This is the most common and one of the earliest method used for joining of the material in which mixture of two gases is burnt to get the flame for welding purposes. These two gases are oxygen and acetylene. As the oxygen is responsible for the combustion for any fuel and material, temperature can be varied according to the amount and percentage of the oxygen mixed in acetylene. The more will be the percentage of oxygen, the higher flame temperature will be achieved.

   In this type of welding material joining will be done by heating the two specimen up to a certain temperature where the coalescence will be achieved between the specimens.

The welding torch is used for the production of the flame in an appropriate shape and manner.
Filler material: - this is a metallic rod also called filler rod and used additionally to fill the metallic material between the two specimen. It can be of the same material as the material to be weld or can be different.

GAS WELDING ANIMATION

GAS WELDING COMPONENTS:-

1. CYLINDERS:-

•      In the gas welding the first and the most important component is cylinders. In oxyacetylene gas welding, there is a requirement of two cylinders. One is of oxygen and another is of acetylene. This is called main component because the other parts are actually attached with the cylinders. A trolley can be preferred for the movement and easy portability of the cylinders.
• There is a specific color used to paint on the welding cylinders for easy recognition. Generally oxygen cylinder is painted by red color. Any other color can also be used according to feasibility standards.
• In the acetylene cylinder there is also the use of acetone. Acetone helps the acetylene gas to be pressurized and to be in the cylinder in a safe manner.
• Because of acetone, the acetylene cylinder should never be kept horizontal, because the fuel is acetylene and only acetylene should be supplied to the cylinder. The acetone will remain at the bottom of the cylinder if it is kept vertical.

2.  HOSES: - 

Hoses are used to establish a connection between a connection between the welding torch and cylinder or cylinder regulator. In gas welding a dual hose line is used one for each of the gas. The advantage of double line hose is that it kept the gas lines attached. But the double line hose is not always necessary. The single hoses can also be used.
Same as the cylinders, hoses also given specific colour codes for ease of identification.
The hoses are connected with the regulators. For a better connection the hoses will be threaded.  Opposite threads will be provided for both the gases i.e. the acetylene hose will be left hand threaded and the oxygen will be right hand threaded.

3. PRESSURE REGULATORS: -

 As described above the gases in the cylinder is kept pressurized. So while we are going to use it for welding operation, the gases will reach to the welding torch. In the torch we are needed the gases at a very low pressure than in the cylinders. For this purpose we need a device to control the pressure. This device is called pressure regulator. More precisely it is called pressure reducing regulator. It maintains or adjust the pressure of the gases in the hoses as per the necessity.
When the gases reaches in the hoses, the valves are provided to maintain the appropriate flow rate of the gases for better performance. Generally the pressure gauges are provided to read the pressure and adjust it accordingly.

VALVES:-

Valves are used to maintain the flow rate of the gases in the required manner. Before we burn the fuel gases with the oxygen, the proper mixing is needed and before mixing of gases in the welding torch. A proper and calculated gas flow rate is required to be maintained. Valves are prvided to the gas welding system to solve this purpose. Valve causes the flow of gases in one directional and also avoids the back flow into the gases.

SAFETY AIDS: -