Torch cutting

Steel is normally considered a safe material for contact with (reasonably pure) sulphuric acid. However this report is of a fatal explosion when working on a sulphuric acid tank with cutting torches, attributed to hydrogen in the headspace arising from corrosion of the metal ascribed to poor maintenance. 

Operations such as gas or electric welding and cutting with cutting torches cannot be safely performed on hydrogen gas pipelines, mains, or auxiliary equipment, unless all possibility of leakage of hydrogen into the work area is eliminated. The following procedures are recommended ... 

An oxygen-acetylene flame is hot enough to melt steel for welding. A cutting torch uses an extra jet of oxygen to bum away hot steel. 

Generally speaking, combustion is a heat-releasing chemical oxidation reaction, which is often accompanied by the occurrence of a flame. Flame temperatures differ widely from approx. 2000 K for an open flame to approx. 3000 K for the flame of an acetylene cutting torch. Remarkably, the heats of combustion of explosives is generally lower than those of common fuels (pine wood with 12.9% water 4.422 kcal/g, acetylene 11.923 kcal/g, dynamite 75% 1.290 kcal/g. 

Oxy-fuel burners were originally developed for applications that require extremely high flame temperatures that could not be achieved using air/f uel burners. Examples of these applicahons include cutting torches, glass polishing, and so on. Over the decades, advances in oxy-fuel burner... 

High-temperature cutting torches Reductive atmosphere for float-glass process Glass polishing... 

The task of cleaning up the crash site began about mid-day on Wednesday. By Eriday, the situation was felt to be well under control, security was relaxed, and people were allowed to return to their homes. Spectators and nonessential personnel were allowed into the immediate area of the derailment. Workmen smoked and used acetylene cutting torches at will in the process of cleaning up the site. A tank truck was brought in to offload the damaged propane tank cars. Friday afternoon, the... 

Oil gas syn. Pintsch gas is mostly methane with ethane, propane, butane, ethylene, and propylene made by exposing petroleum oils to high temperature. Although superseded in importance by natural gas, it is used in cutting torches to give a low temperature flame. 

Chlorine trifluoride seems to have been considered as an incendiary material in World War II by the Germans, who built a 1000-ton plant for its manufacture. A welding and cutting torch for copper using chlorine trifluoride and hydrogen has been described. ... 

As scale melts and runs off the steel surface, it exposes more virgin iron to the rapid oxidation (ablative melting). The exothermic heat release makes the reaction almost self-sustaining, similar to the reaction accomplished by a cutting torch. 

With burners that do not direct the combustion gases at the steel surface, the oxidation of the iron takes place without the velocity stimulant, so less oxygen contacts the hot surface. Without as much oxygen available, the reaction slows, and the exothermic heat of the reaction is not available to sustain the washing—similar to the effect of shutting off the oxygen to a cutting torch. 

Flammable liquids give off ignitable vapors. This, plus the fact that there are many ignition sources (such as a hand tool that sparks, or a cutting torch) at construction sites, is a real threat. Respect for, and proper use and care of flammable liquids is critical to a safe jobsite. 

Light and/or radiation hazards like optical radiation and poor vision. Sources include welding, cutting, torch brazing, torch soldering, lasers, ultraviolet infrared rays, and glare. 

Cutting, torch brazing, torch soldering Optical radiation Spectacles or welding face shield. Typical shades 1.5-3. See Notes 3 9. 

Use of a cutting torch where sparks will be a hazard is prohibited. 

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