What is Gas Welding?
Gas welding is a type of liquid state welding process in which fuel gases burns to generate heat. This heat is further used to melt interface surfaces of welding plates which are held together to form a joint. In this process, mostly oxy-acetylene gas is used as fuel gas.
Principle:
Gas welding is a most important type of welding process. It is done by burning of fuel gases with the help of oxygen which forms a concentrated flame of high temperature. This flame directly strikes the weld area and melts the weld surface and filler material. The melted part of welding plates diffused in one another and create a weld joint after cooling.
Equipment:
Welding Torch:
Welding torches are most important part of gas welding. Both the fuel gas and oxygen at suitable pressure fed through hoses to the welding torch. There are valves for each gas witch control the flow of gases inside the torch. Both gases mixed there and form a flammable mixture. These gases ignite to burn at the nozzle. The fire flame flow through nozzle and strikes at welding plates.
Oxygen Cylinder:
For proper burning of fuel, appropriate amount of oxygen required. This oxygen supplied by a oxygen cylinder
Fuel Gas Cylinder:
Gas cylinder is filled either by oxy acetylene gas, hydrogen gas, natural gas or other flammable gas. The fuel gas selection is depends on the welding material.
Pressure regulator:
Both oxygen and fuel gases are filled in cylinder at high pressure. These gases cannot use at this high pressure for welding work so a pressure regulator is used between flow. It supplies oxygen at pressure about 70 – 130 KN / M2 and gas at 7 – 103 KN / M2 to the welding torch.
Goggles and Gloves:
These are use for safety purpose of welder. It protects eyes and hand from radiation and flame of fire.
Working:
- In this process all the equipment are connected carefully. The gas cylinder and oxygen cylinder connected to the welding torch through pressure regulators.
- Now the regulate pressure of gas and oxygen supplied to the torch where they properly mixed. The flame is ignited by a striker.
- Now the flame is controlled through valves situated in welding torch. The flame is set at natural flame or carburizing flame or oxidizing flame according to the welding condition.
- Now the welding torch moved along the line where joint to be created.
- This will melt the interface part and join them permanently.
Application:
- Gas welding mostly used in fabrication of sheet metal.
- It is widely used in automobile and aircraft industries.
