Welding Tips and Tricks

All the tips you guys have for set-up, shut-down, heating, welding, and cutting

http://www.weldingtipsandtricks.com/cut ... -tips.html

Thanks,

John

I'll have to take a look at that later, when I'm caught up.

I have yet to see anything on O/A I consider "complete". I have OSHA and MSHA training, and they are not complete. There are some DOT regs that the other alphabets don't cover, and some Mfg. recommendations that few seem to pay attention to.

Jody is the most likely person I know to cover it all well, and I'll have a look at the link this evening.

Steve S

I'm looking for some tips on torches, experience any of us have had over the years,
any thing related to Oxygen and Acetylene.
I know lots of Guys( and Gals) who I'm sure need to learn a lot on cutting torches....
So any help you can give to people seeing this...
I'm sure will be appriciated....

John

lets make this a "sticky" thread...
John

Google this topic. You'll find a boat load of old and new information that's been beat to death about it already. Maybe this is why nobody has really replied to the topic with much fanfare.

I know you can lay an oxygen bottle on its side, resting in a 2" x 8" x 8' "V" chute, on the third floor at Fisher Island, knock the tap off with a sledge and that sucker will fly out into Biscayne bay.
Hey. We were bored and the guy who owned the tanks(all four) was a prick.

Actually our next safety meeting will cover torch safety/how to use. I have engineers that come out in to the shop from time to time and will help out. One thing I have noticed it a lack of torch knowledge from them ( I know, I know that is not their forte). For example I noticed not knowing how to light a torch and once, one torching in the direction of their tanks. We are actually going to use the video John put up in the meeting. I feel it covers a lot and is not boring like some videos can be.
I also agree, most has been covered about torch safety but while talking to another weldor we realized how easy it is to forget the little things. Repetition is the best teacher.

I tried to post a detailed story on here but i closed the browser before posting. Dammit.

Long story shortish, We use oxy/propane w/ rosebud tips for preheating, the torches are equipped with dead man switch/solenoid to prevent leak/in inadvertent turning on in confined spaces.

However SOME people are relying on the switch to turn the gas on and off instead of the taps. This result is mixed gasses of a highly explosive ratio come out as soon as you hit the button. We havent had an accident yet but i have a feeling they will be a peeling someone of the ceiling in the future, (Sorry)

Mick

If you ever lay a acetylene bottle down you need to sit it upright for about 30 mins before you use it, very important! Also make sure you have the proper gauages on the set-up so can set the pressures correct. Never over 15psi on Acetylene, I use 6psi and 6psi to Oxy weld but Ill be honest very rare for me to Oxy weld any more

Never ever ever put a tank of any kind across the forks of a lift. If it ever got hit or rolled off bang the explosion would take an entire building out.

Saw a guy dong that in a huge warehouse we were renovating. Guys could hear me yelling at me from the other side of the building.

When i was a bit younger i worked at a LWS and got pretty familiar with some part numbers like a CGA 540 and a CGA 510. These are the fittings that attach to oxygen and acetylene cylinders. The numbers only tell you what gas they are threaded for but what does the CGA stand for? Compressed Gas Association! They have plenty of valuable info on the safe use of any CGA cylinder.

Hey,

I saw a youtube video of a port crane demolition here in Aus, the first thing that happens is that a forklift driver drops a BANK of 9 oxy bottles seems to have absolutely no regard for how dangerous they are. Complete fool. Unfortunetly, the whole project seemed to have been run by FIs because very soon after that , the cutting crew cuts too many connections in preparation for explosive demolition and the whole stucture collapses, killing at least 3 workers .

Mick

Yes - that was a professional job alright - what is the Australian term for " Redneck " ? ! it did look nasty - I never read how many were hurt ( sorry to hear of the 3 fatalities ) - watching it I did'nt think they were preparing to finish the cutting explosively - it appeared they knew it was close to collapse & believed they could move away in time.

Slightly off topic there is a similar crane on you tube on a dock where a ship manages to drag it a short distance on it's tracks before toppling it sideways - not sure where it was - but the excited chatter in the background was not English !

Not really sure of the number but there were a number of guys around and in the EWP when she fell. Just a shamozzle from the get go, unfortunately. You tube is full of crazy videos like that.

Arizona SA200 wrote:When i was a bit younger i worked at a LWS and got pretty familiar with some part numbers like a CGA 540 and a CGA 510. These are the fittings that attach to oxygen and acetylene cylinders. The numbers only tell you what gas they are threaded for but what does the CGA stand for? Compressed Gas Association! They have plenty of valuable info on the safe use of any CGA cylinder.

CGA holds the standards for much larger fittings...

NIT300, OXY250, AR150, as examples... However, these are not used for gas. They're for liquified gasses.

Just an interesting "aside".

Steve S

Its always sad to see an accident that would have been prevented if someone said wait this doesn't look or feel safe. A company pulling crap like that here in Ontario would be bankrupt from law suites and fines for negligence. Plus the owners and supervisors would have been personally fined big time.

c2h2 decomposition heard anything about it?

braderfitter wrote:c2h2 decomposition heard anything about it?

