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Carl.Riva  
#1 Posted : 17 July 2019 12:19:12(UTC)
Rank: New forum user
Carl.Riva

I have been asked to commission the welding training workshop. it contains 10 bays with metal pipes supplying each bay with oxygen, acetylene and argon. it occurred that each bay then be able to carry out either MIG or Oxy Acetylene welding, not at the same time though. Is having this configuration practical or should i remove Oxy Acetylene from a number of bays, sort of divide them?

I have been looking at regulations but can't seem to find anything in black and white. 

Thank you for your help

JohnW  
#2 Posted : 17 July 2019 15:28:00(UTC)
Rank: Super forum user
JohnW

Pipes for welding gases..... I have never seen such an arrangement, but I'm not a welder - I have only observed the welding equipment at numerous metal fabricators. In all cases each welder/bay has his own dedicated gas cylnders on a trolley or chained to a wall.

I suggest posting on a Welders Forum e.g. 

http://www.ukwelder.com/forum/lofiversion/index.php/forum/

Edited by user 17 July 2019 15:28:51(UTC)  | Reason: typos

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Carl.Riva on 15/11/2019(UTC)
stevedm  
#3 Posted : 18 July 2019 06:55:00(UTC)
Rank: Super forum user
stevedm

You should really be looking at the BCGA for some help as well as general advice from the forums..http://www.bcga.co.uk/pages/index.cfm?page_id=112&title=guidance_notes_

The guidance and technical notes will help guide you to the standards.

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Carl.Riva on 15/11/2019(UTC)
paul.skyrme  
#4 Posted : 18 July 2019 08:44:21(UTC)
Rank: Super forum user
paul.skyrme

The pipework is just a result of using bulk supply manifolded cylinders, or generation plant.  More economical for high volume use.

When I trained we had segregation, because of the screening requirement around arc welding to protect bystanders from the arc flash, coupled with different bench heights to reflect the different welding styles required when standing.

If all is correctly installed and maintained, with suitable and sufficient supervision of the trainees so thay there is no horse play then all should be fine.

We did not have bulk supplies, and for training, I do not think it is a good idea.

If you have local cylinders you can use these to train on cylinder safety, handling, change over etc.  Plus it gives the trainees some incentive to make sure that they make the cylinder/hose connections correctly when they realise that if they do it wrong, and the cylinder blows up, (which is very unlikely) then they are the first in the firing line.

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A Kurdziel on 19/07/2019(UTC), Carl.Riva on 15/11/2019(UTC)
chris42  
#5 Posted : 19 July 2019 08:55:13(UTC)
Rank: Super forum user
chris42

We don’t know exactly what your set up is, but my concern would be that If the oxygen/acetylene hoses are close to the MIG welding, then stray spatter could damage the hoses. However, provided they can be put up out of the way when doing MIG then I don’t see an issue.

Please try specialist sites as others suggest, you never know what may be said and spark a thought for you, but I suspect your question is too specialised around this issue and training. Therefore, you will get other opinions (and possibly food for thought which is sometimes a good thing). Ultimately look at you set up and decide what could go wrong. I have given an example above of something I would consider. It does make practical sense to have the bays dual purpose.

I agree with Paul's comments about bulk piped supplies being for high volume work (more industrial use). However, I have noted that Fire people and even the fire brigade in the past preferred these things outside and piped, opposed to inside a building. All the people we have ever had do a Fire Risk assessment get twitchy over the use of Oxygen / Acetylene kits full stop. However, if they are handled properly the is no reason to.

Chris

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Carl.Riva on 15/11/2019(UTC)
paul.skyrme  
#6 Posted : 19 July 2019 13:41:30(UTC)
Rank: Super forum user
paul.skyrme

Not sure if anyone is aware, but the guidance around acetylene has changed recently, it has been relaxed somewhat.

Now I'm not sure exactly who did the research, ore xactly where to find it now, but I have read it.

Good CPD for those it's relevent to to track it down and read it perhaps! ;)

There were experiments done, I think in mainland Europe as it was the only suitable facility, I seem to recall the HSE & the Chief Fire Officers Association were involed.

The research was basically to put an aceytlene cylinder in a fire and try and blow it up.

They failed!

I think it was brought about to reduce the fire service response to fires invovling acetylene where large exclusion zones were required and long cool down times with hoses after the fact.

