Fueling from plastic containers

"Roger" wrote in message
...
On Mon, 28 Mar 2005 18:40:03 GMT, "Ralph Nesbitt"
wrote:


"Bertie the Bunyip" wrote in message
...
How about it Ralph? Know anything abou this?

He is correct re static electricity causeing fires while filling
containers
with gasoline, especially Plastic one's. The dispenser nozzle is
grounded,
but there is no continuity of ground to small containers, ie 5 gallons or
less.

I'm not so sure it's especially plastic ones. In the "old days" we
refueled tractors out of 5 gallon metal cans. You learned early on to
*always* put the can against the metal funnel and never just pour down
into a funnel.

Metal to metal forms a ground to the tractor alowing any static electricity
to bleed off.

I only know of two fires, as I mentioned in another post, but I
understand they were fairly common. However out in an open field, you
just put the cap back on the tank and carried the can away from the
tractor. That is unless you splashed gas all over. The putting out
the fire became a much more hurried proposition.

Gas fumes are strange animals.
My dad was getting some work done at the local welding shop. They
were working on a tanker (tractor trailer) at the time. They had
filled and drained the tanker twice using water to flush it out.

The tank was drained when they struck an arc. It blew out part of the
back end of the trailer. Unfortunately that caused the trailer to
jump forward and there was a guy standing on the rear of the tractor.
Whether it sheared off the 5th wheel or what happened I'm not sure,
but it squashed the guy between the tank and back of the cab like a
bug

Common practice is to fill any container with water & leave the water in it
while doing "Hot Work" on any container/vessel/tank that has contained a
"Flamable Liquid" irrespective of class. Gasoline vapours between the LEL &
UEL have the explosive potential of 1 stick of dynamite per 10 cubic feet of
vapours. There are more people injure/killed doing/being in the vicinity of
hot work on 55 gallon drums that have contained flamable liquids than any
other cause associated with hot work on flamable liquid containers.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Ralph Nesbitt
Professional FD/CFR/ARFF Type
Posting From ADA

"Morgans" wrote in message
...

I do know that gas fumes are more dangerous in very damp, humid settings,
even when outdoors. I remember a pile of wet leaves jumping off the
ground
a couple of feet. I also know a guy that was severely burned, trying to
light a wet brush pile, when the fumes jumped back. It seems they hold to
the ground more, or are more concentrated.

Couple of personal anecdotes, here. I remember working as a line boy at
Boeing Field back in the 50's. When we would take the tanker down to "The
Pits" to refill it, we would connect the ground cable, climb up on top, open
the hatch, swing the "elephant pecker" (delivery hose - about 3" diameter)
over the hatch and open the valve 90°. The fuel, either 80/87, 91/96 or
115/145 avgas would spew out of the hose into the tank at a hundred gallons
per minute.

After just a few seconds of flow, you could look down and see static sparks
jumping from the hose to the lip of the hatch. The vapors were too rich to
burn because they were coming out of the hatch as fast as the fuel ran in.
We would swing the hose over until it touched the rim to stop them, but
nobody worried too much. All us line boys were in our teens and immortal.

Years later when I was in the Fire Department, there was an arson on Capitol
Hill in Seattle. A fellow spread five gallons of gas throughout a two-story,
ten unit apartment house. He lit a match when he got to the front door and
threw it in. It was a snowy December day. His efforts were rewarded with a
fire in the hallway, which was quickly extinguished.

The next June, he tried it again. When he struck the match, the fumes
immediately gave a Shrek-sized burp. When we arrived, the entire apartment
house was in flames. I'll always remember the expression on the fellow's
face . . . as he hung there on the power pole across the street, one of
those steel climbing steps protruding from his chest.

Those were the days.

Rich S.

On Mon, 28 Mar 2005 21:04:16 -0800, "Rich S."
wrote:

Couple of personal anecdotes, here.

I've got one too. I remember an assembly in High School in which some
fuel/fire expert came to speak to us. He had a rig that looked a lot
like a ski jump. It was about two feet worth of ramp and had a ball
of cotton tied to the top, and a candle lit at the base.

He lit the candle and then doused the cotton ball with just a few
drops of gasoline he carried in a sealed beaker. Then he walked
around talking about how the fumes were heavier than air while we all
stared at this contraption.

About two minutes later while this guy was still talking, the candle
suddenly lit up brighter and a little puff of flame began to climb up
the ramp. It moved up the ramp and the cotton ball burst into flame.

I never forgot that, what a great demonstration of how the fumes
descend into low spots.

Corky Scott

"Rich S." wrote in message
...
"Morgans" wrote in message
...

I do know that gas fumes are more dangerous in very damp, humid
settings,
even when outdoors. I remember a pile of wet leaves jumping off the
ground
a couple of feet. I also know a guy that was severely burned, trying to
light a wet brush pile, when the fumes jumped back. It seems they hold
to
the ground more, or are more concentrated.

