Why oxygen is used in gas cutting? Pure oxygen, instead of air, is used to increase the flame temperature to allow localized melting of the workpiece material (e.g. steel) in a room environment. In oxy-fuel cutting, a torch is used to heat metal to its kindling temperature.
What is oxygen fuel cutting process?
Oxy-fuel cutting is a thermal cutting process that uses oxygen and fuel gas (such as acetylene, propane, MAPP, propylene and natural gas) to cut through materials. Similarly, what is gas cutting process?
Why is pure oxygen used for cutting?
Pure oxygen, instead of air, is used to increase the flame temperature to allow localized melting of the workpiece material (e.g. steel) in a room environment. In oxy-fuel cutting, a torch is used to heat metal to its kindling temperature. Click to see full answer. Just so, which gas is used for cutting?
What gas is used for cutting?
The cutting method uses both oxygen and a cutting gas. But a variety of different gases are available. Oxy acetylene cutting has pretty much become synonymous with oxyfuel cutting. The reason is that this is the most common fuel used in the process. The main reason for that is the temperature it can achieve – around 3200° C.
How does an oxygen blasting machine cut metal?
When cutting, the metal is first heated by the flame until it is cherry red. Once this temperature is attained, oxygen is supplied to the heated parts by pressing the oxygen-blast trigger. This oxygen reacts with the metal, forming an oxide and producing heat. It is the heat that continues the cutting process.
What is the process of cutting oxygen?
How does oxygen jet work?
What are the gases used in combustion?
What is the reaction of fuel gas?
What is the role of nozzle design in oxygen?
Which has a greater stoichiometric oxygen requirement: acetylene or propane?
Which has a lower flame temperature, acetylene or propane?
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What is the purpose of oxygen level in gas cutting?
Pure oxygen, instead of air, is used to increase the flame temperature to allow localized melting of the workpiece material (e.g. steel) in a room environment.
Which gases are used in gas cutting?
Oxyfuel Cutting GasesAcetylene. Oxy acetylene cutting has pretty much become synonymous with oxyfuel cutting. ... Propane. Another fuel gas which can reach quite high temperatures. ... Propylene. Propylene is fast catching up with acetylene in the extent of use for flame cutting. ... MAPP. ... Natural Gas.
What type of oxygen is used for cutting torch?
Oxy Propane Oxygen and Propane fuelled kits are however, ideal for Silver Solder, Brazing, Cutting and Heating.
What are uses of oxygen?
Common uses of oxygen include production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy, and life support systems in aircraft, submarines, spaceflight and diving.
Why LPG is not used for gas cutting?
Because there are chances of leakage of liquid from the cylinder if the cylinder kept in lying position, so that there are chances of catching fire in tube and other combustible material. Even the cylinder can burst and can cause damage to the entire house and life of the personnel using the cylinder.
Does acetylene burn without oxygen?
Decomposition is a chemical reaction whereby acetylene breaks down into its constituent elements, carbon and hydrogen. This reaction gives out a great deal of heat, which can cause the gas to effectively ignite without the presence of air or oxygen.
Can oxygen cause a fire?
Oxygen is not flammable, but it can cause other materials that burn to ignite more easily and to burn far more rapidly. The result is that a fire involving oxygen can appear explosive-like.
Do you have to use oxygen with acetylene?
In this type of welding, the heat necessary for the process is produced by the combustion of oxygen and acetylene. Sometimes, hydrogen, butane, and propane are also used as replacements of acetylene. The combination of oxygen and acetylene to cut metals has been in use since approximately 1906.
Setup and Shutdown Procedure for Oxy- fuel Cutting Torch
CAPTION 7. THE INSTRUCTOR CHECKS IF ACETYLENE IS BEING SUPPLIED TO THE TORCH. Lighting the Oxy-fuel torch 1. Turn the acetylene knob on the cutting torch about a quarter of a turn and light the acetylene.
Safe Operating Procedures SOP 15 Oxy Acetylene Cutting & Welding
Safe Operating Procedures This SOP should be used in conjunction with relevant machinery manuals and manufacturer recommendations. Procedure
Required equipment
In order to use a gas cutter, you need to have at least one propane and oxygen cylinder, hoses designed for high pressure, a cutter. Each cylinder comes complete with a reducer, with which you can adjust the gas flow. The propane tank is reverse-threaded, so it is not possible to use another reducer on it.
