The LPG (propane) is a blue flame because complete combustion creates enough energy to excite and ionize the gas molecules in the flame.
The color blue indicates a temperature even hotter than white. Blue flames have more oxygen and get hotter because gases burn hotter than organic materials, such as wood. When natural gas is ignited in a stove burner, the gases quickly burn at a very high temperature, yielding mainly blue flames.
It has a yellow or yellowish color due to carbon or hydrocarbons which bind with (or reduce) the oxygen contained in the materials processed with the flame.
An eternal flame is a flame, lamp or torch that burns for an indefinite time. In ancient times, eternal flames were fueled by wood or olive oil; modern examples usually use a piped supply of propane or natural gas. They consume oxygen, transforming it to carbon dioxide.
Like the incandescent soot in a luminous flame, the mantle is heated and then glows. The flame does not provide much light itself, and so a more heat-efficient non-luminous flame is preferred.
Cutting torches for use in cutting machines usually are fitted with two oxygen inlet connections, with oxygen supplied through separate regulators. As in the case of welding torches, cutting torches are offered with two types of mixers: the injector type, and the medium-pressure type.
We recommend closing the oxygen valve first whenever turning off an oxy-fuel torch system especially when Acetylene is fuel.
Oxy-acetylene welding has become less popular in industrial applications over the years, but is still used extensively in field and shop work. Oxy-acetylene is quite common in automotive repair shops, as well as plumbing applications, fabricating, and even artisan welding.
about 3,480 degrees Celsius
Oxygen does not burn. It is not flammable, but it is an oxidizer. Oxygen feeds fire, so it's dangerous to use around something that is burning because it will help the fire burn much more quickly. Patients on oxygen therapy who are smokers are not going to burst into flame or explode if they smoke.
Consumer air butane torches are often claimed to develop flame temperatures up to approximately 1,430 °C (2,610 °F). This temperature is high enough to melt many common metals, such as aluminum and copper, and hot enough to vaporize many organic compounds as well.
Because of its high endothermic heat of formation, it can explode to carbon powder and nitrogen gas, and it burns in oxygen with a bright blue-white flame at a temperature of 5260 K (4990 °C, 9010 °F), the hottest flame in oxygen; burnt in ozone at high pressure the flame temperature exceeds 6000 K.
Cards
| Term 1. What elements make up all hydrocarbons? | Definition Hydrogen & carbon. |
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| Term 13. Which fuel gas has the strongest odor and is easiest to detect? | Definition MAPP |
| Term 14. What is the major advantage of using propane or natural gas? | Definition For heating, and natural gas does not have cylinders. |
Metals such as aluminum and stainless steel cannot be cut with Oxy/fuel due to the formation of an oxide that prevents oxidation from fully occurring.
Advantages of Oxy-Acetylene Welding :
- It's easy to learn.
- The equipment is cheaper than most other types of welding rigs (MIG/TIG welding)
- The equipment is more portable than most other types of welding rigs (MIG/TIG welding)
- Oxy/Acetylene equipment can also be used to "flame-cut" large pieces of material.
What is the difference between a harsh flame and a quiet flame? A harsh flame is produced by using too much pressure of both gases to the tip, and it is noisy; a quiet flame has the correct amount of pressure and it does not make any noise.
A reducing oxyfuel gas flame in which there is an excess of fuel gas, resulting in a carbon rich zone extending around and beyond the cone. A carburizing flame is used in hardfacing and similar processes to obtain fusion between base metal and weld metal without deep melting of the base metal.
Gases used in welding and cutting processes include: shielding gases such as carbon dioxide, argon, helium, etc. fuel gases such as acetylene, propane, butane, etc. oxygen, used with fuel gases and also in small amounts in some shielding gas mixtures.
The neutral flame burns at approximately 5,850 °F at the tip of the inner luminous cone and is produced by a balanced mixture of acetylene and oxygen supplied by the torch. The neutral flame is used for most welding because it does not alter the composition of the base metal.
Set your oxygen to 40-50 psi. Turn your oxygen valve on all the way, then turn your acetylene valve a 1/6-1/5 of a turn. Using your striker light the torch facing away from you and the bottles. Adjust the acetylene valve to where the flame is touching the tip of the torch, but is not giving off black smoke.
The reason that an oxyacetylene cutting torch will pop and go out is because of a problem with gas flow. Usually this is either an issue with flow settings, a leak or blockage.
The tank pressure gauge is responsible for telling you how full the tank is. In order to tell if a welding tank is almost empty, read the gauge! Often measured in pound-force per square inch (psi), the gauge will tell you that the pressure is decreasing.
Look on your cylinder; there is a tare weight stamped. Weigh the cylinder and subtract the tare weight. Acetylene is 14.5 cu. ft. /#, so you can find out how much you have.
Each type of welding requires special gas. In the US, hoses for acetylene, propane and other gases used as fuel must be red, and oxygen must be green. In addition to the differing colors, the red fuel hoses have a left-hand thread, and the green oxygen hoses have a right-hand thread.
What is the best way to set the oxygen pressure for cutting? Increase the pressure slowly and readjust the flame as you watch the length of the clear cutting stream in the center of the flame.
The pressure in an oxygen cylinder can be as high as 2200 psi (15,169 kPa), which must be reduced to a working pressure of 1 to 25 psi (6.90 to 172.38 kPa). The pressure of acetylene in an acetylene cylinder can be as high as 250 psi (1724 kPa).
In welding or cutting, the oxygen/acetylene-focused flame is necessary because the heat needs to be concentrated at a small point. Since the highest temperature is focused at the end of the inner cone, if oxygen/acetylene is being used for brazing, the torch must be kept in motion to evenly distribute heat.
