC)
  • I did not type in this how-to information. It was in Wikipedia before, in Oxy-fuel welding and cutting or in Oxyacetylene, and people left it in. There is people's safety at issue: if I do not leave in the safety warnings and safety advice, people may think that using an oxy-gas torch is easy and merely point-and-shoot like firing an AK47. Many people read Wikipedia for practical information, and if safety warnings are not put into the pages about a particular topic, some people may therefore decide that those hazards do not exist. As far as I am concerned, safety warnings and safety advice ARE encyclopedic, because someone's life or limb may depend on them, since in many countries a member of the public can easily hire or buy an oxy-gas torch to do a bit of cutting or welding. More important than much of the reams of matter allowed to stay in Wikipedia about the doings of obscure science-fiction characters. I admit that there are limits: for example, falconry training is too complicated to describe adequately in Wikipedia. But here the necessary safety advice about procedure can be described quickly. Anthony Appleyard 22:35, 18 February 2006 (UTC)
  • Please try work it out on this talk page before reverting each other any more. In my opinion, the instructions on how to weld and operate the equipment safely are inappropriate. However, some content can be saved if it can be rewritten to describe the process of welding and the safety measures employed, as suggested by Night Gyr. Also, the reasons given above state the need for safety information to be available, but that need does not make the information encyclopedic. While Wikipedia is more expansive than any others, it is still an encyclopedia, which is not used to distribute safety information. This does not mean that dangers should not be discussed, they should be in an encyclopedic manner, but the purpose of the text is not to prevent people from hurting themselves. -- Kjkolb 01:03, 19 February 2006 (UTC)
  • As Night Gyr asked, please continue this discussion on Wikipedia:Mediation_Cabal/Cases/2006-02-19_Instructional_information_in_Oxy-fuel_welding_and_cutting. Anthony Appleyard 06:33, 19 February 2006 (UTC)

Sorry about the bold letters and instructional tone - I've never commented on Wiki before so did not know any of the rules. But I am amazed at the number of '0fficial' sources (such as instructional videos and university websites) that get the order of things wrong. If all equipment is in good order, including flashback arrestors, then the question is largely academic, but it is also true that oxy-acetylene explosions kill and injure people. Surely it is vital that instructional copy is either banned completely or explained very fully. I also now know that sources should be quoted. The UK Health and Safety Executive used to be fully in favour of oxygen off first but now simply says it is a usual practice. The change in the position might be due to the comparitively recent widespread adoption of flash-back arrestors and the greater popularity of other forms of welding. Nevertheless, my 'shout' in this discussion page is I think enough to explain why there is a safety issue - it also seems odd not to want to prevent accidents. Best wishes, Nick —Preceding unsigned comment added by 82.152.251.53 (talk) 14:28, 23 November 2008 (UTC)

RfM

I've put in an informal request for mediation at Wikipedia:Mediation Cabal/Cases/2006-02-19 Instructional information in Oxy-fuel welding and cutting. Hopefully that'll get some more eyes on this page. Night Gyr 00:20, 19 February 2006 (UTC)

Mediation

This is an informal mediation attempt in reaction to Wikipedia:Mediation_Cabal/Cases/2006-02-19_Instructional_information_in_Oxy-fuel_welding_and_cutting.

If you want some more eyes maybe you should have made an WP:RfC or asked for a third opinion. I can provide a third opinion if you ask for it, of course, but as mediator I aim to be impartial unless explicitly asked for an opinion. --Fasten 11:18, 1 March 2006 (UTC)
I didn't even know WP:3O existed. Then again, apparently no one else does either, since there's no backlog. I think a third opinion would be good; this isn't a very busy article so there aren't many editors around to workout a consensus on it. RFC didn't seem appropriate because that requires trying and failing to resolve a dispute first and I was under the impression that it was mainly reserved for egregious cases. Night Gyr 14:25, 1 March 2006 (UTC)
RFC requires trying and failing to resolve a dispute first? What make you think so? I'm not aware of this. --Fasten 15:41, 1 March 2006 (UTC)

I might be confused, but I was looking at "Any RfC not accompanied by evidence showing that two users tried and failed to resolve the same dispute may be deleted after 48 hours." I could be wrong, though. Night Gyr 17:16, 1 March 2006 (UTC)

This is for disputes over user conduct and does not apply to content disputes. --Fasten 17:27, 1 March 2006 (UTC)

I'm closing this case. --Fasten 12:54, 20 March 2006 (UTC)

More historical information

A link to a free e-book.

I've no idea how old it is, but the text has a "feel" to it that appears to date it to the early 20th century. There's no metric units mentioned and the terms 'Sulphuretted Hydrogen' instead of hydrogen sulphide and 'Phosphoretted Hydrogen' instead of phosphine are definately old terminology. Unfortunatly it's just the text, none of the illustrations are included.

