Man killed in explosion

[WebRam]

http://www.letchworthcomet.co.uk

A MAN was killed instantly and another injured in a violent gas explosion at a bakery in Stevenage town centre.
The blast ripped through Greggs bakery, in Town Square, just before lunchtime yesterday (Wednesday).
It was caused by a gas canister exploding while maintenance workers re-gassed a refrigeration unit at the rear of the shop at about 11.30am.
“It was very frightening, we thought it was a terrorist bomb at first,” said Niki Broughton, of King’s Walden Rise, Stevenage, who was working in offices on the floor directly above the bakery.
“It was just so loud. I thought somebody had crashed a lorry or something.”
Colleague Simon Ridout, 27, of Penn Way in Letchworth GC, said: “The whole building shook. I heard all this screaming, looked out the window and saw this poor lady and there were two guys there, one was telling all the people to get back and the other was comforting her.
“I have never seen anyone shaking so much and I think it was her that was screaming, ‘Oh my God, oh my God, oh my God,’ and looked like she had seen really bad stuff.
“I saw Niki and said we had better get out. I came downstairs and the bun racks were all on the floor.”
The damage did not extend to neighbouring premises, which were evacuated.
“It was like a gunshot or a bomb, really loud,” said eyewitness Barry Pick from his flower stall 30 metres away in the square.
“There was hardly anyone around in the square at the time and then more people started gathering round to have a look,” added Mr Pick.
“A man ran across the square and started getting everybody back. If it wasn’t for him everybody would still be flapping around.”
That man was shopper Barry Ellis, 46, from Letchworth GC, who said: “I ran across and tried to clear people away who were milling around. I could hear gas coming out from the cylinder so I didn’t go in. I just tried to get them out of the way.”
All five female staff escaped and were treated for shock at the scene, along with members of the public who were nearby.
Police took the workers into nearby Ladbrokes betting shop to take statements.
A force spokesperson said: “At this stage there is no reason to suspect any crime is involved. The man has not yet been identified or family informed.”
The victims were repair technicians for Essex firm D&P Catering Equipment. A company spokesperson said: “The Lister Hospital were excellent with our colleague who was injured and gave him a lot of time, as were the police.
“I am shaken up but it must be nothing compared to what he must be going through.
“I would also like to pass my condolences on to the dead man’s family at this sad time.”
As the clear-up operation began, investigators from the Health and Safety Executive and police scenes-of-crime officers assessed the site.
The body was removed from the bakery four hours later, and an inquest into the man’s death is expected to be opened and adjourned shortly.

[chemi-cool]

It will be more clear if we knew what really happened there.

What gas was he using? What caused the explosion?

Only when one gets all the facts, one can learn to avoid it.

God save his soul.

Chemi

[rdocwra]

Hi Guys,

My wife nearly had a heart attack when this can on the news because as per most days i was in stevenage that day.

This unfortunatly seems to becoming a more regular occurance. The last couple of times i have heard about it is when oxygen has mistakenly been used to presure test instead of OFN. I havn't really taken much notice but don't the bottles look the same, the only difference i think with the ones on my van are that the OFN's have a plastic webbing around them.

I sincerely hope that this wasn't the case again this time.

I know at this time there isn't anything that can be done for the family of this man and obviously my sympathys go out to them, i just hope that the cause can be found and positive action taken to stop this sort of thing happening to anyone else.


Regards

Raymond

[baker]

In Australia we have just had to go through the exercise of changing nitrogen regulators since new regulations mandate different bottle threads for O2, N2 and Air. Oxygen stayed the same, but air and nitrogen got new threads. Apparently this was due to an accident in a hospital where N2 was used instead of O2.

[Jasper]

Oxygen bottles are all black / OFN bottles are grey with a black top.

[chemi-cool]

Hi Jasper.

There you go. if the mixed bottles will stand together, all you see is black tops!!!!!

By us, oxygen bottles are green and round bottom. OFN and N2 are grey with square bottom.

I like the Australian way that threads are different. This is what we call: Fool proof.
Even if you get the bottles mixed you can not connect the wrong regulator.

This could save a few lives.

Chemi

[Argus]

We are all assuming that it was caused by Oxygen in the system.
Does anybody know?
It could equally have been any one of the other potential hazards in refrigeration.

We will not know the exact cause until the HSE finish and publish their investigations.

[mcamacho]

Hi!

With no facts, there is no information.

It is clear that different gases should be clearly identified with different colors and labels in their containers. But there is a thousand reasons why an explosion can happen: internal corrosion, by-passing safety devices during maintenance (mechanical or electrical/electronical), installation faults...

