The cylinder is then baked, and the mixture forms a porous, spongelike mass. Because this is achieved by oxidation, it is only effective. Heating the metal is caused by an acetylene flame that adds oxygen to burn the metal. Video an introduction to gas welding oxyacetylene oxyacetylene gas welding is commonly used to permanently join mild steel. Oxy acetylene brazing, torch adjustments reducing flame. Open the acetylene blowpipe handpiece valve very slightly and light with a flint lighter only. In modern steelage the steelmakers cut iron and steel by oxy acetylene, oxy hydrogen, oxy propane, oxy natural gas cutting blowpipes easily, speedily, and cleanly. This means if acetylene reaches 30 psi in a free state, it can explode by itself without a spark or flame being present. You can produce a neutral flame by increasing the acetylene flow until the flame. It is acceptable to use acetylene regulators that indicate a static pressure up to 22 psi 151 kpa. It obtains additional oxygen from the air and provides complete combustion. Nov 07, 2018 gas weldingoxy acetylene,equipment details,types of flames,applications gas welding process pdf.
Adjust acetylene to bring flame back down to almost touching the tip. Safety for oxyacetylene welding thompson rivers university. Jan 25, 2017 oxy acetylene welding is a very common welding process that dates back to 1890s, wherein oxygen and acetylene are used as the two major welding gases. The preheat flame is composed of fuel gas and oxygen at a proper mixture ratio to produce maximum flame temperature for greatest heating efficiency. Definition, equipment, flames, working, types, advantages, disadvantages, applications in detail note. If you light up the tip and the flame is away from the tip, decrease the acetylene pressure and let the flame. The oxy coalgas flame is very similar and consists of hydrogen with other impurities. Hydrogen burns in air with a blue, nonluminous flame to form water. Oxy acetylene welding is a welding process manually, in which the surfaces to be joined, which is warming to melt by a gas flame oxyacetylene with or without filler metal, where the connection. For example, from equation 1, above, the reaction products of the oxy acetylene flame.
To secure a neutral flame, always start with an excess of acetylene, then increase the flow of oxygen or decrease the flow of acetylene until the acetylene feather disappears from the center cone. Safe operating procedures sop 15 oxy acetylene cutting. Always be very aware of the dangers of a naked flame. Aug 30, 2019 an oxy acetylene torch is an affordable and versatile tool used by many people to heat, weld, solder, and cut metal. Slowly open the oxygen blowpipe headpiece valve until a neutral flame is produced. Mapp gas is a mixture of various hydrocarbons, principally, methylacetylene and propadiene. For welding the mild steel, open oxygen torch valve and adjust to neutral flame. In this welding process, mostly oxy acetylene gas is used as a working fuel gas. Depress oxygen lever and make necessary adjustments. Gas weldingoxy acetylene,equipment details,types of flames,applications gas welding process pdf.
Oxy fuel cutting uses acetylene and oxygen to preheat metal to red hot and then uses pure oxygen to burn away the preheated metal. Welding and cutting steel oxy acetylene and other methods. An excess of acetylene is easy to spot, but an excess of oxygen is difficult to spot except that it will cause molten metal to spark excessively. It can be used for cutting steel, welding steel, brazing and for heating metal. In the weld shop, we use machines that will cut pipe form 2 inches to 14 inches in diameter. Shutting down the torch with a positiveequal pressure mixer. Safety in gas welding, cutting and similar processes.
Other gases, fuel such as mapp gas, propylene, propane, natural gas, and proprietary gases based on these, have sufficiently high flame temperatures but exhibit low flame. Cutting with the oxy fuel process is just the opposite from of welding. When the amount of acetylene reduces from natural flame or amount of oxygen increases, the inner cone tend to disappear and the flame obtain is known as oxidizing flame. Under pressure, dissolved acetylene is safe, but free acetylene over 15 psi pressure is unsafe. The difference between acetylene vs lpg propane as a. Combustion of acetylene with oxygen produces a flame of over 3,600 k 3,330 c. Oxyacetylene cutting safety occupational safety and. The oxycoalgas flame is very similar and consists of hydrogen with other impurities. See all 26 photos to set the flame, open the acetylene valve on the torch body about 14 turn. When mixed together in correct proportions within a handheld torch or blowpipe, a hot flame is produced with a temperature of about 3,200c. At this stage, acetylene and oxygen of similar equal quantities are being used and combustion is completed.
