Viva/ Interview Questions and Answers on Gas Welding
What is gas welding?
Gas welding is a welding process that uses a flame produced by burning a mixture of gases (usually acetylene and oxygen) to heat the metal to be welded. The metal then melts and fuses together to form a weld.
What are the advantages of gas welding over other welding methods?
- Gas welding is relatively cheap compared to other welding methods.
- It is portable, making it suitable for on-site welding jobs.
- It does not require any electrical power, making it ideal for use in remote locations.
- The process is relatively simple and does not require extensive training.
What gases are commonly used in gas welding?
Acetylene and oxygen are the most commonly used gases in gas welding.
What are the safety precautions to be taken while gas welding?
- Make sure to use the right type of gas cylinder for the job.
- Make sure that the cylinder is secured and upright at all times.
- Use the correct regulator for the gas cylinder you are using.
- Use a flashback arrestor to prevent gas from flowing back into the cylinder.
- Wear protective clothing, including gloves, eye protection, and a welding helmet.
What is the difference between welding and brazing?
Welding and brazing are two different processes that involve joining two pieces of metal together. Welding involves heating the metal to its melting point and then fusing it together. Brazing, on the other hand, involves heating the metal to a temperature below its melting point and using a filler material to bond the two pieces together.
What are the types of gas welding?
The two main types of gas welding are oxy-acetylene welding and torch brazing.
What is the process of oxy-acetylene welding?
The process of oxy-acetylene welding involves using a flame produced by burning a mixture of oxygen and acetylene to heat the metal to be welded. The metal then melts and fuses together to form a weld.
What is the process of torch brazing?
Torch brazing is similar to oxy-acetylene welding, but the metal is heated to a temperature below its melting point. A filler material is then used to bond the two pieces together.
What is the difference between welding and soldering?
Welding and soldering are two different processes used to join two pieces of metal together. Welding involves heating the metal to its melting point, while soldering involves heating the metal to a lower temperature below its melting point.
What is the role of the regulator in gas welding?
The regulator is used to control the pressure of the gases being used in the welding process. It is responsible for maintaining a consistent pressure in the gas line, which helps to ensure a stable and consistent flame during welding.
What is the importance of using the right type of gas cylinder?
Using the right type of gas cylinder is important because each type of gas cylinder is designed to hold a specific type of gas. If the wrong type of cylinder is used, it could cause the cylinder to fail, leading to a dangerous situation.
What is a flashback arrestor and why is it important to use one while gas welding?
A flashback arrestor is a safety device that is used to prevent gas from flowing back into the gas cylinder. If gas were to flow back into the cylinder, it could cause the cylinder to explode. It is important to use a flashback arrestor to ensure the safety of the person welding.
What is the importance of wearing protective clothing while gas welding?
Wearing protective clothing while gas welding is important because the welding process generates intense heat and bright light, which can cause injury to the skin, eyes, and respiratory system. Protective clothing, including gloves, eye protection, and a welding helmet, help to minimize the risk of injury.
What is the difference between TIG and MIG welding?
TIG and MIG welding are two different types of welding that use different methods to heat the metal and create the weld. TIG welding uses a tungsten electrode to heat the metal, while MIG welding uses a consumable wire that is fed into the weld pool.
What is the role of filler metal in gas welding?
Filler metal is a material used to add strength and stability to the weld. It is used in brazing and some forms of welding to reinforce the bond between the two pieces of metal being joined.
What is the importance of preheating the metal before welding?
Preheating the metal before welding helps to reduce the thermal shock that can occur during welding. It also helps to prevent warping and cracking of the metal.
What is the importance of proper gas flow during gas welding?
Proper gas flow during gas welding is important because it affects the stability and quality of the flame. If the gas flow is too high, the flame will be too hot, which can cause the metal to melt too quickly. If the gas flow is too low, the flame will be too cool, which can prevent the metal from melting.
What are the different types of welding joints?
There are several different types of welding joints, including butt joints, lap joints, T-joints, and corner joints. Each type of joint is used for specific applications and requires different welding techniques.
What is the importance of proper welding technique?
Proper welding technique is important because it affects the quality and strength of the weld. If the welding technique is incorrect, it can result in weak or porous welds, which can lead to failure of the structure.
What is the difference between oxy-acetylene and oxy-fuel welding?
Oxy-acetylene welding and oxy-fuel welding are two terms that are often used interchangeably to refer to the same process of welding with a flame produced by the combustion of oxygen and acetylene gases.
What is the difference between shielding gas and backing gas in welding?
Shielding gas is a gas used to protect the weld from contamination during the welding process, while backing gas is a gas used to support the weld from the back side and prevent oxidation.
What are the most common gases used in gas welding?
The most common gases used in gas welding include acetylene, propane, and natural gas.
What is the purpose of using a flow meter in gas welding?
A flow meter is used to measure the flow rate of the gases being used in the welding process. It helps to ensure that the correct amount of gas is being used, which is important for maintaining a stable flame and producing high-quality welds.
What is the difference between brazing and soldering?
Brazing and soldering are both processes used to join two pieces of metal together, but there is a difference in the temperature used and the type of filler metal used. Brazing involves heating the metal to a higher temperature than soldering, and brazing filler metal has a higher melting point than soldering filler metal.
What is the role of the welding torch in gas welding?
The welding torch is the tool used to deliver the heat and the shielding gas to the area being welded. It consists of a handle, a nozzle, and a tip that are used to control the flame.
What is the importance of using the correct welding rod in gas welding?
Using the correct welding rod is important because different welding rods are designed for different types of metal and welding processes. The correct welding rod will provide the best results in terms of strength, quality, and consistency of the weld.
What is the role of the filler rod in gas welding?
The filler rod is a material used to add strength and stability to the weld. It is melted and added to the weld pool to reinforce the bond between the two pieces of metal being joined.
What is the difference between AC and DC welding?
AC and DC welding refer to the type of current used in the welding process. AC welding uses alternating current, while DC welding uses direct current. The type of current used affects the quality and consistency of the weld.
What is the importance of pre-cleaning the metal before welding?
Pre-cleaning the metal before welding is important because it removes any contaminants that could negatively impact the quality and strength of the weld. Contaminants such as rust, oil, and grease can cause porosity and weakness in the weld.