Explosive ???? 3

[ietech]

In our shop a mechanic was observed igniting an oxy acetelene torch by striking an arc with the electric arc welder. This seems to me to be extremely risky business especially if the electrode comes in contact with the torch if it is in contact with the grounded welding bench during the ignition attempt.

Am I wrong? Does anyone have any info on the dangers of this. The supervisor thinks it is wrong too but doesn't take it very seriously. I think it could be a very explosive situation.

Thanks

 

[swall]

ietech--You've done a good job at identifying why it is a dangerous practice.

 

[StoneCold]

I have seen this done, and done it myself when that was the only source of fire I could get. I don't see any additional risk to lighting the torch with a striker, other than if you are not fairly quick you can end up with a lot of acetylene to burn off.
I would say that it is not very serious.
My opinion only.

Regards
StoneCold

 

[metengr]

For safety, please use a striker.

 

[swall]

There is also the risk of eye damage from UV if he does this long term. Presumably, the mechanic was going to be doing torch cutting and was wearing dark glasses appropriate for torch cutting,but which would not have provided protection from the UV from the arc.

 

[berkshire]

I would recommend that this be the topic of your shop's next safety meeting.
You do, have, safety meetings don't you?
B.E.

 

[kenvlach]

Cal/OSHA requires an Injury and Illness Prevention Program (IIPP) of every employer. If you ever have an accident investigated by Cal/OSHA, you better best be able to come up with signed & dated safety training for each employee. I also kept signed & dated attendence sheets of safety meetings, but don't remember if mandatory or a CYA precaution.

A sample IIPP for High Hazard Employers is at

http://www.dir.ca.gov/dosh/dosh_publications/iiphihzemp.pdf

Page 12 has a checklist for WELDING, CUTTING & BRAZING.
This specific hazard isn't listed, but would fall into several general categories for "appropriate operating instructions" and "only approved apparatus."

More Cal/OSHA publications are available at

http://www.dir.ca.gov/DOSH/puborder.asp

Cal/OSHA regulations are in Title 8 of the CCR (California Code of Regulations):
Welding & Flammable vapors are found in
Division 1. Department of Industrial Relations
Chapter 4. Division of Industrial Safety
Subchapter 4. Construction Safety Orders

http://www.dir.ca.gov/Title8/sub4.html

"Article 32. Oxygen, Acetylene, and Fuel Gas
§1740. Storage and Use of Cylinders.
...
(e) Cylinders must not be placed where they might form a part of any electric circuit." [doesn't mention a torch]

"Article 4. Dusts, Fumes, Mists, Vapors, and Gases
§1534. Flammable Vapors.
(a) Flammable vapors shall be controlled so as to avoid hazard to workers.

(b) No source of ignition such as smoking, gas pilot lights, or operating electrical equipment, other than explosion-proof or equivalent, shall be allowed in a room or building when hazardous concentrations of flammable vapors are present."

Lighting acetylene with an arc might be considered an (a) hazard or, if the arc melts a hole in the torch, hazardous concentrations of flammable vapors would be present pretty quick.

Requirements of appropriate eye protection as mentioned by swall can also be found.

 

[ietech]

Thanks to everyone for your response.

Berkshire - We do not have a special safety meeting just a daily shift change meeting which is probably the best venue available to address this. - thanks

Kenvlach - Thanks for the links, I searched CalOsha site but was unable to locate this issue. I am looking closely at the links you sent - thanks.

Swall - You bring up a good point about UVs - thanks

 

[unclesyd]

The welding burning goggle will provide some measure of protection, considerably more if the welder cocks his head.
I rarely see this with a pipe welder, its normally an iron worker or a fab shop welder that will light the fire in this manner. Sometimes the pipe welder will supply the fire for the fitter in this manner.

Another cute trick is to ask someone to light your torch and you turn on the gas prior to getting to the ignition source, usually a cigarette lighter.

http://www.eh.doe.gov/docs/osh_tr/ch5a.html

http://www.stoodyind.com/Catalogs/Commercial/pg537.pdf

Anecdotal:
A commercial fishing buddy of mine was a cutter/ burner in a local shipyard and while working on a work plank 40' off the ground he went to light his torch with a striker when he exploded. It blew off all his clothes and knocked him to ground. He suffered two broke hips and very bad burns. His torch was hanging from his clip on his hip and his coat was apparently forcing the gas into his pants. I asked him if he had smelled gas and he answered that there is always a gas smell around.

 

[kenvlach]

Here's an explicit prohibition in an OSHA-adopted national standard*:

"10.5.2.3 Lighting Torch. A friction lighter, stationary pilot flame, or other suitable source of ignition shall be used. Matches, cigarette lighters, or welding arcs, shall not be used for lighting torches.
Manufacturers procedures shall be followed with respect to the sequence of operations in lighting, adjusting, and extinguishing torch flames."

ANSI Z49.1:1999 Safety in Welding, Cutting, and Allied Processes,
A free download from the American Welding Society:

http://www.aws.org/technical/facts/Z49.1-1999-all.pdf

*American National Standards Institute standards are voluntary unless adopted by OSHA or other governing bodies. OSHA has adopted this standard (an earlier version, I don't know how it differs):
"29 CFR
Incorporation by reference. - 1910.6
...
1910.6(e)(62)
ANSI Z49.1-67 Safety in Welding and Cutting, IBR approved for §1910.252(c)(1)(iv)(A) and (B)."

Also, Canadian institutions participated in the writing of this standard, so perhaps it's also a legal standard in Canada.

 

[whizzz]

You can find about explosion caused by welding works here:

http://www.thefabricator.com/Safety/Safety_Article.cfm?ID=20

or

http://www.thefabricator.com/Safety/Safety_Article.cfm?ID=952

 

[ornerynorsk]

If you are lighting an oxygen lance, the preferred method is to use an arc welder. However, if this is an ordinary oxyfuel torch, for crying out loud, someone spend the $2 and get him a flint striker!!!