Yep. That's why acetylene gauges have a red line above 15 PSI.

Here's a quote from the Wikipedia article:

"Acetylene is not especially toxic but when generated from calcium carbide it can contain toxic impurities such as traces of phosphine and arsine. It is also highly flammable (hence its use in welding). Its singular hazard is associated with its intrinsic instability, especially when it is pressurized. Samples of concentrated or pure acetylene can easily react in an addition-type reaction to form a number of products, typically benzene and/or vinylacetylene. These reactions are exothermic, and unlike other common flammables, do not require oxygen to proceed. Consequently, acetylene can explode with extreme violence if the absolute pressure of the gas exceeds about 200 kPa (29 psi). Most regulators and pressure gauges on equipment report gauge pressure and the safe limit for acetylene therefore is 101 kPagage or 15 psig.[27][28] It is therefore shipped and stored dissolved in acetone or dimethylformamide (DMF),[29] contained in a gas cylinder with a porous filling (Agamassan), which renders it safe to transport and use, given proper handling. Copper catalyses the decomposition of acetylene and as a result acetylene should not be transported in copper pipes. Brass pipe fittings should also be avoided."

Complete article found here:

http://en.wikipedia.org/wiki/Acetylene

Steve S

I've always been wary of acetylene - the pressure limit is why we could'nt use it underwater but I have a mate that used to decant it with a hose at cylinder pressure into small cylinders for hobbyists / roofers - because it never exploded he did'nt believe my warnings mostly because like he said BOC must have done it to get it in the bottle - I had no answer to that at the time - they did subsequently blow both their bottling plants up though ! - What I have'nt seen in years is a small acetylene generator - these were quite common & often sold for hobby use in classified ads - I still have a 40 gallon barrel full of carbide crystals which would last me a long time if I could use them - only thing they get used for is killing sea gulls or blowing up rats !

Otto Nobedder wrote:

braderfitter wrote:c2h2 decomposition heard anything about it?

Yep. That's why acetylene gauges have a red line above 15 PSI.

Here's a quote from the Wikipedia article:

"Acetylene is not especially toxic but when generated from calcium carbide it can contain toxic impurities such as traces of phosphine and arsine. It is also highly flammable (hence its use in welding). Its singular hazard is associated with its intrinsic instability, especially when it is pressurized. Samples of concentrated or pure acetylene can easily react in an addition-type reaction to form a number of products, typically benzene and/or vinylacetylene. These reactions are exothermic, and unlike other common flammables, do not require oxygen to proceed. Consequently, acetylene can explode with extreme violence if the absolute pressure of the gas exceeds about 200 kPa (29 psi). Most regulators and pressure gauges on equipment report gauge pressure and the safe limit for acetylene therefore is 101 kPagage or 15 psig.[27][28] It is therefore shipped and stored dissolved in acetone or dimethylformamide (DMF),[29] contained in a gas cylinder with a porous filling (Agamassan), which renders it safe to transport and use, given proper handling. Copper catalyses the decomposition of acetylene and as a result acetylene should not be transported in copper pipes. Brass pipe fittings should also be avoided."

Complete article found here:

http://en.wikipedia.org/wiki/Acetylene

Steve S

Thanks Steve. I never knew that the copper is a catalyst for decomposition

I do have to wonder, now, since my Victor torch seems to be mostly yellow brass, including the flashback arrestors. Perhaps red brass is the greater hazard?

I may have to take a closer look at the copper/catalyst idea.

Steve S

Hey, thats what i thought....every oxy torch ive ever seen has been brass....

Mick

i have a question, if decomposition do occur can it be prevented or contained by flashback arrestor and non return fittings from reaching the bottles?
Our gas welding system here on board is a centralize distribution system. The hoses fitting are non return connected to flashback arrestor which is connected to low pressure regulator, the comes the long distribution ss pipe with 8 bar and 0.8 bar for oxy and ace respectively it goes all the way to separate oxy acetylene bottle room . The pipes are connected again to another flashback arrestor prior to high pressure regulator. High pressure line is fitted with individual pass thru valves for each bottle and non return fittings,and finally the high pressure hoses connected to the bottles are steel reinforced. The bottle room is located outside the the ship so if everything goes wrong we could jettison those bottle into the sea.
the copper catalyst idea somehow made me worry just a little since my gas welding equipments here are all made of brass and specially the cutting nozzles are all red brass. i am sure it is not pure copper. And if you are in the middle of the ocean you don't want that decomposition thing happen onboard.

This has had me curious as well. I will do some research and ask around, my first response would be Victor, Smith an other manufactures would not and could not manufacture a torch or other devises that would potentially be able to harm or break down the acetylene. However if the case is that they can in fact break it down my other guesses would be first the flow of the acetylene does not allow any beak down and second if one is following proper torch safety rules, you would not have gas in your lines overnight/very long anyways thus not allowing the acetylene time to break down.
-Jonathan