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 process without emphasis. In addition to the purposes of welding (connecting), gas welding can also be used as preheating, brazing, cutting and hard facing. Use for production, field work, and reparations.
Oxygen Acetylene Welding (OFW) Process and Equipment :
In the application, the result is very satisfactory for welding carbon steel, mainly sheet metal and thin-walled pipes. Nevertheless, almost all types of ferrous and non-ferrous metals can be welded with welding gas, either with or without additives.
Besides acetylene gas is also used hydrogen gas, natural gas, propane, for metals with a low melting point. In the process of burning the gases needed oxygen. Oxygen is obtained from the air where the air itself contains oxygen (21%), also contain nitrogen (78%), argon (0.9%), neon, hydrogen, carbon dioxide, and other elements that form a gas.
Technically, the oxygen is obtained from liquefied air. Then, by means of electrolysis, a mixture of air and water are separated by liquid oxygen. The difficult problem is between Nitrogen and Oxygen. Greater nitrogen boiling point and the boiling point of the gas is the only differ 13 0C only. So that needs oxygen purification repeatedly. Purity can be achieved up to 99.5% and then used in steel tanks with a working pressure of 15-30 atm.
Making Oxy acetylene
In the commercial world, to produce a reaction Oxyacetylene do activities calcium carbide and water. Therefore, Oxyacetylene often called hydrocarbon gas consisting of carbon, lime and water. Oxyacetylene nature is odourless and colourless. Keep in mind that pure Oxyacetylene very susceptible to an explosion caused by pressure and temperature factors. For this reason, the Oxy-acetylene generator is limited to a maximum pressure of 5 atm.
Oxy Acetylene Welding Set Up and Pressure Settings Chart :
- The first we must Clean the nozzle, because if the head of nozzle dirty will cause flame bad.
- Open Regulator Oxygen and Acetylene, set until the pressure matching with what do you want or for acetylene 5 to 7 psi and Oxygen 7 to 10 psi.
- The third open valve in torch, first acetylene after that you can open oxygen valve. If the gas has out from nozzle you can use lighter and light the torch.
Types of Oxy-Acetylene Welding Flames :
- Carburizing Flame : For this type, we use more acetylene than oxygen. Carburizing flame use application to soldering, silver welding and braze welding.
- Neutral Flame : Pressure oxygen and acetylene same. This type can we use for steel welding.
- Oxidizing Flame : We use more oxygen than acetylene. Usually we use this flame for cutting materials from carbon steel.
Oxygen acetylene welding rods types :
For rods type there are RG-60, RG-45, RG-65. RG is Rod Gas and 65 is tensile strength 65.000 PSI.
|Metal Thickness (inch)||Tip Size|
|1/4 – 1/2||5|
|3/16 – 1/4||4|
|1/8 – 3/16||3|
|1/16 – 1/8||2|
|5/64 – 3/32||1|
|3/64 – 5/64||0|
|1/32 – 3/64||00|
|1/64 – 1/32||000|
Oxy Acetylene Welding Kit
- Multi fuelled torch.
- Comfortable grip handle
- Tip Cleaner
- Tough solid brass construction
- Flame stability
Flashback resistant mixer
- High flow oxygen cutting valve
- Suitable for light to medium duty cutting and welding
- Torch profile
- Gas hose
Gas storage cylinders
Because gases are stored in the bottle has a pressure greater than atmospheric pressure, it should be noted strength steel bottle against the pressures of work because they are causing friction and movement of gas in the bottle, it should be known types of gas, sensitive to shock or increase in temperature.
Defects in Oxygen acetylene welding.
To produce good quality, welding conditions should be running properly and the techniques and materials used must meet the standards. As is the case in other welding processes, welding defects can occur. Oxyacetylene welding disability as follows:
- Penetration is less than perfect, it can happen because the penetration is not performed on the entire thickness of the base metal, weld bead two are not mutually perform inter-penetrating and penetrating into the end of the fillet weld.
- Fusion is less than perfect, these deformities occur due to lack of or non-occurrence of metal smelting gas and base metals. It is usually caused by the welding speed is minimal or low gas pressure.
- Undercutting, occurs due to lack of precise parameters such as gas and welding speed is too high.
- Porosity can occur due to atmospheric contamination and high oxidation on the surface of the workpiece.
- Longitudinal crack the distinguished in two categories; heat cracks caused by the position of the weld bead is between the melting temperature and freezing temperatures. While the cold cracking occurs due to freezing weld bead.
Now you know, what is Oxy-Acetylene Welding. I hope the above article can helpful for you who study about Oxygen Acetylene Welding or OFW Welding.