Oxygen and Acetylene bottles

[Scrub Puller]

Yair . . . Sorry Dualie. I missed your #16 post up top . . . what you say makes a lot of sense. Maybe our gas bombs weren't the opimum mix allowing excess acetylene to ignite the grass . . . we used to get a neutral flame and then snuff it on the ground.

Cheers.

 

[hvy 1ton]

Not the first time i've been wrong, won't be the last. Dualie disagreeing with me is never a good sign.

 

[Dualie]

I used to know the science behind why it was such a flash bang and no burn. something to do with carbon content and molecule exchange its the like. that was years ago in as science class i was more more enamored with the female students than the boring blackboard.

 

[JDOFMEMI]

I had heard once that the reason for the lack of a fire after the explosion is due to the violent explosion using up all of the free oxygen, leaving none to support combustion after the event. By the time fresh oxygen reaches the site of the blast, the temp has dropped enough that it will not light a fire.

This is the same principal used sometimes on oilwell blowouts. They set off an explosion to put out the fire in order to be able to close the well off.

 

[Scrub Puller]

Yair . . . gotcha JDOFMEMI, this has been educational.

Cheers.

 

[Dualie]

i was trying to allude to that some how JDOFMEMI but somehow what i wrote is what came out.

 

[capp48]

Without that powertank bottle secured to a stand I see nothing but trouble. That open guard around the gauges isn't going to stop much damage. Especially when used off roading in uneven, broken, rocky ground. High pressure tank. Little protection aroung gauges and regulator and a tank ready to be knocked over. Mix that with off roading and beer! Ya boy! Now I'm not just cracking on the off road people...But what the hay? Why not. Hahah!

 

[OzDozer]

There have been several deaths in Australia, caused by gas explosions in vehicles, over the last decade or more, due to either LPG (LP or propane to our U.S. friends) or oxy-acetylene bottles that leaked and exploded when the remote unlocking was activated.
Plumbers vans are the most common victims. Some vehicle owners were dead lucky and avoided death/injury completely by not being close enough when the explosion occurred.

There usually has to be some kind of additional fuel feed and ignition to have a fire - either petrol (gasoline) or other inflammables added to the mix.
An explosion creates a massive oxygen-depleted vacuum that will snuff out fires. This is the principle used in extinguishing major oil-field fires that cannot be put out any other way.

There is currently a push on, to install gas bottle holding compartments in work vehicles, that are separate from the vehicles interior, and vented to the atmosphere.
All caravans (trailer homes) and motorhomes already have this statutory requirement for all larger portable gas bottles.
Interestingly, the van involved in the Chelsea Heights, QLD., explosion appears to have had a separate bottle compartment fitted (YouTube video, 1:27 - 1:55).

Mulgrave, Victoria, Australia, gas explosion - fatal - http://www.news.com.au/national-old...odes-in-mulgrave/story-e6frfkvr-1226219643781

Chelsea Heights, Queensland, Australia - gas explosion - no injuries - http://www.youtube.com/watch?v=VSbohasKM_Q

Chelsea Heights gas explosion photo gallery - http://www.cfaconnect.net.au/pics-499.html

Parap, Northern Territory, Australia - gas explosion - fatal - http://www.ntnews.com.au/article/2011/12/16/278605_ntnews.html

 

[OzDozer]

Here's a report on another fatal propane-gas-caused explosion in a plumbers van, in 1997, in North Ryde, Sydney, Australia.

http://www.testsafe.com.au/latest_news/november_2004/north_ryde_gas_explosion.pdf

Incidentally, the plumber who owned the van involved in the Chelsea Heights explosion was fined AU$25,000! - and the resultant major safety investigation found;

• The owner failed to ensure a safety-cabinet in which the acetylene was stored in the vehicle, was airtight;
• The owner failed to ensure the cabinet was properly vented to the outside of the vehicle;
• The owner failed to ensure employee/s conducted a soapy water test to check the cylinders were not leaking before he/they loaded the cylinders into the vehicle.

I wouldn't like to think what his insurance premiums are today! - if he's still in business!