Instructional matter?

Concerning a current controversy about instructional matter in page Oxy-fuel_welding_and_cutting, see this link.

Move to Wikibooks?

Glass?

I often used similar tools for melting glass. Of course, acetylene flame is too hot and will melt away the glass to nothing, but using methane with oxygen ensures the right temperature for making Pyrex glass workable. Ossoduro 09:34, 10 August 2006 (UTC) Oxyhydrogen flame ?Mion 16:23, 10 August 2006 (UTC)

Removed "do not fully empty an acetylene cylinder"

Hi, I just deleted the "do not fully empty an acetylene cylinder" hint in this article, as that recommendation is unsubstantiated by any current or older literature I can find about the use of cylinderized acetylene. I made an exhaustive search of welding-safety web sites, PDF-format safety documents, etc. produced by suppliers, government agencies, and educators, and found scant or no reference to this rule.

If you believe this hint / rule should be included in the article, please substantiate it with at least a couple of up-to-date footnotes that conclusively establish its importance.

Anachron 18:30, 11 August 2006 (UTC)

  • At my company we use an acetylene tank for purposes other than welding, but we are told never to let the cylinder pressure go below 75 PSI (we usually recieve them at 250 PSI). There are also other somewhat odd precautionary rules we are asked to follow. For example, we are not supposed to lay the cylinders on their sides or upside down. The reason for these rules may be due to the fact that acetylene is usually dissolved in acetone (not sure why). It may be that below some pressure the amount of acetone in the gas may be too high (though i don't know why this would be a problem). As for putting them upside down or on their sides, it's obvious that if there is a liquid in the cylinder that allowing the liquid level to go above the exit valve could be problematic. Thesunisshining 00:26 PST, 6 January 2006

Welding gas distributors will charge a cylinder clean up fee if you run the acetylene completely out. I believe it is because the acetone starts to come out of the valve similar to turning the cylinder on its side. ArcTech 04:26, 1 September 2007 (UTC)

Yes, anywhere below 75 psi and you'll get more and more acetone out of the tank, eventually leading to the clean up fee most likely because it'll begin to expel acetone and that has to be replaced... this article should probably be replaced with an advisory notice that the procedure is not required, yet users should be warned that most re-fillers will charge for the acetone to be replaced... —Preceding unsigned comment added by 74.87.82.86 (talk) 01:31, 5 February 2008 (UTC)

Moving to wikibooks...

Erm, could you folks please stop the edit war for a minute, and let me know which version is supposed to be transwikied for a wikibooks how-to? I'm an admin on wikibooks, and will happily move the page, but it would make sense to move the version with the how-to stuff. --SB_Johnny | talk 12:17, 4 September 2006 (UTC)

NPOV violation

  • This article contains the highly POV statement:-
"A cutting torch is used to cut a steel pipe. Note that the worker is not wearing full-face protection, which is poor safety procedure."
This statement is a blatant disregard for this facility's strict NPOV policy and I demand the problem be recitifed immediately. Damien Shiest 00:30, 18 December 2006 (UTC)

Would like to note that the adjustment to this area of the article still implies that a full mask, and gloves are "standard safety procedure" is completely false, and was most likely made by a person who has never used an oxy-acetylene torch for welding, cutting or otherwise. even in high school, they won't make you wear anything besides the green eye shields with a flip-up visor, mostly because the heavy gloves used for SMAW or stick welding are extremely heavy and fatigue your hands quite quickly, also, face burns are not an issue, as sparks rarely make it past your elbow area. if someone wants to wear gloves and a face mask, sure, go ahead, but its pointless. absolutely nobody that I know who uses Oxy-Acetylene welding, cutting, brazing, ect. would not even consider wearing gloves and a full face mask on a regular basis. safety is all and good, but you have to consider how much it applies to the situation... this issue also seems to bleed over to using heavy gloves when working on a bench grinder. there are far more advantages to not using the safety feature and there is hardly any risk to not. just use common sense. —Preceding unsigned comment added by 74.87.82.86 (talk) 01:40, 5 February 2008 (UTC)

Torch pressures?

Which of these is right?

  • For cutting, use 40 psi for the oxygen and 5 psi for the acetylene. NOTE: DO NOT SET THE ACETYLENE REGULATOR VALVE HIGHER THAN 15 PSI (103 kPa)!: if you do, the acetylene can explosively decompose into carbon and hydrogen gas all by itself.
  • For cutting, use 15 psi for the oxygen and 2 psi for the acetylene. NOTE: DO NOT SET THE ACETYLENE REGULATOR VALVE HIGHER THAN 15 PSI (103 kPa)!: if you do, the acetylene can explosively decompose into carbon and hydrogen gas all by itself.