Pdf welding and cutting steel oxyacetylene and other. In oxyhydrogen flame, hydrogen is burnt in a stream of oxygen. It uses extreme heat to function, and setting it up properly is. When mixed together in correct proportions within a handheld torch or blowpipe, a relatively hot flame. A flashback flame arrestor is a device that prevents the propagation of a flame. Approximately 20% of acetylene is supplied by the industrial gases industry for oxyacetylene gas welding and cutting due to the high temperature of the flame. The function of each type however is to apply heat to material via a flame created at the nozzle or the cutting tip. A flashback flame arrestor is a device that prevents the propagation of a flame upstream. The flame you see with oxyacetelyne is the same temperature as the surface of the sun, which means its radiating far more into the ultraviolet range than a oxypropane flame is. When mixed together in correct proportions within a handheld torch or blowpipe, a relatively hot flame is produced with a temperature of about 3,200 deg.
If you light up the tip and the flame is away from the tip, decrease the acetylene pressure and let the flame come back against the tip. Check oxy fuel system for leaks with an approved leak detection solution or leak detector. Oxygen acetylene welding, or gas welding, is a process which relies on combustion of oxygen and acetylene. Removing deformations with an oxy acetylene flame this process is based on the physical principle that metals expand when heated and contract when cooled. Oxyacetylene welding is simple in concept two pieces of metal are brought together, and the touching edges are melted by the flame with or without the addition of filler rod. Adjustment is made by adding more or less oxygen to the acetylene flame. The chemical action of the oxyacetylene flame can be adjusted.
Careless use of oxy fuel torches has caused many fires. Oxy acetylene cuts metal by utilizing oxygen to burn metal. The inner zone has very bright white color and has temperature of about 3300 degree centigrade. The welder can adjust the oxy acetylene flame to be carbonizing aka reducing, neutral, or oxidizing. Turn on acetylene regulator and adjust to 35 psi 15 psi maximum. How to set up an oxy acetylene torch with pictures wikihow. It uses extreme heat to function, and setting it up properly is one of the most important steps in using it safely. If the oxy welding cutting equipment is to be operated in a dangerous. The neutral flame is characterized by a temperature around 3200 degrees celsius 5900 degrees f, the absence of a hissing noise, a light blue outer flame and a sharp inner white flame. Mediumduty oxyacetylene cutting and welding outfit 770 502. It is a welding process that melts and joins the metals by heating them with a flame.
Oxy acetylene can be used on sites with no power supply it is quite a versatile process and can be used to weld most metals. A welding torch is used in the joining of materials, whereas the cutting torch is used in the separation of materials. If a flame is formed the temperature is about 2,8003,000c. Oxy fuel welding commonly called oxyacetylene welding, oxy welding, or gas welding in the united states and oxy fuel cutting are processes that use fuel gases or liquid fuels such as gasoline and oxygen to weld or cut metals. Acetylene regulator should be set to deliver only 10 psi o close both oxygen and acetylene cylinder valves o turn adjusting mechanism counterclockwise one. Flame straightening is an efficient, wellestablished method of correcting the weld distortion without impairing the material. Safety in gas welding, cutting and similar processes page 3 of 11 preventing fire from heat, sparks, molten metal or direct contact with flame the flame from an oxy fuel gas torch often called a blowpipe is a very powerful source of ignition. This heat is used to melt interface surfaces of welding plates which are held together to form a joint. Oxy acetylene welds have large heat affected zones areas around the weld line that have had their mechanical properties adversely affected by the welding process there are safety issues with oxy acetylene as there is a naked flame.
