Fire at boatyard at Osney

[alan_fincher]

Guardian article

[Guest]

Oh dear - breathtaking complacency. No - this is not nonsense. When a propane or butane cylinder is exposed to fire, the contents will heat up and the internal pressure will rise rapidly . This will cause the pressure relief valve to operate and the gas that issues forth will promptly ignite, adding to the fun and heat. As the cylinder heats up, it weakens. It will very rapidly weaken to the point that when the internal pressure is high enough, the weakened cylinder wall WILL rupture expolosively, the pressure relief valve simply being unable to vent sufficient gas to moderate the pressure inside the cylinder.

 

When the cylider ruptures, the internal pressure falls to zero and the superheated contents will flash into vapour and immediately ignite, creating a fireball that will incinerate anything unfortunate enough to be nearby. This is the classic BLEVE that other contributors have mentioned.This process is NOT unusual or difficult to provoke. If you put any gas cylinder into a bonfire that is hot enough, it WILL explode with considerable force. It is this explosion that projects the fragments of cylinder (i.e. red-hot shrapnel) at high speed for 100s of metres, not the comparitively insignificant effect of the jet of gas escaping from the presure releif valve. If the base weld of the cylinder fails, the whole thing can act like a rocket and fly for considerable distances.This is quite sufficient to destroy a building. I have personally seen examples where an aerosol-size can of blowtorch fuel has exploded in this fashion - it was sufficient to lift and move the roof of the building where the explosion occurred. Please see below:

 

 

 

You wouldn't want to be near that little love when it went off. Just in case your'e wondering, I have 30 years experience as a Fire Officer and was a specialist Hazmats Officer who dealt with many, many cylinder incidents over the course of my career. So the message is....these things ARE dangerous and they WILL explode if exposed to fire. Do not be complacent, because they WILL bite, and bite hard.

Absolutely I had a resident on a caravan site who chucked a gas canister on a bonfire, the resulting blast put him in hospital, with a very damaged leg. Not the brightest spark you might say!

[ditchcrawler]

 

Oh dear - breathtaking complacency. No - this is not nonsense. When a propane or butane cylinder is exposed to fire, the contents will heat up and the internal pressure will rise rapidly . This will cause the pressure relief valve to operate and the gas that issues forth will promptly ignite, adding to the fun and heat. As the cylinder heats up, it weakens. It will very rapidly weaken to the point that when the internal pressure is high enough, the weakened cylinder wall WILL rupture expolosively, the pressure relief valve simply being unable to vent sufficient gas to moderate the pressure inside the cylinder.

 

When the cylider ruptures, the internal pressure falls to zero and the superheated contents will flash into vapour and immediately ignite, creating a fireball that will incinerate anything unfortunate enough to be nearby. This is the classic BLEVE that other contributors have mentioned.This process is NOT unusual or difficult to provoke. If you put any gas cylinder into a bonfire that is hot enough, it WILL explode with considerable force. It is this explosion that projects the fragments of cylinder (i.e. red-hot shrapnel) at high speed for 100s of metres, not the comparitively insignificant effect of the jet of gas escaping from the presure releif valve. If the base weld of the cylinder fails, the whole thing can act like a rocket and fly for considerable distances.This is quite sufficient to destroy a building. I have personally seen examples where an aerosol-size can of blowtorch fuel has exploded in this fashion - it was sufficient to lift and move the roof of the building where the explosion occurred. Please see below:

 

 

You wouldn't want to be near that little love when it went off. Just in case your'e wondering, I have 30 years experience as a Fire Officer and was a specialist Hazmats Officer who dealt with many, many cylinder incidents over the course of my career. So the message is....these things ARE dangerous and they WILL explode if exposed to fire. Do not be complacent, because they WILL bite, and bite hard.

When we did our firefighting courses one of the demonstrations was to pierce a small Camping Gaz type cylinder and light the escaping gas, all was fine until the pressure inside reduced to the point where the flame and air could enter the cylinder. You get the same effect with gas pipeline fires apparently, the flame face runs back down the pipe until you get a big bang and then it continues on its travels.

[Murflynn]

A container blowing from a pressure release valve is not the container failing, it is acting as it should, releasing the pressure to prevent an explosion.

 

So yes, nonsense.