Types of gas cutting of metal
The technologies of the modern world have made great strides forward. Now anyone can cope with the gas cutting procedure, because it is much easier than gas welding, so almost no skills are required for admission. The main thing to understand is gas cutting technology.
Special moments in cutting
Metal cutting technology says that there is no need to rush to open the valve of the propane cutter, because in this case, you expose yourself to the danger that can arise from the interaction of oxygen with a heated metal.
How is cutting done?
Cutting is performed with simultaneous heating. For this very purpose, the torch tip has 3 nozzles. The lateral ones are used to supply the heating mixture, and the thinnest nozzle is located in the center, through which oxygen is supplied under very high pressure.
Safety engineering
You need to understand that cutting metal with gas is a process that even a beginner can master, but this process does not become less dangerous. Therefore, training can only be carried out under the supervision of an experienced specialist.
Advantages and disadvantages of oxy-fuel cutting
Oxy-fuel cutting of metal has the following advantages: the ability to cut thick sheets and products; the possibility of surface treatment of the material; speed of work.
Gas consumption when cutting metal
Gas consumption to cutting volumes depends primarily on the selected method of carrying out the operation. For example, air arc efficient metal cutting involves more gas use than oxygen flux metal cutting. Also, the consumption depends on the following parameters:
Types of gas cutting of metal
The technologies of the modern world have made great strides forward. Now anyone can cope with the gas cutting procedure, because it is much easier than gas welding, so almost no skills are required for admission. The main thing to understand is gas cutting technology.
How is cutting done?
Cutting is performed with simultaneous heating. For this very purpose, the torch tip has 3 nozzles. The lateral ones are used to supply the heating mixture, and the thinnest nozzle is located in the center, through which oxygen is supplied under very high pressure.
Special moments in cutting
Metal cutting technology says that there is no need to rush to open the valve of the propane cutter, because in this case, you expose yourself to the danger that can arise from the interaction of oxygen with a heated metal.
Required equipment
In order to use a gas cutter, you need to have at least one propane and oxygen cylinder, hoses designed for high pressure, a cutter. Each cylinder comes complete with a reducer, with which you can adjust the gas flow. The propane tank is reverse-threaded, so it is not possible to use another reducer on it.
Safety engineering
You need to understand that cutting metal with gas is a process that even a beginner can master, but this process does not become less dangerous. Therefore, training can only be carried out under the supervision of an experienced specialist.
Gas cutting of metal with propane
Gas cutting of metal with propane is the most effective and popular type of cutting, since it does not need a special room, the presence of a grounding cable, moreover, it remains mobile when moving. Propane gas is used to heat the metal, and oxygen separates the metal. The heating temperature during gas cutting of metal with propane is 1000.
Oxygen cutting: types and subtleties of the work process
In our time, separative oxygen cutting of metal (possible with propane) has earned special distribution. Oxy-fuel cutting technology allows the technique to be used almost everywhere. Oxygen treatment is performed using a jet perpendicular to the surface (cut) or inclined (for beveling the edges).
What happens when you cut with oxygen?
When cutting with oxygen, the material is burned and vapourised after being heated up to ignition temperature by the laser beam. The reaction between the oxygen and the metal actually creates additional energy in the form of heat, which supports the cutting process.
What gas is used for laser cutting?
Laser cutting depends on an assist gas, which may be active or inert. Oxygen is the standard active assist gas used for laser cutting of mild and carbon steels. It is also referred to as the cutting gas. When cutting with oxygen , the material is burned and vapourised after being heated up to ignition temperature by the laser beam.
What is the purity of O2?
Maximising Productivity with the Right O2 Purities. Industrial oxygen is typically supplied in cylinders with a minimum purity of 99.5%. Generally speaking, this is not sufficient for laser cutting as it does not result in the best cut quality or the fastest cutting speeds.
What are the factors that determine the success of gas cutting?
The successfulness of gas cutting process depends upon two factors: ADVERTISEMENTS: (i) It employed only when the ignition (oxidation) temperature of the metal being cut is lower than its melting point. (ii) The process involves ensuring that the melting points of the formed oxides are lower than that of the base metal itself.