Sorry I can't recall all the detail, but the report is out there somewhere in the public domain,

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Carl.Riva on 15/11/2019(UTC)
Spacedinvader  
#7 Posted : 19 July 2019 13:54:54(UTC)
Rank: Forum user
Spacedinvader

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Carl.Riva on 15/11/2019(UTC)
johnmurray  
#8 Posted : 23 July 2019 11:38:15(UTC)
Rank: Super forum user
johnmurray

Originally Posted by: paul.skyrme Go to Quoted Post
Not sure if anyone is aware, but the guidance around acetylene has changed recently, it has been relaxed somewhat.Now I'm not sure exactly who did the research, ore xactly where to find it now, but I have read it. Good CPD for those it's relevent to to track it down and read it perhaps! ;)There were experiments done, I think in mainland Europe as it was the only suitable facility, I seem to recall the HSE & the Chief Fire Officers Association were involed.The research was basically to put an aceytlene cylinder in a fire and try and blow it up.They failed!I think it was brought about to reduce the fire service response to fires invovling acetylene where large exclusion zones were required and long cool down times with hoses after the fact.Sorry I can't recall all the detail, but the report is out there somewhere in the public domain,
Hold an Acetylene cylinder, using appropriate manual-handling procedures lay it flat on the ground. Look inside the concave bottom of the cylinder. You will see a "plug". It is made of a metal with a low melting point. For obvious reasons. Return the cylinder to an upright position, wait the appropriate time for contents to settle before using.
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Carl.Riva on 15/11/2019(UTC)
johnmurray  
#9 Posted : 23 July 2019 11:42:10(UTC)
Rank: Super forum user
johnmurray

I'd like to inform you of a precaution to take....make sure the piping is vertically installed. Otherwise you may find them used as convenient hangers for things like MMA welding torches.....live torches...
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Carl.Riva on 15/11/2019(UTC)
Carl.Riva  
#10 Posted : 15 November 2019 14:05:26(UTC)
Rank: New forum user
Carl.Riva

Thank you all for your responses. In the end, the department manager has now removed all acetylene from the site. So that removed that problem. 

I spoke to many providers, one helped me massively. In a nutshell, there was nothing wrong with the setup. The system had all the correct flame arrestors installed and I changed the working process i.e. placement of hoses when not in use and so on.

The firefighters did an inspection and they were happy with the setup. Note about acetylene, if the cylinder is exposed to a heat flash i.e. fire. The firefighters will put in a 200m cordon and spray with water for 4 hours. Acetylene, once heated will go into exothermic reaction, the gas inside can become unstable and still generate heat. Sadly a firefighter lost their life removing cylinders once exposed to fire, why they will never go near them now (UK).

Again thank you all for your advice, very helpful. 

andrewcl  
#11 Posted : 19 December 2019 15:48:00(UTC)
Rank: Forum user
andrewcl

Yeah, I know, I bumped the thread...

First off, paul.skyrme is correct - the research was done at the BAM facility in Germany and was "sponsored" (if that's the right word) by Transport for London, HSE and a couple of others.  The belief was that an acetylene cylinder required cooloing water sprayed onto it for 24 hours, after it had been involved in a fire.

The research was initiated after one particular year in London saw something like (happy to be corrected...) 42 incidents involving acetylene, which probably caused many hold ups in a city that busy.

As has been stated by Carl.Riva in the last post, acetylene is unstable (cylinders are filled with acetone, which keeps acetylene from spontaneously decomposing) and when it does split, it emits heat, which destabilises surrounding acetylene molecules causing them to also split.  This leads to a chain reaction scenario, leading to pressure building up in the cylinder.

Also correctly stated, a fire man died (in Hampshire, IIRC, in 2008) while moving an acetylene cylinder that had been involved in a fire and which had this chain reaction happening inside it.

The BAM research concluded that 15 minutes of cooling was sufficient (leaving the cylinder in situ), but recommended 1 hour to be on the safe side, with 1 hour of monitoring.

Acetylene cylinders (and pretty well most cylinders with liquids inside) have a pressure relief valve on them somewhere because if all the liquid turned into a gas, you'd have a fair bit of pressure to contain.

Previously mentioned is the BCGA website, with their (at the time of press) free to download guidance notes and codes of practice, which give examplary advice on the use of gases.

chris42  
#12 Posted : 19 December 2019 16:08:00(UTC)
Rank: Super forum user
chris42

chris42  
#13 Posted : 19 December 2019 16:27:38(UTC)
Rank: Super forum user
chris42

Sorry should have added, the referenced document is in two parts and gases start at page 300 in the 1st part but then you need to go to the second part. From page 316 onwards it is about acetylene and the operational guidance is on page 324 and flow chart on page 325.

Everything you ever wanted to know, knock yourself out.

Our previous Fire risk assessor ( I was in the brigade type) would not believe the attached when I said what he had in the RA was not quite right ( 200m for 24 hours). Ho Hum so much for bringing so called experts in.

Chris

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