Couple of personal anecdotes, here. I remember working as a line boy at
Boeing Field back in the 50's. When we would take the tanker down to "The
Pits" to refill it, we would connect the ground cable, climb up on top,
open
the hatch, swing the "elephant pecker" (delivery hose - about 3" diameter)
over the hatch and open the valve 90°. The fuel, either 80/87, 91/96 or
115/145 avgas would spew out of the hose into the tank at a hundred
gallons
per minute.

After just a few seconds of flow, you could look down and see static
sparks
jumping from the hose to the lip of the hatch. The vapors were too rich to
burn because they were coming out of the hatch as fast as the fuel ran in.
We would swing the hose over until it touched the rim to stop them, but
nobody worried too much. All us line boys were in our teens and immortal.

The same situation with JP4/Jet A jenerally results in an explosion & fire.

Years later when I was in the Fire Department, there was an arson on
Capitol
Hill in Seattle. A fellow spread five gallons of gas throughout a
two-story,
ten unit apartment house. He lit a match when he got to the front door and
threw it in. It was a snowy December day. His efforts were rewarded with a
fire in the hallway, which was quickly extinguished.

The next June, he tried it again. When he struck the match, the fumes
immediately gave a Shrek-sized burp. When we arrived, the entire apartment
house was in flames. I'll always remember the expression on the fellow's
face . . . as he hung there on the power pole across the street, one of
those steel climbing steps protruding from his chest.

Those were the days.

Rich S.

Lower temp kept the vapors from rising/spreading resulting in vapors being
closer to LEL. Higher Temp caused vapors to rise/spread resulting in vapors
being closer to UEL. This resulted in faster flame spread, i.e. a
deflagration nearing an explosion.
Ralph Nesbitt
Professional FD/CFR/ARFF Type
Posting From ADA

On Mon, 28 Mar 2005 23:43:14 -0500, "Morgans"
wrote:


"Roger" wrote

The tank was drained when they struck an arc. It blew out part of the
back end of the trailer. Unfortunately that caused the trailer to
jump forward and there was a guy standing on the rear of the tractor.
Whether it sheared off the 5th wheel or what happened I'm not sure,
but it squashed the guy between the tank and back of the cab like a
bug

Bad news. What is the right way to weld something that large? I know with
something small, like a gas tank, or can, you fill it with inert gas to
displace the oxygen. How about the tanker? Dry ice, to make carbon
dioxide?

I do know that gas fumes are more dangerous in very damp, humid settings,
even when outdoors. I remember a pile of wet leaves jumping off the ground
a couple of feet. I also know a guy that was severely burned, trying to
light a wet brush pile, when the fumes jumped back. It seems they hold to
the ground more, or are more concentrated.
--

There are some other things at work though.

Old, compacted brush piles and even leaves decompose, creating
Methane. After a damp spell with little of no wind the methane can
accumulate in the brush pile, or under the leaves. As Methane has a
rather wide range between the LEL and UEL it can range from startling
to spectacular.

A good many barns have been lost to this. I know of one where the
loose hay was put up without proper drying. He was trying to get the
hay in before it rained. About a month later the barn was gone.
I've "turned" loose hay in a barn and it's ...more than a little work.
The only way to put it is "It's a real bitch!".

Loose is a misnomer, or it is after the hay has been in there for a
while. It packs every bit as tight as any bale. Using "hay forks"
(Interesting and very dangerous piece of machinery) "Hay Forks" come
in various shapes and sizes, but the ones we had were a two legged
affair about 4' tall and about 2 1/2 feet between the legs. The tips
of the legs were sharply pointed had hooks about 4 inches above the
points that pivoted in flush, or stuck out about 3 to 4 inches.

You dropped these suckers into the hay from maybe 20 feet, but more
often than not you ended up, jumping up and down on the cross bar to
drive them into the hay. They don't sound like much, what with loose
hay, but they'd pick up more than an 1 1/2" rope could handle. Easily
one to two tons which meant splicing a rope if you didn't break
something more serious.

After getting down maybe 6 or 8 feet into the hay I've seen the
temperature so high you needed gloves. When you find it that hot you
know you came within a day or two of losing your barn and we had one
very large barn. It was 40' to the peak, over 100' long and I think
about 40' from front to back and not a nail in it except for new
siding.

Speaking of brush piles... We live well out into the rural
subdivisions. There is a lot of construction and rebuilding going on.
We can get permits to burn brush piles by just calling the DNR, but
construction materials are to be properly disposed of. Some how a
lot of scrap lumber manages to make its way into most brush piles.

One neighbor had a very large brush pile that was probably 50% scrap.
Now, he's right out in the open as opposed to our yard which has woods
on two sides.

With all that scrap and fresh brush the pile was rather open. Big, but
open. They apparently used gas instead of kerosene to get it going.
They mush have lit a rag on a stick and threw it as every one still
had their eyebrows, but that was louder than a couple sticks of
dynamite. Shook the whole neighborhood. I'm surprised they didn't
have to put the brush pile back together, but man what a fire when
that thing got going. OTOH the top of the pile was higher than the
peak of our roof.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com




Another neighbor had a straw pile next to the barn. He'd have been OK
had the pile been out in the barn yard, but not against the barn.
Moisture collected and down deep inside the pile it got *very* hot.
Jim in NC