Dear Lulu.

please advise your qualifications and experience that leads you to make such statements contradicting the widely held and generally accepted criteria of what comprises an explosion.

[Alan de Enfield]

Dear Lulu.

please advise your qualifications and experience that leads you to make such statements contradicting the widely held and generally accepted criteria of what comprises an explosion.

 

I think it is more a case of "I need to say something" (as my old dad used to say "empty vessels make the most noise") rather than any experience in the world of gas cylinder explosions.

 

In "the Pink" you might say.

[Murflynn]

You get the same effect with gas pipeline fires apparently, the flame face runs back down the pipe until you get a big bang and then it continues on its travels.

..... sometimes, in the case of catastrophic failure.

 

Another serious case (theoretically) is an oxygen pipeline where any hydrocarbon contaminants (think rubber or plastic) inside the pipe spontaneously ignite inside a sealed pipe, and the steel pipe then burns like a thermic lance, even below ground. I laid an oxygen pipeline in South Yorkshire and the risks of leaving foreign materials in the pipeline (and even using conventional pipeline cleaning 'pigs' with rubber seals which abrade and leave a deposit on the pipe wall) were drummed into us by BOC.

 

In typical pipeline fires, usually there is a small orifice (corrosion, flange gasket failure, point impact damage) producing a jet of flame (if ignited) which is best left well alone until the pressure in the pipeline has dissipated; air will not leak back because of pressure equalisation. I have witnessed this at the old BP Refinery on the Isle of Grain: one gas pipeline in a pipetrack (a channel dug below adjoining ground level) had a jet fire at a flanged joint, engulfing several other pipes carrying hydrocarbons where the coal tar coating caught fire. I noticed it and called it in. The refinery fire dept. came out in a mini pick-up and stood by, occasionally using an extinguisher to extinguish stop the coal tar fire. Eventually the jet fire ceased and the maintenance guys came out to look at re-sealing the joint. I can only conclude that it was a relatively common occurrence and a risk assessment had already established there was no risk in such cases. Makes you feel very uneasy nevertheless, when you are surrounded with high pressure vessels, oil and gas storage tanks and cylinders, and so on.

 

I think it is more a case of "I need to say something" (as my old dad used to say "empty vessels make the most noise") rather than any experience in the world of gas cylinder explosions.

 

In "the Pink" you might say.

.............. and my old dad always recalled the story of a bloke who wanted to braze his motorcycle tank. He warned him, the bloke told him to piss off; my dad complied and walked away swiftly ............... the rest is history.

Edited February 16, 2017 by Murflynn

[ditchcrawler]

..... sometimes, in the case of catastrophic failure.

 

Another serious case (theoretically) is an oxygen pipeline where any hydrocarbon contaminants (think rubber or plastic) inside the pipe spontaneously ignite inside a sealed pipe, and the steel pipe than burns like a thermic lance, even below ground. I laid an oxygen pipeline in South Yorkshire and the risks of leaving foreign materials in the pipeline (and even using conventional pipeline cleaning 'pigs' with rubber seals which abrade and leave a deposit on the pipe wall) were drummed into us by BOC.

 

Never worked with pure oxygen but know of the risk, I have seen pigs almost shredded and removed in bits by a second one.

[Alan de Enfield]

Never worked with pure oxygen but know of the risk, I have seen pigs almost shredded and removed in bits by a second one.

 

When flying in unpressurised aircraft above 16000 feet we required oxygen - when filling the oxygen bottles It was repeatedly drummed into us to ensure no oil or grease was on any of the pipes, connectors or threads.

Videos of 'what can happen' where horrific.

 

(A quick blast / breath of oxygen in the morning clears a headache better than any tablets)

[WotEver]

 

(A quick blast / breath of oxygen in the morning clears a headache better than any tablets)

A mate of mine (now sadly passed away) flew Corsairs and Hellcats in the Pacific Fleet. He often spoke of the above mentioned morning 'fix' for over-indulgence in the OM the previous night.

[IanM]

One Fire Brigade fire safety demonstration I watched involved putting a camping gaz canister on a fire... it definitely explodes!

[bizzard]

A bloke here once put a fridge on a bonfire, it went boom and jumped up in the air 6 feet.

[WotEver]

I tried lighting a bonfire with petrol once. It went 'whoomf!', jumped bodily about 4ft into the air and then settled back where it started.