Acetylene generators - how dangerous?

Hi folks
I've seen a few pro shops which still have one of these, and brand new
even. After reading the horror stories in Usenet posts, I wonder if these
devices have safety plugs the way acetylene tanks do, so that
overpressures can be vented? What is the bottom line here? I would be
using one for my home shop, since I'm finding the cost of the monthly
acetylene refill quite high. I do both brazing and welding. I'm not sure
about an arc welder since it causes noticeable rippling in the house
lighting and the appliances, and PCs are a concern (all them are hooked to
line regulators)
Any advice thanked in advance
regards,
Mongke
Reply to
mongke
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for home use?? with one user???? (previous remarks are supposed to sound incredulous) seriously, have you considered just getting a larger bottle? acetelyne generators (unless they make smaller ones i've not seen) are used for major industrial many, multi, full-time users
Reply to
dogalone
An inverter tig/DCstick welder might be the answer for you.
Reply to
Pipper
all kidding aside (i remember going through welding school, which had 'em) and thinking i had to get one of those, along with a liquid O² tank: my puny B tank was causing the same issues you describe....
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the regulations/hastles/space requirements/etc. would be prohibitive
Reply to
dogalone
hey, now: (found on eBay):
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Reply to
dogalone
Well just yesterday I happend upon a body work shop with one of these. A small thing, some 70 centimeters tall and 50 centimeters diameter. I've seen larger, about 5 feet tall.
mongke
Reply to
mongke
Way outside my budget by now :(
Reply to
mongke
this i would have to see: the precipitater alone would have to be at least that size (sounds like you're describing the headlight off of an old car)
Reply to
dogalone
just in case, 50 cm are 1 1/4 ft aprox; 70 cm are 2 1/4 ft approx I was raised in metric, sorry :)
if I can find the shop again (I was looking for an address and passed it on the run) I might take a picture.
mongke
Reply to
mongke
I've never seen or heard of modern day, compact acy. generaters so I would be interested in who is making them and what they cost, just for curiosity sake. What part of the world are you in? I would also like to be present when you tell your homeowner insurance agent that you keep an acytelene generator in your garage ! Have you checked the price on upgrading your acy. bottle to one of the big ones? And the better price you get on refills? That might be the way to go. The larger the bottle, the cheaper the gas.
JTMcC.
Reply to
JTMcC
Umm, I think the insurance agent is going to say, "it's a tank of WHAT? Now just exacty HOW large is the tank? And what's that stuff inside of it for, exactly?"
Acetylene generator or compressed gas tank, I think both are going to induce heart palpitations in any agent.
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Reply to
jim rozen
Your standard ins. agent doesn't care how large of a cylinder you keep in the garage, it is a well documented, and tested and certified method of containing a dangerous gas. Now, say you want to manufacure the same dangerous gas, with a groovy device, in the garage, then your liability goes way way up. Ask if you don't believe me.
JTMcC, who has way more knowledge and experience with insurance policies and agents than he really ever wanted or needed.
Reply to
JTMcC
"A DANGEROUS GAS???? You're keeping a DANGEROUS GAS on your property!? Cancelled!"
Jim (guessing how the phone call would go)
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Reply to
jim rozen
Guess would be the key word here, most houses are plumbed for delivery of a "dangerous" gas. Your comments have no relation to actual insurance company expectations and or policies IMO. I was attempting to stick to the real world ins. co. rules and reg's. Your comments swerve so far out of the real world that they border on hysteria or hyper flatulance in pursuit of a goal you can't justify with facts or experience.
JTMcC, who is pretty used to dealing with insurance companies concerning compressed gasses, and pressure vessels.
Reply to
JTMcC
You must not live in NY state then John. Right now insurance companies are *so* desperate for money that they will cancel auto or homeowners policies for almost any reason at all. A co-worker had some trees come down on his property during a recent ice storm. He had them removed, and put in his FIRST claim on his policy, which he's had for 30 years. They paid the $1K claim and then cancelled him. His new policy costs much more than the one he had.