Anthony Appleyard 07:56, 16 February 2007 (UTC)

Depends on what you want to cut. Like, if you wanted to cut 1/4" hot roll steel you'd use 20/5 (O2 psi/Fuel psi). 17:12 & 17:16, User:Maineman1987

Plagiarism http://www.answers.com/topic/oxy-fuel-welding-and-cutting

I most often cut 3/8" plate at 25psi oxygen and 7-8 psi acetylene. But your pressures are dictated by your base metal thickness and your cutting tip size. You wouldn't cut 1" plate with a size 000 tip set to 15/10 psi. Any welder reading this would know this is ridiculous. Get a cutting chart from any welding supplier. —Preceding unsigned comment added by 65.246.232.101 (talk) 15:29, 13 March 2008 (UTC)

Tourch pressures

The pressure to the torch is variable depending on the size of head used. There are multiple different cutting heads and welding heads, each appropriate for certain thicknesses. Also the picture with the comment “A cutting torch is used to cut a steel pipe. Note that the worker is not wearing full-face protection or gloves, which is poor safety procedure.” Full face protection is not required, the welding greens that he is wearing is fine. Gloves can be a bad thing to be warring wile operating a torch, if the torch is leaking gas could fill the glove, and anyone can imagine what would happen if a spark set that off. —The preceding unsigned comment was added by 72.39.250.218 (talk) 17:39, 10 March 2007 (UTC).

You want to be wearing gloves! You should be checking your equipment so things like that don't happen. 17:12 & 17:16, User:Maineman1987

please read the above comment (about two or three sections up) on gloves and a full facemask. you shouldn't be wearing gloves. the flame is directed opposite you at all time and there arent many splash sparks that make it anywhere near your face. gloves just heat and fatigue your hands, a waste at best. i'd guess you've never used an oxy-acetylene system before, the only reason you'd need gloves would be if you were using a massive flame to remove sections of girder or something like that, or if you were a dummy who insisted on picking up your metal before quenching it (e.g. you don't own tongs to pick it up with) —Preceding unsigned comment added by 74.87.82.86 (talk) 01:46, 5 February 2008 (UTC)

Torches: Injector Torch

The article links to external diagrams to show the difference between "Equal Pressure" and "Injector" torches, but the two diagrams linked to are the same file. —The preceding unsigned comment was added by 60.241.10.57 (talk) 00:02, 16 May 2007 (UTC).

Cleanup

  • Seeing how my cleanup of this article was reverted by Anthony Appleyard, (which, by the way was the first time anyone who was not a vandal has ever reverted one of my edits in my 2+ years of editing), I was wondering: Is it REALLY necessary for their to be step-by-step detailed instructions on the operation and use of the equipment. I was under the impression that this was an encyclopedia, not an instruction manual. What I cleaned-up was a long, poorly written, and extensively copied article that had sections taken out and replaced with links to a 'website' that doesn't have a name. Anthony Appleyard has said that this article has been like this for at least a year, yet i find it hard to believe that a poorly written article such as this has been in this state for so long. Also, there has been a cleanup tag since December 2006. So excuse me if I was trying to do a major reorganization of this article, but it needs help. That said, what should be left in and taken out? What does everyone else think? Caster23 23:44, 23 July 2007 (UTC)
  • Hereinafter:
    • Version A is [1], the latest form of the long-standing version with al the instruction matter in.
    • Version B is [2], User:Caster23's new shortened version.
    If B's purpose is to remove all "how to" type matter, that has not ben achieved: B still contains instruction-type matter.
    • "that had sections taken out and replaced with links to a 'website' that doesn't have a name."
      The web page pointed to DOES have a title at its top. Because of Wikipedia rules about copyright, I replaced copyvio matter by links to the external page that it was a copyvio of.
    • "Is it REALLY necessary for their to be step-by-step detailed instructions on the operation and use of the equipment"
      People often read encyclopedias for practical information, which includes how to do things, or links to information about how to do things. If all this information can be found adequately detailed in external sites, then replace this on-line matter by pointers to those external sites, or to a good printed book which is still in print and is likely to remain in print. Until then, if it reasonably covers the subject and is not too bulky, it could stay here?
    • "poorly written"
      Please list specific faults.
    • Note: I have just histmerged an old cut-and-paste move from Gas welding (at 05:06 on 6 February 2005 by User:David Gale.)
    • User:63.67.241.184 started this page was started as Gas welding at 01:25, 20 February 2004, and has gradually developed since. At date it has 451 edits. About its biggest single accretion was two merges (from Cutting torch and Oxyacetylene which I did on 17 February 2006: [3]).

