High-resolution, full color images available online
Search, browse, read, and print yearbook pages
View college, high school, and military yearbooks
Browse our digital annual library spanning centuries
Support the schools in our program by subscribing
Privacy, as we do not track users or sell information
Page 27 text:
“
Oxy-Acetylene Welding and Cutting THE process of uniting metals by means of reducing the edges to be welded to a molten state, and uniting them without pressure or hammering is called autogenous welding. This is, at the present time, done either by means of the electric arc, or by the oxy-acetylene, and burning them, producing an intense- ly hot atmosphere immediately surrounding the spot to be welded. Acetylene is a gas, more or less familiar to all in lie form of Piestolite tanks, formerly used for lighting automobiles. This gas is made from calcium carbide, which is in turn produced in the electric arc. When water is applied to calcium carbide, a chemical reaction takes place in which calcium oxide, or common quicklime, is produced, while acetylene gas is freed. This gas is composed of hydrogen and carbon, both of which are very easily and completely oxidized, pro- ducing a very intense heat. However, when hydrogen and oxygen unite a certain temperature is reached at which the water formed by the reaction again decom- poses into hydrogen and oxygen. This is obviously the highest temperature possible to obtain with this reac- tion. and so in the oxy-acetylene torch the burner is so designed that only the carbon in the acetylene unites with the oxygen, while the hydrogen takes its oxygen from the air, thus surrounding the intensely hot core of the flame with an outer flame that prevents the metal being worked on, from being oxidized by oxygen in the air. Oxygen is one of the constituents of the air. and also of water, and commercial oxygen, for use in welding is produced from one or the other of these substances. In a cell especially designed to prevent the two gases from mixing, water is decomposed by electrolysis into hyd- rogen and oxygen. If the gases are not kept absolutely distinct and separate, an extremely explosive mixture is the result, which, after it is compressed into cylinders to be shipped, may explode, doing tremendous damage. It sometimes happens that several of these cells are connected up to a single compressor, and if the poles of the electrical circuit are reversed on one or more cells, it has the result of mixing the gases together. Another way of obtaining oxygen is by compressing and cooling air until it is liquid, when the nitrogen can be separated from the oxygen, having a lower boiling point. This is the safest way, as it is obviously impos- sible to mix any combustible gas with the oxygen. For a long time, although the process was known, oxy-acetylene welding and cutting was not extensively used because no satisfactory method had been found to transport acetylene gas, which cannot be compressed to more than fifteen pounds, without great danger. Then someone discovered that it could be dissolved in acetone, which would dissolve nearly two hundred vol- umes of it under considerable pressure, that being used at the present time being about 250 pounds per square inch. So the cylinders in which commercial acetylene gas is shipped, are not merely filled with the gas. nor are they content merely with acetone, as if that were the case, the acetone, being a liquid would run out if the cylinder were used in a horizontal position. So the cylinders are filled with asbestos, and arc tone is poured in until the asbestos is saturated, when the gas is punio- ed into the acetone. This makes it possible to safely ship a very large amount of gas in a small cylinder. Be- fore this was developed, acetlyene had to be produced on the individual job it was to be used on. by means of clumsy, expensive and unsatisfactory generators, which do not produce a gas pure enough to produce a good 23
”
Page 28 text:
“
weld, unless a large investment is made in apparatus to purify the gas before it is burned. There is almost no limit to the field in which this process of welding can be used. It is very true that under certain conditions it is cheaper to use the electric arc process, but this calls for a comparatively large in- vestment, far beyond the means of most small shops and garages. Thermit, also excels on very large pieces of work, where time is no particular object, as the results are somewhat more certain. However, it requires near- ly three days to make a weld with thermit, which the oxy-acetylene man could do in as many hours. An- other tremendous advantage is that a weld can be made, in many instances, without removing the pieces from its original position. This is very important, when the tie up of the machine in question ties up a considerable number of men. or holds up valuable production. One field which the various other methods of welding will never be able to successfully invade without great improvement in present methods, is in welding pipe lines, as this calls for a very portable outfit, and no other process is able to advance this claim for itself. It is possible to weld instead of screw up a pipe line in nearly the same length of time, and at far less cost; for if a threaded joint leaks, there is nothing to do but cut the pipe, run new threads, and put on a union all of which is no little job. as anyone who has tried it is well aware. A welded joint, on the other hand, if it is found to leak. can. in the great majority of cases, be stopped merely by the use of a center punch. If the leak is too serious to be handled in this manner all that is necessary is to go over that spot with the torch, and this can be done without removing the pipe from its original postion. A weld can be made in a vertical plane, or even directly overhead. Thus pipe can be rolled over and over by a wrench, and welds made di- rectly on top, which is the easiest and fastest position until the pipe gets too long and heavy, when the final 24 joints are put in without turning the pipe at all. Another important use of the process is that almost all kinds of metal can be welded, many of which can- not be attempted by the old time blacksmith forge. Among these are aluminum, copper, cast iron, and var- ious alloy steels. Hundreds of castings which would previously have been thrown away, are now being re- claimed, and castings which have blowholes in them are repaired instead of melting them up. Another field in which oxy-acetylene process is ab- solutely supreme in cutting. This is done by heating the metal to be cut. to a high heat, and then blowing pure oxygen against it. This unites with the iron form- ing iron oxido, which is blown out of the cut. Iron plates can be cut faster than a carpenter can cut the same thickness of wood. By means of it one can cut away portions of a piece of work, preparatory to weld • ing. Structural iron and steel can be cut, and this is very useful in scraping this material, in clearing away wrecks, and in all sorts of emergency work, such as where men are imprisoned under wreckage, as a bar can be cut in two without heating it more than throe inches either way. Thus a cut can be made very close to a man, who is caught, without burning him. Although with the further development of the elec- tric arc, it is bound to surplant the oxy-acetylene, par- ticulary in shop work and where the work can be brought to the machine, there is never the less a very broad field for the development of acetylene welding, as it is absolutely without peer in its special field. We may look for many developments in the process in the near future, as it is far from perfect, but a great deal of research work is being done all the time, and every year sees many valuable improvements, and a widening of tbe field of its usefulness. THEODORE WALKER.’19.
Are you trying to find old school friends, old classmates, fellow servicemen or shipmates? Do you want to see past girlfriends or boyfriends? Relive homecoming, prom, graduation, and other moments on campus captured in yearbook pictures. Revisit your fraternity or sorority and see familiar places. See members of old school clubs and relive old times. Start your search today!
Looking for old family members and relatives? Do you want to find pictures of parents or grandparents when they were in school? Want to find out what hairstyle was popular in the 1920s? E-Yearbook.com has a wealth of genealogy information spanning over a century for many schools with full text search. Use our online Genealogy Resource to uncover history quickly!
Are you planning a reunion and need assistance? E-Yearbook.com can help you with scanning and providing access to yearbook images for promotional materials and activities. We can provide you with an electronic version of your yearbook that can assist you with reunion planning. E-Yearbook.com will also publish the yearbook images online for people to share and enjoy.