Apr 03, 2017 how to set the oxy acetylene regulators duration. Oxyfuel oxyacetylene welding a guide to gas welding twi. When it is applied to steel, the oxidizing flame causes oxyacetylene cutting is the most commonly used. Pass a written test on safety and operation procedures on the oxy acetylene. Continue to add oxygen until neutral flame is established. How to cut metal with an oxy acetylene cutting torch. After the acetylene cylinder is built, a wet cement mixture of various materials, such as asbestos or charcoal, is packed into the cylinder. Turn the acetylene knob on the cutting torch about a quarter of a turn and light the acetylene. If there is too much acetylene, flame breaks away from the tip. Acetylene regulator should be set to deliver only 10 psi o close both oxygen and acetylene. At the end of the articles you will find the download pdf button that you can easily download pdf. The neutral flame is the flame most generally used when welding or cutting.
The neutral flame has a clear, welldefined, or luminous cone indicating that combustion is complete. The chemical action of the oxy acetylene flame can be adjusted. In oxy hydrogen flame, hydrogen is burnt in a stream of oxygen. Removing deformations with an oxy acetylene flame this. Using matches to light the torch brings your fingers too close to the tip.
In order to comfortably and safely see the flame when welding or cutting, welding goggles must be worn. Pass a written test on safety and operation procedures on the oxy acetylene unit with a minimum of 100 accuracy. Dec 17, 2019 the neutral flame has a onetoone ratio of acetylene and oxygen. In fact, the oxyacetylene flame burns at 6000 f, and is the only gas flame that is hot enough to melt all commercial metals. Oxy acetylene welding ofw fundamentals pressure settings. Fundamentals of gas cutting and welding ced engineering. As the supply of oxygen to the blowpipe is further increased and the flame contracts, a white cone will become clearly defined, assuming a definite rounded shape. Among the commercially available ofw, oxy fuel welding fuel gases, acetylene a combination of hydrogen and carbon most closely meets all these requirements. Oxyacetylene welding, commonly referred to as gas welding, is a process which relies on combustion of oxygen and acetylene.
A mixture of oxygen and acetylene, burns as an intense focussed flame. Cutting of metals by means of flame has many advantages over other methods, specially when the metal is of irregular shape. Apr 17, 2017 when the amount of acetylene reduces from natural flame or amount of oxygen increases, the inner cone tend to disappear and the flame obtain is known as oxidizing flame. Oxy fuel cutting uses acetylene and oxygen to preheat metal to red hot and. Gas welding oxy acetylene,equipment details,types of flames,applications gas welding process pdf. It is a welding process that melts and joins the metals by heating them with a flame caused by a reaction of fuel gas and oxygen. Under pressure, dissolved acetylene is safe, but free acetylene. Similarly, highly reactive metals like titanium require inert gas shielding because titanium will react with oxy acetylene gas reactants. An oxy acetylene torch is an affordable and versatile tool used by many people to heat, weld, solder, and cut metal. In modern steelage the steelmakers cut iron and steel by oxyacetylene, oxyhydrogen, oxy propane, oxynatural gas cutting blowpipes easily, speedily, and cleanly.
Oxy acetylene welding leaving certificate engineering notes. Check valves and flashback arrestors are safety devices for protecting workers using oxyfuel cutting and welding equipment. It is hotter than natural flame and has clearly defined two zones. The oxy acetylene flame produces an intense bright light that causes discomfort and possible injury to the eyes. A check valve is a device that is designed to prevent the unintentional backflow of gases. Acetylene weld lines are rougher in appearance and need more finishing acetylene is unstable and expensive there are more safety issues with oxy acetylene, because there is a naked flame. Competencies given a functional oxy fuel gas unit, instruction and demonstration of use, each student will be able to. And it was precisely that the flame of the oxy acetelyne left spots.
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