Anthony Appleyard 05:16, 24 July 2007 (UTC)


Thank you for your reply. A few comments

  • If B's purpose is to remove all "how to" type matter, that has not ben achieved

Where? I removed the sections entitled 'setting up the equipment', 'shutting down', and 'learning to operate...'. I also cleaned-up the intro. Please see WP:NOT#GUIDE. Ive only followed the rules.

  • "poorly written" Please list specific faults.

Well for starters, having links that look like this http://64.78.42.182/sweethaven/BldgConst/Welding/lessonmain.asp?lesNum=4&modNum=1 in the middle of a section is a poor job. Also, references that appear in the middle of the article and (if having the detailed instructions in as per the current revision) sentences that are one lined {e.x.

Make sure that the regulator valves are turned all the way out and that all the valves on the torch are closed.

Screw out the knobs on the regulators until loose (0 setting).

Make sure the valves are easily accessible in case emergency shutdown is necessary. )

only make the page longer and contribute to it looking bad.

  • Finally, I would like to say that I will be making extensive changes to the article in short time and will use the policies located here: WP:NOT WP:LOP WP:SIMPLE.

Caster23 06:01, 24 July 2007 (UTC)

    • For my first edit to this article, I moved the sections 'regulator', 'gas hoses', non-return valve' and 'check valve' to there new place under the apparatus section because they are mentioned there and it only seems logical to make them sub-sections rather than having there own section. I also expended and gave a source to the 'gas hoses' section (which had nothing but a link) and also made minor edits to other parts of section 'Apparatus'. Caster23 16:04, 24 July 2007 (UTC)
    • I have now cleaned up the safety section that was full of common sense instructions and tips. Also, the section entitled 'Setting up the equipment' and 'shutting down' have been removed because, as I have said before, wikipedia isn't an instruction manual. Please see WP:NOT#GUIDE. Perhaps some of the removed material deserves a place in this article but most of it seems to have been taken from an unknown source and more time would be needed to go through and take bits and pieces and re-write and re-include it in other sections. Caster23 17:04, 24 July 2007 (UTC)

Petrol-Torch

Hi Folks,

I think we should delete the reference to the Gasoline or Petrol-Torch. It is a proprietary product and it is dangerous or deadly in the hands of the untrained user.

The reference leads one to a DOE study at one of their decommisioned nuke plants in Fernal, OH. This is basically a vendors attempt to sell the government on new technology. The Petrol-Torch is a proprietary product of Petrogen. The study tells us there are 120 torches in use around the world. 100 of them are used in Russia.

Gasoline and a flame that can melt steel are dangerous or deadly to the common welder. This techonology is very exotic and I can't recommend its inclusion in Wikipedia.

What say ye?

ArcTech 02:09, 9 September 2007 (UTC)

  • Leave it in. Include a warning that petrol torches are dangerous. Anthony Appleyard 05:37, 9 September 2007 (UTC)
  • Please explain why proprietary torches are in? I'm new here and I would like to know the rationale. These torches are not discussed in common welding literature such as Sachs or Bonhart. I don't find them discussed by Praxair, Air-Liquid, or US Welding. I haven't checked AWS recommended practices yet.

ArcTech 01:20, 11 September 2007 (UTC)

Homemade Torch?

Can't find any links for building a homemade torch. —Preceding unsigned comment added by 69.152.168.49 (talk) 19:49, 21 April 2008 (UTC)

Unstable above 207 but Ok at 1700 kPa?

This method is necessary because above 207 kPa (30 lbf/in²) (absolute pressure) acetylene is unstable and may explode.[clarification needed] There is about 1700 kPa (250 lbf/in²) pressure in the tank when full.

I added a clarifyme tag in the Acetylene section because the stated reason for the packing method seems incomplete. If acetylene is unstable above 207, then why is it not still unstable at 1700 kPa? Is there a way to explain this better? The Agamassan article implies that a porous substance must be used that never forms any cavities that would allow the free gas to form. So, is it that the porous material has pores small enough to make explosion chemically unlikely? -84user (talk) 00:09, 16 August 2008 (UTC)

Free acetylene is unstable above 30psia and may explosively decompose. Acetylene in the tank is dissolved in acetone and the acetone/acetylene mixture is physically stabilized by being packed in with absorbent material such as kapok, diatomaceous earth, etc. As with many chemical mixtures, the chemical properties of the constituent parts are altered by the nature of the mixture. In this case the sensitivity of the acetylene is reduced by its being mixed with acetone. Patris Magnus (talk) 13:30, 23 September 2008 (UTC)
Archive 1
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