On Mon, 09 Jan 2006 23:54:37 -0800, Enoch Root
wrote:
Bruce L. Bergman wrote:
On Sun, 08 Jan 2006 22:43:32 -0800, Enoch Root
wrote:
40cf c2h2 tank 200psi (missing knob, I used a wrench to test)
That is more commonly referred to as a "B" size Acetylene tank. And
they don't come with a knob, you use a little dogbone wrench to open
them. Put a piece of small chain in the other hole and loop it around
the regulator to keep the wrench from wandering away.
Heh. Now I can say I know more about something than the guy I bought it
from.
The trick is not to let the seller know /you/ know until after
you've agreed on a fair price - they might smell blood and raise the
price out of the reasonable range. Then you have to explain the next
paragraph to them.
A fair price to you may sound low compared to retail prices for the
same item new - but it isn't new, and has no warranty. If it turns
out later to have a problem, you paid too much for something that'll
have to be tossed, or need replacement parts, or to be professionally
repaired, so in the end it all works out.
Sellers balk when I offer them a buck for an old fire extinguisher -
but I'm buying it to use it, not for a room decoration. I have to pay
$15 to $20 for a hydrotest and recharge, so if they want $15 for one
that's out of hydro (usually 6 years on a CO2, 12 on a Dry Chem) they
just made it cheaper to buy a new one.
And you do NOT want that Acetone level to run low inside the
cylinder, or the pressure past the regulator to EVER go above 15 PSI.
Google "Acetylene Deflagration" and learn. (It just decides to go
BOOM!!! and levels the garage - this is not good...)
Jeez. I think I've not been cautious enough. Thanks.
Everyone needs a wakeup call sometimes - preferably not a fatal one.
Where it gets difficult is in transporting tanks in a car - you MUST
keep the cylinders strapped down while moving them, and moving them
upright is better because the Acetylene cylinders have a heat
sensitive fusible plug in the valve, and if it pops you don't want all
the Acetone coming out too. The oxygen cylinders have a rupture disk
as a relief valve, so they let out their contents when full cylinders
are overheated and the pressure goes up past the burst point.
Keep the cylinders cool, and allow for lots of ventilation. Store
them at home out of the sun, secured upright. Most suppliers will not
load the bottles if you don't have an open truck - but you may not own
a truck, so improvise to get it as safe as possible. Don't close the
trunk all the way - put an empty cardboard box over the latch and
strap the lid down leaving a big gap for ventilation. Load the
cylinders up, strap them down, go straight to the welding supply to
get full bottles, and straight home to unload them. No parking in the
sun for an hour at the market.
There are photos out there of wonderful free-form metal sculptures -
that used to be a car or van before a cylinder went off inside them...
"Awesome Blossom", indeed. ;-) The Welding Supply probably has one
or two on the wall to point at when people wonder why they refused.
Just google'd up a very recent example for you -
http://home.hamptonroads.com/stories...7711&ran=95047
HFatal car explosion likely caused by acetylene tank in trunk
H By MATTHEW ROY, The Virginian-Pilot
H© January 6, 2006 | Last updated 11:12 PM Jan. 5
H
HNORFOLK — An explosion that killed a man and reduced a car to a
Hscorched shell on Dec. 24 was likely an accident caused by an
Hacetylene tank in the trunk, fire officials said Thursday.
HThey also released the identity of the victim, who had been in
Hthe car, as Errol Tony Mack, 34, of Virginia Beach.
H
HHe was killed when the car blew up near the Kappatal Cuts salon
Hin the 1400 block of Ballentine Blvd. at 4:30 p.m. on Christmas
HEve. The car was engulfed in flames when firefighters arrived.
H
HMack was involved in some sort of heating, ventilation and air-
Hconditioning work, said Battalion Chief Bruce Evans of Norfolk
HFire-Rescue. Acetylene is used by welders and plumbers to fuel
Htorches.
H
HIt appears that acetylene gas leaked into the trunk and was
Hignited, possibly by an electrical spark, he said.
HEvidence showed the explosion occurred in the rear of the car.
H
HThe state medical examiner’s office identified Mack and found
Hthat he was killed by blunt-force trauma and “heat inhalation,”
Haccording to Evans.
H
HThe findings are preliminary, and items from the car have been
Hsent to a Bureau of Alcohol, Tobacco, Firearms and Explosives
Hlaboratory for tests, which may take several weeks.
H
HReach Matthew Roy at (757) 446-2540 or .
And that was probably a 'MC' 10CF Acetylene & 20CF Oxygen
'Porta-Tote' size torch kit, very popular for silver-brazing HVACR
linesets. Very easy to toss in the trunk and forget all about...
And running Acetylene through copper tubing or high-copper alloys of
bronze or aluminum bronze can form acetylide oxides that are explosive
and unstable - not good. The bronze alloy they use for the regulators
tips and fittings is deliberately chosen. Same thing for any oil or
grease in the Oxygen system.
The regulator lines have some kind of sintered metal wall inside, and
the handle and tips are just of brass (except the top of the tip, which
appears to be copper)... maybe ok?
If it's sold for Acetylene service, it will be made of one of the
proper brass or bronze alloys. They all know the rules - but you
might not know yet, which could be really dangerous, because when you
don't follow these rules someone can get killed. This isn't
frivolous like a 55MPH speed limit, No lip service allowed.
No Experimenting, No Improvising With Gas Regulators, Fittings,
Hoses or Lines. Buy the right stuff. No using a chunk of copper
tubing to extend the acetylene line, or using one of your old shop air
hoses that has air tool oil or compressor oil carry-over residues
inside as a makeshift oxygen line...
If you buy a used oxygen regulator and even suspect that it's not
squeaky clean inside, have the welding supply service and clean it.
If that Acetylene regulator keeps 'sticking' like that, get it checked
out, too. If some dope did something stupid like cross-threaded the
diaphragm cover onto the main body, it could come apart with some
serious energy behind it.
-- Bruce --
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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