 

[alco]

I disagree with SP about leaving cylinders with the gauges fixed to them for the simple reason that if anything falls on the gauges or if the cylinder itself falls over for whatever reason it could knock off the complete valve/gauge assembly thus venting the cylinder whether or not the valve is in the OFF position or not. I have personally seen this happen twice. If a cylinder has the gauges off and the metal safety cap installed then I have NO PROBLEM with it lying down so long as it's properly secured against rolling around. That opinion has brought me into conflict with numerous Safety germs over the recent years.

I agree wholeheartedly with Nige. I wasn't present when it happened, but I have personally seen the aftermath of a K size oxygen cylinder falling over and having the valve knocked off. It took the concrete block wall in front of it with it, and narrowly missed people on the other side. Not pleasant at all.

 

[Karl Robbers]

I realise this is an older thread, but will comment anyway.
Acetylene has a flammability rating from 1 to 99% meaning it will burn at concentrations between 1 to 99% in air. That is one of the widest flammability ratings you will ever find. LPG has a far narrower rating - ever tried to light a gas barbeque on a windy day?
It is now illegal in all Australian states as far as I am aware, to carry a gas cylinder of any type in an enclosed vehicle, sedan, wagon or van. You are however allowed to carry cylinders on their side, but acetylene should be stood upright for at least 30 minutes before use to allow the acetone to settle.
Acetylene is a safer gas than LPG in some ways given that it is lighter than air and will disperse, LPG is heavier and will collect in hollows and basements. Acetylene will however ignite at the drop of a hat - remember the flammability rating, it hardly needs oxygen to burn.
I haven't seen a metal safety cap in the last 25 years. I still see cylinders threaded for them, but have never seen a cap. Ever.
The fact that does surprise me though is that there is no manual isolation valve on LPG powered car installations here. I thought that would be the first thing you would do, but apparently not.

 

[Randy88]

Ok guys here's a few questions while on the subject, I'm slightly off topic here, I'm referring to my service truck, not a van or suv where your in the same compartment as a the tanks, I'm told its just as safe to transport O2 cylinders with the gauge's on them, "IF" the safety cap that fits around the whole gauge assembly that covers them, as it is to have the gauge removed with a standard safety cap on, is this true or just bull?? Both tanks being fastened or strapped down.

Next one is, since I use LP gas on my torch, I've yet to see any safety cap on any lp cylinder that's put on DOT approved tanks and its safer to fasten the tank down and leave the gauge on it, than have the tank just sitting unfastened without a gauge on it? Both statements came from a DOT officer, was his assessment accurate or not?

Both my LP and my O2 tanks are strapped, actually chained upright in a compartment with the gauges on them and I'm told that's perfectly legal according to the DOT, the only thing safer I could do was put the gauge cover over the O2 gauge and its not a requirement by the federal reg's I'm told but "might" add a degree of safety in the event of a collision, they didn't care about the LP tank's gauges at all, as long as it chained upright and both cylinders are in their own compartment.

Last question anyone have any experience with Propylene instead of LP or acetylene, how explosive is it compared to LP gas and acetylene?

 

[Nige]

For metal safety caps I'm like Karl, haven't seen one in years. This is the latest "valve protector" our gas supplier uses. It will still NOT protect gauges though, and neither is it designed to.
We have a policy that if we are transporting compressed gas cylinders the gauges must come off.
No problem about transporting cylinders lying down but they must be secured at least as well as they would be secured if transported vertically, and we also have the "30m minute rule" regarding acetylene cylinder usage if it has been transported lying down.

 

[old-iron-habit]

In just looking at the current OSHA regs in the USA I found the following. In transportation by mechanical means all compressed flammable liquids are required to have the end use devices removed, be secured for transport, and have the compressed cylinder manufacturers safety equipment installed. Any vehicle not specifically designed for transportation of said products can not exceed 440 lbs of product on or in the vehicle. In a separate paragraph it talks about any product that is used to enhance combustion will be classified as a combustable when stored in conjunction with the flammable product. In other words the oxygen bottle classifies as combustable when stored alongside the actelene. If carrying a set of tanks on a forklift or hoisting on a job site they need to have the safety covers on to be in compliance. Our company safety policies are to secure actelene in the lay down position in the pickups and to stand upright for 30 minutes minimum before using.

