Acetylene welding

Ethyne is the starting point for the manufacture of a wide range of chemicals, amongst which the most important are acrylonitrile, vinyl chloride, vinyl acetate, ethanal, ethanoic acid, tri- and perchloro-ethylene, neoprene and polyvinyl alcohol. Processes such as vinylation, ethinylation, carbonylation, oligomerization and Reppe processes offer the possibility of producing various organic chemicals cheaply. Used in oxy-acetylene welding. 

Oxygen enrichment of steel blast furnaces accounts for the greatest use of the gas. Large quantities are also used in making synthesis gas for ammonia and methanol, ethylene oxide, and for oxy-acetylene welding. 

A high-pressure air compressor drew its air from an area where oxy-acetylene welding was taking place. Small amounts of copper acetylide formed on a bronze valve and exploded. 

An alkyne is a hydrocarbon that contains a carbon-carbon triple bond. Acetylene.. H—C= C—H, the simplest alkyne, was once widely used in industry as the starting material for the preparation of acetaldehyde, acetic acid, vinyl chloride, and other high-volume chemicals, but more efficient routes to these substances using ethylene as starting material are now available. Acetylene is still used in the preparation of acrylic polymers but is probably best known as the gas burned in high-temperature oxy-acetylene welding torches. 

Of great practical interest is also trimethylborate it is used as raw stock for the synthesis of various boron compounds (sodium and potassium bo-ranes, trimethoxyboroxol, etc.) and as a flux for acetylene welding of metals. We should also note the possibility of using lower trialkylborates in the distillation of alcohols, and of triethanolamineborate as a catalyst for the solidification of epoxy polymers. 

Acetylene itself has considerable value (equivalent to ethylene) for producing a variety of specialist chemicals as well as the commodity monomer vinyl chloride (by addition of hydrogen chloride) and its use as a specialist fuel - acetylene welding. Acetylene is very dangerous in the liquid state, and is not distilled. In the pure form it has a tendency to explosively decompose ... 

A graduate student in Hideki Shirakawa s laboratory at the Tokyo Institute of Technology was trying to make a polymer called polyacetylene from ordinary acetylene welding gas. The polymer, a dark powder, had first been synthesized in 1955, but no one knew much about it. Instead of a dark powder, Shirakawa s student produced a lustrous, silvery film that looked like aluminum foil but stretched like Saran wrap. Looking back over his chemical recipe, the student saw his... 

Electrical insulator inspection and casing testing Oxygen/acetylene welding Locating and marking pipelines... 

Gas welding is usually known as oxy-acetylene welding, after the gases commonly used in the welding process, oxygen and acetylene. 

Oxy-acetylene welding uses the combustion of the two gases, oxygen and acetylene, to create a source of intense heat, providing a flame temperature of around 3000/3200 C. This heat is sufficient to melt the surface of the metals being joined, which run together and fuse to provide the weld. Additional material in the form of a filler rod may sometimes be required. 

The oxy-acetylene welding process can be applied in steels up to and exceeding 25 mm thick, but is mainly used on gauges up to 16 SWG (1.6mm), where the heat input needs to be flexible, and for welding die castings and brazing aluminium where the heat must be maintained within a critical range. 

During oxy-acetylene welding it is the flame which does the work and is therefore most important. The welding equipment already described merely serves to maintain and control the flame. It is the operator who sets the controls to produce a flame of the proper size, shape and condition to operate with maximum efficiency to suit the particular conditions. 

Are oxygen and acetylene welding tanks equipped with shut-off valves Yes No N/A... 

Acetylene-burning Acetylene-cutting Acetylene-welding Chemical handling Chipping... 

The oxy-acetylene welding process can be applied in steels up to and exceeding 25 mm thick, but is... 

Meanwhile, a very important, new use for acetylene had been developed, oxy-acetylene welding and cutting. The oxy-acetylene became popular because it gave a temperature of 6,000 to 7,000° F. contrasted with 4,000, the maximum attainable with the oxy-hydrogen flame. This application stimulated the invention of a safe method of compression acetylene to facilitate its storage and shipment. The challenge was met by the Prest-O-Lite Company, who devised a method involving the compression of acetylene to 300 p.s.i. into a cylinder packed with a solid absorbent saturated with. acetone. 

Acetylene—Burning, Acetylene—Cutting, Acetylene—Welding Sparks, harmful rays, molten metal, flying particles 7, 8, 9. 

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