_____ is used for mixing oxygen and acetylene in gas welding processes.

Explanation:

Welding torch:

• A welding torch is a critical tool used in gas welding processes to mix oxygen and acetylene gases in the appropriate proportions for combustion. This mixture, when ignited, produces a high-temperature flame, which is used to melt and join materials such as metals. The welding torch ensures precise control over the gas flow, allowing the welder to achieve the desired flame characteristics for effective welding.
• In gas welding, oxygen and acetylene are stored separately in high-pressure cylinders. The welding torch has two inlets—one for oxygen and one for acetylene. These gases pass through individual control valves, allowing the welder to adjust their flow rates. Inside the welding torch, the gases mix in a mixing chamber before exiting through the torch nozzle, where they are ignited to produce the flame. By adjusting the proportions of oxygen and acetylene, the welder can control the flame type (neutral, oxidizing, or carburizing) to suit the specific welding application.

Working Principle of a Welding Torch:

• Gas Supply: Oxygen and acetylene are supplied from their respective cylinders through hoses to the welding torch.
• Mixing Chamber: Inside the welding torch, the gases are mixed in a controlled manner to achieve the desired ratio.
• Nozzle: The mixed gases are expelled through the nozzle of the torch, where they are ignited using a spark lighter or similar tool.
• Flame Control: The welder adjusts the control valves to regulate the gas flow, ensuring a stable and efficient flame.

The welding torch is designed to handle the high temperatures and pressures associated with gas welding. It is ergonomically designed to provide comfort and precision to the welder, making it an indispensable tool in welding operations.

Importance of Proper Gas Mixing:

The correct mixture of oxygen and acetylene is essential for achieving the desired flame characteristics:

• Neutral Flame: The oxygen and acetylene are mixed in equal proportions, producing a balanced flame with a well-defined inner cone. This flame is suitable for most welding applications.
• Oxidizing Flame: A higher proportion of oxygen results in an oxidizing flame, which is useful for specific applications like brazing but can cause oxidation in certain metals.
• Carburizing Flame: A higher proportion of acetylene results in a carburizing flame, which is used for specific tasks requiring additional carbon in the weld.