-Manuel.

[rdocwra]

Hi Guys,
I dont think that anyone is saying that this is the cause, however it had been well documented that this has happened in the past and in light of recent events maybe it's time to review the situation again.

it is a shame that the unfortunate events that happended in Stevenage a couple of weeks ago mean we all start looking at H & S again, surely this is something that needs no starting and should be ongoing


Regards

Raymond

[RogGoetsch]

Hi!

With no facts, there is no information.

When has that ever stopped us?!


It is clear that different gases should be clearly identified with different colors and labels in their containers. But there is a thousand reasons why an explosion can happen: internal corrosion, by-passing safety devices during maintenance (mechanical or electrical/electronical), installation faults...

-Manuel.

Good points. But actual explosions, as opposed to ruptures, for example, require a fuel and an oxidant mixed in a specific range of concentrations. And except with pure oxygen, they require a point of ignition. Just consider all the thousands of automobiles running into each other every day whose gas tanks don't explode.

For this reason, I would lean to the oxygen theory. Or could he have been working with a hydrocarbon R-12 replacement? I hope there is a follow-up on this story.

I once dropped a wrench which happened to hit the rupture disc of a full 30# R-22. It instantly blew out about half the charge and left the rest slowly boiling away as I calmed the staff and swallowed my embarassment!

Rog

[superheat]

Once we came back from lunch and the place we were working was shut down by the fire marshal. Come to find out a plumber cut off his O2 first then the fuel. He left a small flame on the torch and hung the torch over his tanks when he left for lunch. The acetylene tank blew up. nobody got hurt bad, but alot of people went to the hospital for shock. Everybody lost a 1/2 day of work. We went to the next job, but had to leave alot of tools there for the night. We might as well have gone home. Some job really suck if you don't have the right tools.

[Gwyn]

Only last Saturday whilst working in very confined plant room an engineer was brazing in a new oil sep. on the LT pack when only a couple of feet away from him the blow off valve decide that enough was enough blew off! to say the least he soon put out his torch a removed himself from the plant room!
H&S should be a key issue EVERY day you just never know…

.(A MAN was killed instantly and another injured in a violent gas explosion at a bakery in Stevenage town centre.) All my thoughts are with there family at this time.

[Blueboy]

Does any one no the actual cause of this terrible accident yet!!

[chemi-cool]

No but maybe you give Stevenage police a call and get the details for us?

Chemi

[chillyhamster]

Unconfirmed, but yes.

[Argus]

No but maybe you give Stevenage police a call and get the details for us?

Chemi

It doesn't work like that in the UK. Unless foul play is suspected, it is not a police matter at this stage.

In the UK, by law, serious injuries and fatalities in the work place are investigated by the Health and Safety Executive. They have statutory powers of investigation.

Their report and the Coroner's findings on the cause of the death will determine if there are any grounds for prosecution or not.

Until they complete their investigation there will be strictly no comment.

[mcamacho]

Hi!

ex·plo·sion ( P ) Pronunciation Key (k-splzhn)
n.

A release of mechanical, chemical, or nuclear energy in a sudden and often violent manner with the generation of high temperature and usually with the release of gases.
A violent bursting as a result of internal pressure.
The loud, sharp sound made as a result of either of these actions.
A sudden, often vehement outburst: an explosion of rage.
A sudden, great increase: a population explosion; the explosion of illegal drug use.
Linguistics. See plosion.

According to these definitions, an explosion does not require ignition or oxygen. It could be a release of mechanical energy, or a burst produced by internal pressure.

That is a little problem with the English language, as there is no "official" meaning of words as there is in other languages. You can look for "explosion" at dictionary.com and find other definitions that require sparks and oxygen.

Best regards,

-Manuel.

[Blueboy]

This is an Article that appeared in August's issue of the RAC magazine in the UK.

Engineer Killed in Bakery Blast.

The Health and Safety Executive (HSE) is conducting an investigation after a man was killed while working on refrigeration equipment at a bakery in Stevenage.
Details of the incident, which is believed to have occurred while the equipment was being pressure tested with Nitrogen, are yet to be released.
Local newspapers reported to explosion ripped through Greggs bakery in the town square, Stevenage while engineers were working on a refrigeration unit in the back of the shop. One man was killed in the incident and a second man was injured and taken to hospital.
Industry experts have been called in to aid the HSE in its investigation of the incident

A report of the findings will appear in a future issue of the RAC (Refrigeration and Air-Conditioning Magazine)

[chemi-cool]

Thanks Jules.