What is the name of the slot cut by the high pressure stream of oxygen?
A uniform wide slot, called kerf, is cut by the high pressure stream of oxygen. The marking on the sides of the keft are called drag as shown in Fig. 7.42. If the speed of travel of torch is high, the bottom cut lags behind the top cut and the drag lines are curved.
What is the purpose of hose fittings?
Hose and hose fittings are used to carry the gases from cylinder to cutting torch. 5. Goggles and Glasses: Goggles fitted with coloured lenses are used to protect the operator eyes from ultraviolet and harmful infra-red radiations.
What gas is used in a fire?
Although acetylene is commonly used as a fuel in this process, other gases can also be used including butane, methane, propane, natural gas. Hydrogen is sometimes used as a fuel gas, especially under water to provide a powerful pre-heating flame.
What is the function of a gas regulator?
The function of regulator is to regulate the coming gas pressure, to the required working pressure. They also serve the function of supplying the gas at constant flow rate. 3. Gas Cylinders: Like gas welding, two gas cylinders, one for oxygen and other for acetylene are used. 4.
What is the drag line on a cut?
A correctly made cut will have parallel and evenly spaced drag lines and square edges . These drag lines indicates the quality and speed of travel. Drag lines are expressed as a percentage of the thickness of metal being cut. Only 10 – 12% drag is allowed during cutting.
What is the function of a high pressure valve?
On pressing the lever, the high pressure valve releases a jet of oxygen from central orifice, after preheating. 2. Pressure Regulators: Pressure regulators and fitted on the top of the cylinders and carry a valve. The function of regulator is to regulate the coming gas pressure, to the required working pressure.
What is oxy fuel cutting?
In addition, oxy-fuel cutting is still widely used, both in heavy industry and light industrial and repair operations. In oxy-fuel welding, a welding torch is used to weld metals. Welding metal results when two pieces are heated to a temperature that produces a shared pool of molten metal.
What are the gases used in oxyfuel?
Other gases that may be used are propylene, liquified petroleum gas (LPG), propane, natural gas, hydrogen, and MAPP gas. Liquid fuel cutting systems use such fuels as Gasoline (Petrol) Diesel, Kerosene and possibly some aviation fuels.
How thick can a torch cut steel?
Tests showed that an oxy-gasoline torch can cut steel plate up to 0.5 in (13 mm) thick at the same rate as oxy-acetylene. In plate thicknesses greater than 0.5 in (13 mm) the cutting rate was better than that of oxy-acetylene; at 4.5 in (110 mm) it was three times faster. Operating cost for a gasoline torch is typically 75-90% LESS than using propane or Acetylene.
What is an acetylene generator?
Acetylene generator as used in Bali by reaction of calcium carbide with water. This is used where acetylene cylinders are not available. The term 'Las Karbit' means acetylene (carbide) welding in Indonesian.
What is hydrogen gas used for?
It can be used at a higher pressure than acetylene and is therefore useful for underwater welding and cutting. It is a good type of flame to use when heating large amounts of material. The flame temperature is high, about 2,000 °C for hydrogen gas in air at atmospheric pressure, and up to 2800 °C when pre-mixed in a 2:1 ratio with pure oxygen (oxyhydrogen). Hydrogen is not used for welding steels and other ferrous materials, because it causes hydrogen embrittlement .
What is the apparatus used in welding?
Apparatus. The apparatus used in gas welding consists basically of an oxygen source and a fuel gas source (usually contained in cylinders ), two pressure regulators and two flexible hoses (one for each cylinder), and a torch. This sort of torch can also be used for soldering and brazing.
How far apart should oxygen hoses be clipped?
If separate hoses are used, they should be clipped together at intervals approximately 3 feet (1 m) apart, although that is not recommended for cutting applications, because beads of molten metal given off by the process can become lodged between the hoses where they are held together, and burn through, releasing the pressurised gas inside, which in the case of fuel gas usually ignites.
How the Oxy-Fuel Cutting Process Works
The oxy-fuel cutting process is capable of cutting steel whose composition is less than .3% carbon. Mild steel is comprised of 98% iron, 1% manganese, carbon up to .3% and various other elements in small amounts. Oxy-fuel cutting cannot cut non-ferrous metals such as aluminum, stainless, brass or copper.