MN DOT shows the same 440 lb allowed load as OSHA. I could not find anything specific about the caps/covers. Only mentioned properly and safely secured. Leaves the lawsuit open for interpretation after the accident.

 

[Randy88]

Nige, we have the covers here that cover the entire gauge assembly and only the hose comes out, two halves fold down to turn the tank on and off and then the two halves fold up and are secured with a hasp, never seen anything for acetylene but I won't use acetylene anyhow. I've never seen the version you posted the picture of just now unless there's more to them for covers not included in the pictures?

Just out of curiosity, I'm going to ask the insurance company what they deem, its been a few years since I've asked, the last time I did, I was told whatever the federal reg's required was fine with them, at that time they considered the compartment the tanks were in as the "safety" device was the explanation I was given, but come to think of it, the DOT hasn't stopped that truck in the last few years and done a full blown inspection of it either, they've gotten all the rest though.

 

[Nige]

Randy, The picture above is exactly how the cylinder comes from the gas supplier - there is nothing more to it. That cylinder is empty BTW, that's why there is no plastic shrink-wrap seal on the valve.
As you can see the protector for the valve screws on to the same thread that the old-style steel screw-on cover did.
If you look at the cylinder on the left of the photo you can see how wide the base of the protector is. It covers the whole valve assembly and then some.
I think they're pretty nifty but that's just IMHO.

Post some pictures of your cover that covers the whole gauge assembly please.

 

[Scrub Puller]

Yair . . . Karl Robbers

It is now illegal in all Australian states as far as I am aware, to carry a gas cylinder of any type in an enclosed vehicle, sedan, wagon or van.

I wonder what the situation is regarding folks picking up barbeque gas from Bunning's?

Cheers.

 

[Randy88]

Nige, I've made a few calls, turns out I'm wrong, the caps I was thinking of we had way back when wasn't a factory made one, a local shop made it for dad at the time to cover the gauge as well, but wasn't for anything certified per say, just safety around the farm having to transport the torch around and dad didn't want the gauges taken off, I always thought it was a purchased cap, not till now did I find out it wasn't, sorry about my wrong thinking. Dad thought the local shop made many of them for farmers and contractors back over 40 years ago just for that reason. Nobody seems to know what ever happened to the cap, dad hadn't seen it in over 25 years.

Dad thought the shop who built them, used the standard safety cap that hinged and opened up with a hasp, and welded a pressed bowl in two halves onto that cap, there were two hasps on top to open it up and also lock it shut and the hose stuck out the end, he said it was crude but effective and most had them for the O2 tanks.

 

[Randy88]

Nige, the insurance company called back, and I also talked to the DOT people today, both gave the same story, if the tanks are in a compartment, chained or strapped so they can't move, for travel purpose's the regulators don't have to be removed and there doesn't need to be a cap on the O2 tank, as long as I don't exceed the 440 lb rule they are considered MOT's or materials of the trade. I never asked about if you exceed the 440 lb rule, how the rules change, I never have or probably ever will exceed the weight so it doesn't apply to me.

I only asked about LP gas tanks, not acetylene, its what I have on the service truck at all times, we use 20-40 lb tanks of LP for my engine heaters on a few machines in cold weather, and can have up to a half dozen of them on the truck at any one time, if they are not in a compartment, they have to be strapped down in some fashion to prevent movement, also they have to be DOT approved tanks.

The only thing I forgot to ask was how things change when any tanks or materials are placed in the cab or where the driver is at, so I can't tell you what the law states if you have a van or suv.

 

[95zIV]

Nige,

Here are the safety caps that are being talked about on this side of the pond, there is also another version of the high pressure cap that slides up and tilts to allow access to the valve:

https://www.kimballmidwest.com/Catalog/CatalogIndex.aspx?p=6.628.591.4861

http://www.usasafety.com/lockable-c...ap-p-61.html?gclid=CNfBlvKe5L4CFQJqMgod5XcAsw

Also, as I understand it, when the bottles are to be carried in a enclosed cabinet on a truck, that cabinet is supposed to be vented to allow air to circulate through and dissipate any gases that may leak out of a improperly closed valve.