Chemi :)

[dunty]

hey guys,anyone looking for a young engineer to join their company,qualified and experienced in commercial/supermarket refrig..im just getting sick of waiting andagencies mucking me round
cheers justin
ps.im in london

[Brian_UK]

hey guys,anyone looking for a young engineer to join their company,qualified and experienced in commercial/supermarket refrig..im just getting sick of waiting andagencies mucking me round
cheers justin
ps.im in londonI'm not quite sure whether job hunting under the thread title of 'Man Killed...' is the best place to advertise :confused:

I suppose you could say that there is an opening but...well :eek:

[dunty]

brian,yeh i thought itd get some attention thats all.hehe

[Blueboy]

A little sick I think, after all a man died. If its attention your after there must be a less offensive way :mad: So if your looking for a job try the job database it's a little out of date but it's a better place than here!!!

[dunty]

cheer up blue boy,youve taken it the wrong way chief.the data base is very out of date and average

[RichB]

It is sad enough that someone has been killed without everyone jumping to completely unfounded conclusions. PLEASE can you WAIT and see what the HSE investigation reveals. I am as interested as anyone to know the cause.

Richard

[Coolie]

Oxygen bottles are all black / OFN bottles are grey with a black top.

This is only the case if you use BOC as your supplier.
The supplier we use have similar 02 and N2 cylinders. ie grey with a white or black top depending on which gas it is!

[Munzar Ata]

I think as we have learnt about this unfortunate mishap, we deserve to know full details of the actual investigation to ensure that such mishap does not recurr.

[thefridgedaddy]

which website was this story from?

[Argus]

The inquest on the tragic death in Stevenage last year is reported in various UK media.

http://news.bbc.co.uk/1/hi/england/beds/bucks/herts/4242264.stm

[chillin out]

Its a sad story, but I still cant understand why the comp blew before the other pipes.

I mean we all know how thin the evap pipes are and thats probebly where the leak was.

Just a thoght (1/4 inch steel against 1/32 inch copper????):confused:

[Argus]

What strikes me most is all the fuss about a "fridge too warm". Compare the caption with the picture

Journalists.

One other report I read, filed at about the same time as this one, stated that the late fitter used Hydrogen to pressurise the system.

Even though the jury returned a verdict of accidental death, it is probable that the HSE will pursue the matter if there is an element of culpability.

The findings of their enquiries are seldom made public, so we may never know.

.

[Tycho]

Just happened across this one...

Still no conclusion?


Luckily, in Norway, we have different fittings on O2 and N2 bottles... O2 has internal threads and N2 has external threads. a year ago, O2 bottles were a sky blue color and N2 bottles were grass green, but not it has changed, so N2 bottles are grey with black on the top curve towards the valve., not sure what color the new O2 bottles are, as we still have two of the sky blue in stock.


It might be as simple as a defective N2 regulator, I got the scare of my life myself once with one.
I was pressure testing a compressor unit with a bitzer semi hermetic screwcompressor and an oilcooler.
I wasnt strength testing any welds, so I charged the unit with 22bar (4 bar over the sfv release pressure).

I had allready checked all the connections and flanges at 0.5 and 10 bar with no leaks, so I descided to leave it at 22 bar while I tended to some other things.

I just loosened the regulating screw on the regulator, and didnt bother to close the bottle valve.

five minutes later I heard "eeeeeeeeeeee" from the compressor room, so I headed on over to check it out, halfway there it went from "eeeeeeeeee" to "eeeeee*POW*SSSSSSSSSSSH" :D nothing like sound effects eh? :), I'm running now towards the door, stop at the N" bottle that is outside the room and see that I have 50 bar on the compressor... I close the bottle and go back to the PM valve I was working on.

when the "EEEE" sound stops, I go back and notice that the gasket on the thrust bearing side of the compressor has been blown out, but there is still 20 bar left on the unit.

I close the valve on the unit and start unscrewing the hose (we use 10mm ermeto fittings), I'm holding the hose with my left hand as I'm loosening the nut with the wrench in my right hand. when the nut moves freely, I give it the obligatory tap with the wrench to make the fitting let go while the nut still has threads left (so as not get a runaway hose :))

sadly, the hose tore free from the fitting, the 50 cm between my left hand and the valve whipped upwards as 15 meters of hose let go of 20 bar, and me and the hose performed a pretty good performance of lady and the tramp (where the spaghetti whiplashes up the face), what was left of the fitting smacked me pretty good on top of the head... the stars, pain and the bang when it let go left me with a great deal of respect when it comes to pressure...


so there, you got a story to go with my request :)

[TSK]

I need to check this out but maybe someone has already, when recovering R410a into a cylinder using a standard recovery unit the pressure I have been told can get very high +30bar, is this not higher than the test pressure for the cylinders?