Oxygen Purity
Single piece cutting tips are normally designed for cutting with acetylene. Single piece tips are copper with a drilled and swaged hole for the center cutting oxygen flow and four to six drilled holes for the preheat gas flow.
Straight and Divergent Bore
Straight bore tips typically use between 40 – 60 PSI of cutting oxygen. Machine cutting tips are typically divergent bore tips with a tapered or flared outlet hole. Divergent bore tips use 70 – 100 PSI of cutting oxygen and offer 25% increase in cutting speed over straight-bore tips.
How does oxyfuel work?
Cutting Process. The oxyfuel cutting process takes place in 3 steps: Preheating of metal. Oxidation of metal. Blowing away the slag. First, a mixture of cutting gas and oxygen is directed onto the work piece through a cutting torch to preheat it.
What is flame cutting?
Flame cutting is a thermal metal cutting method. Its primary advantage is the ability to cut very thick metal plates – usually up to 150 mm. In extreme cases, the metal thickness can go much (e.g. 1200 mm) above the aforementioned figure but this is not available with every manufacturer. The only other comparable cutting method is waterjet ...
Why is flame cutting not good for stainless steel?
A chemical reaction occurs after igniting the metal, resulting in oxidation. And here lies the reason why flame cutting is not suitable for cutting stainless steel. Lastly, the high-pressure oxygen jet blows away the slag, or iron oxide, cutting the metal in the process.
Why is propylene better than acetylene?
Also, propylene is actually quicker for cutting, producing less slag in the process. The flame temperature is around 2900° C.
What gas can reach a high temperature?
Propane. Another fuel gas which can reach quite high temperatures. The maximum is around 2800° C. Compared to acetylene, the concentration of the flame is smaller, resulting in a larger HAZ and longer piercing time. The cutting speed is comparable, though. The ratio of oxygen to propane is around 4.3:1.
Is LPG good for cutting?
The slowest one on the list for piercing and cutting. LPG, though, is quite readily available commercially and is therefore a good alternative to the other fuel gases here on the list.
Is oxyfuel cheaper than waterjet?
While oxyfuel cutting is only suitable for a few metals, waterjet can cut pretty much anything. However, oxyfuel cutting is a lot cheaper than waterjet.
What is the process of cutting oxygen?
Oxyfuel cutting - process and fuel gases. Oxy-fuel cutting is a thermal cutting process that uses oxygen and fuel gas (such as acetylene, propane, MAPP, propylene and natural gas) to cut through materials.
How does oxygen jet work?
A jet of pure oxygen is then directed into the preheated area instigating a vigorous exothermic chemical reaction between the oxygen and the metal to form iron oxide or slag. The oxygen jet blows away the slag enabling the jet to pierce through the material and continue to cut through the material. Fig.1.
What are the gases used in combustion?
The five most commonly used fuel gases are acetylene, propane, MAPP (methylacetylene-propadiene), propylene and natural gas. The properties of the gases are given in the Table. The relative performance of the fuel gases in terms of pierce time, ...
What is the reaction of fuel gas?
In the inner cone or primary flame, the fuel gas combines with oxygen to form carbon monoxide and hydrogen which for acetylene, the reaction is given by. Combustion also continues in the secondary or outer zone of the flame with oxygen being supplied from the air.
What is the role of nozzle design in oxygen?
Thus, nozzle design plays a significant role in protecting the oxygen stream from air entrainment.
Which has a greater stoichiometric oxygen requirement: acetylene or propane?
Propane has a greater stoichiometric oxygen requirement than acetylene; for the maximum flame temperature in oxygen, the ratio of the volume of oxygen to fuel gas are 1.2 to 1 for acetylene and 4.3 to 1 for propane. Fig.2. Ocyacetylene gas jet and nozzle design. Fig.3.
Which has a lower flame temperature, acetylene or propane?
Propane. Propane produces a lower flame temperature than acetylene (the maximum flame temperature in oxygen is 2,828°C compared with 3,160°C for acetylene). It has a greater total heat of combustion than acetylene but the heat is generated mostly in the outer cone ( see Table ).