This is not hysteria, just simply the facts that in NY insurance companies lost a bundle after 9/11 - or they would have you believe that's why they're scrabbling for increased rates, any way they can.
I was recently rear-ended, had minor damage to the bumper on my truck. The other company contacted me to get an estimate, I said, no thanks, I'll get another bumper and put it on myself. No claims, nowhere, nohow.
I'm not sure what kind of goal you think I'm after here, but the facts and experience are *all* there. This ain't just methane gas and smoke.
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Reply to
jim rozen
Hmmm.. *puts on chemistry hat*
Lesse, 1mol of gas is 1 (avagadro's number) of molecules in... uh... cubic meter? hmm.. I'll just grab some numbers... Given STP, air is.. 29g/mol and 1.2kg/m^3. Propylene is (by memory) C3H6, so it is 3*12+6*1 = 36+6 = 42g/mol. So 1 cubic meter will weigh 1.2*42/29 = 1.75kg/m^3, or uh.. 1.75 * 2.2(lbs/kg) / 35.3(ft^3/m^3) = .11 pounds per cubic foot. So 5lbs. is about 46 cubic feet?
Tim
-- "That's for the courts to decide." - Homer Simpson Website @
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Reply to
Tim Williams
There would be a premium? How much? Or they simply would refuse to insure?
Mongke
Reply to
mongke
For gasses, the molar volume is 22.414 L at STP.
hmm.. I'll just grab some numbers...
Nope, seems impossibly low. I've been using this same 5 Lb tank for at least 5 YEARS, without using it up. I've used up something like 200 Cu. Ft. of Oxygen so far. I don't know what fuel/Oxygen ratio is used for it, but it still seems like there's got to be WAY more than 46 Cu. Ft. of gas in a 5 Lb tank of liquid.
So, 42 g/mol, and 5 Lbs is 2.27 Kg or 2272 g. So, 2272 gm is 54 mol. And, at STP the gas would occupy 54 * 22.414 L = 1210 L. Ahh, 42 Cu Ft. Back in a circle. But, it can't be right. Well, consulting the data at
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they say the specific vol is 9.4 Cu Ft/Lb, so with that I get 47 Cu Ft for 5 Lbs. Humpf!
Well, either that tank is really a 25 Lb tank, and I'm badly misremembering, or the mixture is such that the fuel gas flow is vastly less than the Oxygen flow.
ANYWAY, after all that blather, I have found it to work quite well for brazing, at least. It certainly gets hot enough to weld with, as I have accidently burned steel when I got carried away when brazing. It would start spitting sparks like from a grinding wheel.
Jon
Reply to
Jon Elson
Really ? Got any pictures. I'm surprised that they still have one and _amazed_ that any remained in service much beyond WW2. The running costs must be steep.
They're much safer - often to the level of being process-inherently safe. A simple way is to make their gas receiver a water-sealed floating gas-holder (just like a big gasworks). The pressure remains constant because the reservoir can float up and down to change volume. If it over-fills and then over-pressures itself, it just blows out the water seal.
Another way is to make the water-drip feed under low pressure. No more water can get in there until the pressure drops. This is how car lamps and miner's cap lamps used to work. BTW - you can stil buy acetylene generators and supplies from a caving shop.
Monthly ? That's either a tiny cylinder, or you're commercial.
I have no idea what my acetylene costs me. I use far more oxygen, and renting the bottles costs more than the gas does, at any sort of "UK hobbyist" rates.
-- Die Gotterspammerung - Junkmail of the Gods
Reply to
Andy Dingley
You must really consume a heap of acetylene in your home shop then to want to spend the big $$ and go through the paian it is to maintain a generator system. Why not just get a larger cylinder or add an additional cylinder or two. I personally don;t think a acetylene genmerator is cut out to be used in a home shop environment no matter how much gas you may consume. Visit my website:
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expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy.
Reply to
Roy

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