[Tycho]

I need to check this out but maybe someone has already, when recovering R410a into a cylinder using a standard recovery unit the pressure I have been told can get very high +30bar, is this not higher than the test pressure for the cylinders?

We pressure test large industrial plants with +30 bar.

besides, cylinders have safety valves, or burst disks fitted.

plus a recovery unit should have a HP cut out way below the burst pressure of a cylinder (could have been disabled tho)

[Pooh]

I may have misread the report from the BBC but it appears that the guy was not using a regulator but was coming straight of the bottle. I have been told by apprentices that this is done by engineers who have not been supplied with replacement regulators when theirs are damaged so the engineer removes the adapter and braises on a 1/4 connector. I have also been told that certain engineers cant be bothered to fetch the nitrogen from the van so they use oxygen. This frightens me senseless and makes me wonder how more dreadfull articles like this we are going to have to read.

Ian

[Andy]

Hi pooh:)

I caught one of the commercial refrig apprentices with a bit of copper pipe welded to a nitro bottle fitting. I asked him what he was at and where he got the fitting, he told me one of the senior engineers gave it to him.:confused:
We bought all the guys regulators after that and I had it out with the senior guy who gave this to a first year:mad:
I look after the industrial side of the business, we all had our own regulators before that happened, but it just shows what could happen if companies don't supply the correct gear.
The commercial guy with the 1/4 pipe and fitting now works for a different company, he was just too much trouble to manage and had no health and safety in him.
:)

Kind Regards Andy

[Tycho]

I may have misread the report from the BBC but it appears that the guy was not using a regulator but was coming straight of the bottle. I have been told by apprentices that this is done by engineers who have not been supplied with replacement regulators when theirs are damaged so the engineer removes the adapter and braises on a 1/4 connector. I have also been told that certain engineers cant be bothered to fetch the nitrogen from the van so they use oxygen. This frightens me senseless and makes me wonder how more dreadfull articles like this we are going to have to read.

Ian

Holy crap, none of that would have even remotely occured to me, and if it had, I would have laughed at myself for even thinking of something so stupid...

[US Iceman]

I have also been told that certain engineers cant be bothered to fetch the nitrogen from the van so they use oxygen.


This has some suspicous qualities about it Pooh. I will be the first to admit I do not understand the chemical reaction that takes place when oil and oxygen are combined, other than to say it has the making of an immenient explosion. Most of us have heard something similar to this.

Having said that, I would have to take any comment saying oxygen was used to pressurize a system "with a grain of salt".

There may have been some unknown factor(s) which luckily prevented an explosion form taking place, if this did occur.

I'm not sure what "that" might have been, but, another possibility could have been the person who told you this did not know the difference between a nitrogen tank and an oxygen tank.

I've heard some comparable comments like this that just scare me to death and hesitate to repeat them for fear of someone reading/hearing those comments and saying, "if they can do it, I can do it".

Unfortunately, those that do not know the dangers of working on refrigeration systems and insist on doing it anyway (or without ADULT supervision:rolleyes:) often find themselves in a precarious situation that if they are lucky, they can walk away from it.

I recently had the opportunity to correspond with a gentleman about a similar project in South Africa. Peter_1 is familiar with it.

A technician (and I use the term loosely) was trying to find a restriction in a split system after a "leak repair". The compressor exploded right in front of him. He was extremely lucky and survived.

I won't give away all of the details as the story should be coming to print early next year as a warning of this sort of untrained work methods and poor service practices.

[LRAC]

May be as part of their trainning engineers should attend brazing courses using oxy/acetelene instead of using those cheap micro flame rigs or the hand held Mapp gas cylinders.

At all times using oxy/acet you are taught about cleanliness of the oxy regulator and cylinder care along with "for god sake keep the oxy regulator shut near oil".

Once again it points to lack of trainning and people prosumeing and we know what presumption is " its the mother of all **** ups".

Lrac

[US Iceman]

May be as part of their trainning engineers should attend brazing courses using oxy/acetelene instead of using those cheap micro flame rigs or the hand held Mapp gas cylinders.


That's a good point. A similar analogy is that people learning to drive should learn on a manual transmission first so they understand how to do it. They don't have to drive a manual shift, but they should certainly understand how to.

The same applies to the use of oxygen/acetylene rigs.

