Cutting Gas Cylinders Open Safely - HELP

[Screwdriver]

Only ever done it the once and after multiple water purges I filled it with C02 as an extra step, how I knew it was full of C02 I've no idea but pumped some in for a while thinking that the less air in there the better. Was still nervous despite being convinced there was no gas remaining.

I don't think it's something to be scared of, just take sensible precautions. There are a number of potential pitfalls with chopping open any fuel vessel but so long as you know what they are, you can mitigate those dangers and reduce the possibility of an accident to almost zero.

It never really is zero of course.

 

[daleyd]

I've belted the valves off (empty) cylinders with a sledge hammer to scrap them. The neck on the bottle is around 3/4" but the tail end of the brass valve reduces this port down to around 5mm

My mate was a welder at a local trailer place back in 80’s early 90’s and their gas was stored outside in a tin sheet outbuilding/lean to - he said there was some hefty dents in the roof where the lads had smacked the valves off empty cylinders

 

[The_Yellow_Ardvark]

 

[8ob]

The problem with oxy going up is it aides combustion, in a building fire this can be quite dramatic. Many moons ago there was a fire at a fab shop in Ash ( Always Welding) , the O/A bottles were engulfed and the neck of one of them went through the roof of a house in Mytchett which is about two miles away as the crow flies.


Bob

 

[Screwdriver]

Meh. They do a proper job in Russia...

Turn the sound up.

My favourite one is at 2.50. So many to choose from though...

 

[Shox Dr]

The problem with oxy going up is it aides combustion, in a building fire this can be quite dramatic. Many moons ago there was a fire at a fab shop in Ash ( Always Welding) , the O/A bottles were engulfed and the neck of one of them went through the roof of a house in Mytchett which is about two miles away as the crow flies.


Bob

There’s a video on ut, of a bottle storage fire in America By the side of a large road network with multiple flyoverS, there’s Bottles raining down like stair rods. You need less than 5% fir that stuff to BANG

 

[Seadog]

My favourite one is at 2.50. So many to choose from though...

I wonder which country that landed in?

There are some incredibly thick people around, as is evident from the video.

 

[maz0]

Meh. They do a proper job in Russia...

Turn the sound up.

My favourite one is at 2.50. So many to choose from though...

Several years of watching gorey videos online has taught me to never stand anywhere near anything thats exploding, even if you think your far enough away.

 

[The_Yellow_Ardvark]

I wonder which country that landed in?

There are some incredibly thick people around, as is evident from the video.

I wish I could publicly post the image of the remains of an arm on a engineer.

He had been doing the job for years. Fallen into the trap of taking short cuts, to speed the job up.

This time, he left the safety pin out on a CO2 gas suppression system. It deployed.

CO2 is forced along the pipe as a liquid, until the nozzles. Where it boils to a gas.

You can guess the damage to him.

 

[maz0]

I wish I could publicly post the image of the remains of an arm on a engineer.

He had been doing the job for years. Fallen into the trap of taking short cuts, to speed the job up.

This time, he left the safety pin out on a CO2 gas suppression system. It deployed.

CO2 is forced along the pipe as a liquid, until the nozzles. Where it boils to a gas.

You can guess the damage to him.

Didn’t they reckon the explosion at RAF faulds was an engineer removing a detonator with a brass chisel instead of the regulated wooden ones? Damn engineers and their shortcuts.

 

[The_Yellow_Ardvark]

Didn’t they reckon the explosion at RAF faulds was an engineer removing a detonator with a brass chisel instead of the regulated wooden ones? Damn engineers and their shortcuts.

Yes, they think it was wrong tools.

I understand it made a bang. But the water put the fires out.

https://en.wikipedia.org/wiki/RAF_Fauld_explosion

 

[Hopefuldave]

Well, maybe a very small jet. Each Concorde engine on afterburner was 17,000 kgf ( 170 kN ).
Each Space Shuttle solid rocket booster: 1.2 Million kgf
At the smaller end of the scale, the rocket motor in a missile such as a Sidewinder is 1,800 kgf, which is getting close to the 650 kgf of the flying gas bottle.

Last workplace holds an annual bottle rocket competition at the other end of th e spectrum - 2 litre fizzy drink bottle pumped to 10 Bar takes off quite quickly with about 75 pounds / 300N? of thrust pushing a kilogram of water out the back
Got the one Elaine and I made to fly about 250 metres before it touched down! She's quite techy and modeled various reaction masses (the water) against the reduction in mass as it was expelled - be interesting to do the same for a gas bottle, but the maths would take me a week!

Dave H. (the other one)

 

[Parm]

I was in a pub once talking with an old Irish guy who did demolitions. He reckoned they used to get the oxy bottles once they were empty, lay them on a bit of channel propped on a beer crate and whack the valve off with a sledge! Went like a missile he said. They used to do it onto the river, he reckoned there was hundreds of em' in there!!

I’d say that’s a bit of a tall story, once they are empty there is little to no pressure inside.

Whacking the valve off won’t make they go anywhere

 

[Maker]

Last workplace holds an annual bottle rocket competition at the other end of th e spectrum - 2 litre fizzy drink bottle pumped to 10 Bar takes off quite quickly with about 75 pounds / 300N? of thrust pushing a kilogram of water out the back
Got the one Elaine and I made to fly about 250 metres before it touched down! She's quite techy and modeled various reaction masses (the water) against the reduction in mass as it was expelled - be interesting to do the same for a gas bottle, but the maths would take me a week!

Dave H. (the other one)

I used to love bottle rockets when I was younger, don't know why I haven't made one with a proper nozzle since getting a lathe.

 

[Parm]

Just doing a quick bit of maths if I have it right if you knock the neck off a W size bottle let's say you have a 3/4" hole with 220bar coming out of that's 220*14.7*.442= 1429pounds or 649kg of thrust shoving 88KG of bottle. I'd say she's gonna fly!

Full ones that go wrong certainly do fly

At home I’ve got pictures of the VA Tech Parson Peebles factory in Edinburgh. Experienced a massive fire about 20 years ago

All sorts of gas bottles exploded

The holes they left in walls and machinery were incredible.

We were on site managing the Asbestos clean up

Place was one hell of a mess

 

[Hopefuldave]

I used to love bottle rockets when I was younger, don't know why I haven't made one with a proper nozzle since getting a lathe.

I'm pretty sure I saw the necessary Fittings to 3D print on Thingiverse, too...

Dave H. (the other one)

 

[Hopefuldave]

I’d say that’s a bit of a tall story, once they are empty there is little to no pressure inside.

Whacking the valve off won’t make they go anywhere

I was taught, moons ago, that like guns they're never "empty"... So treat 'em that way.

Dave H. (the other one)

 

[cheb]

I don't know if gas bottle valves are like dive cylinder valves, but newer dive valves are designed to leave a couple of bar pressure inside the bottle to prevent corrosion. The gas having been filtered and dried as it's pumped in. The seal with an O ring, once the valve is slackened the pressurised gas escapes and you can unscrew the valve by hand.

Caveat: This is based on my personal experience of a few diving air cylinders and valves, it might not apply to every single dive cylinder and valve made since Fréminet's time.

 

[Parm]

I was taught, moons ago, that like guns they're never "empty"... So treat 'em that way.

Dave H. (the other one)

This is very true, aalways treat with respect. ALWAYS. General rules for any pressure vessel

But when empty they won’t launch like a projectile if the valve is knocked as they won’t make much pressure inside

 

[Fraserb]

I used to love bottle rockets when I was younger, don't know why I haven't made one with a proper nozzle since getting a lathe.

Guess what im off to do now.