Hey, there's the info I've always wanted. I had wondered what the reaction might be when no oxygen was present, and now I understand. Now, what is the REAL pressure level that acetylene will explode at? Or is it temperature dependent? The regulator gauge is redlned at
15 psi, but there is 150 psi gas upstream of the regulator before there's any liquid. It it something to do with pressure/temperature/impact risks to the hoses?
15 PSI is where acetylene *CAN* start to break down. Not where acetylene
*WILL FOR SURE* start to break down...
I've often wondered the same as you - "If 15 pounds is the "magic" number, why is it OK to have 10 times that between the "raw tank" side, and the "regulated hose" side?"
My theory is that it's partly the pressure, partly the quantity, and partly the lack of any significant "stimulation" - Above 15 pounds isn't neccesarily "kaboom" unless there's enough acetylene available to make it happen, and some external energy source (pressure, shock, heat) to trigger it.
Supposedly, it has something to do with the free volume at the 150 PSI. In other words, a whole tank of Acetylene at 150 PSI is a bomb, but a properly packed and acetone-saturated tank with just a little free volume right at the top is not. Don't ask me for the physics behind this, I don't know it.
All it takes is a drop or two of water in a pipe and no matter how much heat is apllied you usually windup badly oxidizing the pipe / fitting flux and just botching the entire job. Bread works great though! Visit my website:
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expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy.
This happened to my cousin and her huaband several years ago in the Dallas area. He'd borrowed an O-A rig from work to do some quick repairs at home. This was OK'ed by his boss. He was a manager, not a welder, but could weld. After he finished, he put both tanks in the trunk of his car, in their closed, attached garage. The water heater was also in the garage. Evidently the acetylene tank was leaking, or he hadn't gotten it shut-off completely. During the night they were violently awakened by the explosion. Fortunately, their bedrooms were on the opposite end of the house, and they got out. Part of the car was found across the street in their neighbors front yard. The roof had cedar shake shingles and went up like dry kindling. They got out, but there home, cars, and belongings were gone. Because he was relatively high in the company, they went after the tank supplier. In the end my cousin's husband got everything replaced that was replaceable.
Sometimes in a workplace you find snot on the wall of the toilet cubicles. You feel "What sort of twisted child would do this?"....the internet seems full of them. It's very sad
"Jon Elson" wrote: (clip) In other words, a whole tank of Acetylene at 150 PSI is a bomb, but a properly packed and acetone-saturated tank with just a little free volume right at the top is not. (clip) ^^^^^^^^^^^ Earlier on, someone gave a website regarding the safety of pressure cylinders, which contained the warning that DENTED acetylene cylinders are dangerous, because there can be a separation of the packing from the sidewall, so a potentially explosive small volume of undissolved acetylene can collect. This has been floating around in the hollows of my skull ever since. How can it be dangerous to have a little sliver of acetyleye gas along the sidewall of the tank, but totally safe to have acetylene at the same pressure on the high side of the regulator?
Maybe someone who is an expert on this can clarify.
On Tue, 25 May 2004 06:57:20 -0500, Jim Kovar vaguely proposed a theory ......and in reply I say!: remove ns from my header address to reply via email
DUUUUH! This is Govmint polisy man! Who cares?
The reply will probably be "dollars".
Seriously, the farmers have asked the same question. At present Amm Nitrate is till _sort_ of legal, with lots of talk of treating it as an explosive; licenses, storage etc. Trouble is, one company voluntarily withdrew its Amm Nitrate and farmers were asked to return their stocks. So we have a looming election and a company that stands to sell costlier fertilisers!
I do have to say that I was looking at possible ways to make a bomb using other means of getting O2 spread amongst fuel, with the idea of complaining about this daft idea. NH4NO3 (like other solid oxidisers) has a frightening amount of oxygen tied up in it per weight! I am not sure how much of this is available for conflagration, but even 1/4 of it is pretty scary.
Sometimes in a workplace you find snot on the wall of the toilet cubicles. You feel "What sort of twisted child would do this?"....the internet seems full of them. It's very sad
The one poster that posited, "more power" was correct.
If water is in the pipe it won't get above 212 deg F...... unless it is a closed system, in which case you will have superheated steam at, well, we'll use a 700 degree figure at about 3200 PSI.
The only way you are going to solder in a pipe with water in it is to boil the water out.... if you get the temperature of the pipe much above 800 degrees and water gets *back* to that point it will immediately flash into steam.... with literally explosive results. Try google and you can find some truly terrific boiler explosions...... hurling large parts for long distances...... and worse.
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