PS. I even seem to remember a warning on the oxygen regulators about preventing contact with oil. The regulator set I used to have, had this printed inside the regulator face, under the glass lens.

[Pooh]

With reference to brazing we now teach all the apprentices that attend our department to CITB/BRA standards and issue them with certificates, as part of the assessment they have to complete an examination and I know for definate that at least one of the questions covers oil and oxygen and others on other oxy acet safety. As far as brazing with map gas I will not let it be used in the department as it does not heat the pipe quickly enough and thus causes more damage to the pipe work and if used without nitrogen purging creates far more oxide inside the pipework and more damage to the system especially the compressor. It is my opinion that the use of map gas is purely a case of laziness on the part of the operator or an unwillingness of the company to buy the correct equipment.

Ian

[steveg]

I work for the company who manufactured the refrigerated cabinet. We have carried out a full investigation into what exactly happened, these are the facts.

1. The gas was OFN
2. The regulator was broken and allowing full bottle pressure into the compressor body
3. This was not a hydrocarbon cabinet
4. The compressor body ruptured as full bottle pressure was allowed into the system
5. The compressor body ruptured as the engineer leaned over the system

The cause for the compressor body rupture was put down to a massive pressure shock that was introduced into the system by a faulty regulator. The copper components had shown signs of expansion but due to the flexibility of the copper and the inflexibility of 3mm plate steel (compressor body) the result was the head of the compressor parting with the compressor.

[Tycho]

I work for the company who manufactured the refrigerated cabinet. We have carried out a full investigation into what exactly happened, these are the facts.

1. The gas was OFN
2. The regulator was broken and allowing full bottle pressure into the compressor body
3. This was not a hydrocarbon cabinet
4. The compressor body ruptured as full bottle pressure was allowed into the system
5. The compressor body ruptured as the engineer leaned over the system

The cause for the compressor body rupture was put down to a massive pressure shock that was introduced into the system by a faulty regulator. The copper components had shown signs of expansion but due to the flexibility of the copper and the inflexibility of 3mm plate steel (compressor body) the result was the head of the compressor parting with the compressor.




Thanks for the update mate.

after my little scare I always stay by the regulator till I have the pressure I want, then I close the main valve on the bottle.

[US Iceman]

I do not remember reading anything about the type of regulator used, so I thought I would post some information that might be worthwhile.

http://www.airproducts.com/nr/rdonlyres/7f99fa03-0f07-49b6-a7fe-655196229ad7/0/safetygram12.pdf

http://www.airproducts.com/nr/rdonlyres/8d35ea4f-b95f-42c6-9087-6125c1f4123a/0/safetygram10.pdf

http://www.airproducts.com/nr/rdonlyres/e0cc131e-345a-4c39-aade-a42205531ee1/0/safetygram31.pdf

Here is some pretty good basic information on safety...
http://www.phy.cam.ac.uk/cavendish/hands/cops/gasescop.pdf

[chillerman2006]

:( the way i here this dreadfull accident happened is =

an engineer and a apprentice were working on a chilled display counter in gregs

the unit had a gas leak which the engineer had traced to on or around the area of the compressor. this had been done using ofn but the bottle being used was nearly empty so the engineer wound the regulator in fully to extract the last of the nitrogen from the bottle.

the top of the compressor was rusty and was probaly the cause of the leak.

the engineer then asked the apprentice to fetch the full bottle from the van and swap the regulator over.

this he did but he left the regulator fully wound in and this particular regulator being used for some unknown reason was capable of over 100bar

the engineer could here a hissing coming from the top of the top of compressor which is where his head was

at this point the apprentice opened the bottle allowing over 100bar into the system - the leak from ontop of the rusty compressor created a weak spot which caused the top of the compressor to blow straight off

the coroners report has returned a verdict of accidental death but the hse want some questions answered

1. why was such a large regulator issued to the engineer in the first place

2. who made this decision

3. what training had the engineer and apprentice recieved in leak or strength testing eqipment

obviously by these questions being asked the hse are looking to blame someone and probaly make criminal charges to either the company, senior staff or both.

the outcome of the hse's investigation is due this week

[craigpcg]

this happened to a certain company up here in scotland where a-gas wrongly marked up a bottle ofn when it was oxygen,engineer pressure tested let the gas out but when he went to repair leak with blow torch well i think u can guess what happened. the bugger got 300,000 in damages.

[The MG Pony]

was there any thing left of the poor basterd to enjoy that money n time off to heal though!

[craigpcg]

well there was a bit of a skin graph done but apart from that not much else lol.

the shop was a total write off tho

[The MG Pony]

dam lucky guy!