Q1: What is Gas Cutting?
Ans: Gas cutting is a process used to cut metal by using a flame produced from fuel gas and oxygen. The metal is heated to a high temperature and then oxygen is used to burn and remove the metal.
Q2: What is Acetylene Gas Cutting?
Ans: Acetylene gas cutting is a type of gas cutting in which acetylene gas is used as the fuel along with oxygen to produce a high-temperature flame for cutting metals.
Q3: Briefly explain the Gas Cutting Procedure.
Ans: The gas cutting procedure is as follows:
- ➔ Clean the metal surface
- ➔ Adjust the gas pressures
- ➔ Ignite the flame
- ➔ Preheat the metal
- ➔ Release oxygen to cut the metal
- ➔ Move the torch along the cutting line
Q4: What is Kerf?
Ans: Kerf is the width of the cut made in the metal during the cutting process.
Q5: What are Cutting Torches?
Ans: Cutting torches are tools used to mix fuel gas and oxygen and produce a flame for cutting metals.
Q6: Briefly explain Hand Cutting.
Ans: Hand cutting is a method in which the cutting torch is manually controlled by the operator to cut the metal.
Q7: Briefly explain Machine Cutting.
Ans: Machine cutting is a method in which the cutting torch is controlled by a machine to provide accurate and uniform cuts.
Q8: What is a Flame?
Ans: A flame is the visible hot gas produced during combustion of fuel with oxygen.
Q9: State the types of Flames.
Ans: The types of flames are as follows:
- ➔ Oxidizing Flame
- ➔ Neutral Flame
- ➔ Carburizing Flame
Q10: Briefly explain an Oxidizing Flame?
Ans: An oxidizing flame has excess oxygen. It is short and sharp and is used for cutting and welding metals like brass.
Q11: What is the temperature of an Oxidizing Flame?
Ans: The temperature of an oxidizing flame is about 3500°C.
Q12: Briefly explain a Neutral Flame?
Ans: A neutral flame has equal amounts of oxygen and fuel gas. It is commonly used for welding because it does not affect the metal properties.
Q13: What is the temperature of a Neutral Flame?
Ans: The temperature of a neutral flame is about 3200°C.
Q14: Briefly explain a Carburizing Flame?
Ans: A carburizing flame has excess fuel gas. It has a long feather and is used where carbon is required in the metal.
Q15: What is the temperature of a Carburizing Flame?
Ans: The temperature of a carburizing flame is about 3000°C.
Q16: Briefly explain Plasma Arc Cutting.
Ans: Plasma arc cutting is a process that uses a high-speed jet of ionized gas (plasma) to cut electrically conductive materials.
Q17: What are PAC Processes?
Ans: PAC processes are methods used in plasma arc cutting to cut metals using plasma and high-temperature arc.
Q18: State the gases used for Plasma Arc Cutting.
Ans: The gases used are as follows:
- ➔ Air
- ➔ Nitrogen
- ➔ Argon
- ➔ Hydrogen
Q19: State the system components of Plasma Arc Cutting.
Ans: The components are:
- ➔ Power supply
- ➔ Torch
- ➔ Gas supply
- ➔ Control unit
Q20: State the purpose of Torch in Plasma Arc Cutting.
Ans: The torch is used to generate and direct the plasma arc to cut the metal.
Q21: State the types of Torches.
Ans: The types of torches are as follows:
- ➔ Air Plasma Torch
- ➔ Oxygen-Injected Torch
- ➔ Water-Injected Torch
- ➔ Dual Gas Torch
Q22: What is Arc Starting Circuit?
Ans: Arc starting circuit is a system used to initiate the plasma arc between the electrode and the workpiece.
Q23: State some advantages of Plasma Arc Cutting.
Ans: The advantages are:
- ➔ High cutting speed
- ➔ Smooth cutting surface
- ➔ Can cut thick metals
- ➔ Less heat affected zone
Q24: Briefly explain the procedure of Plasma Arc Cutting.
Ans: The procedure is as follows:
- ➔ Start the power supply
- ➔ Supply gas to the torch
- ➔ Generate plasma arc
- ➔ Direct the arc to the metal
- ➔ Move the torch along the cutting path
Q25: Define Back Fire.
Ans: Back fire is a condition where the flame goes back into the torch with a popping sound.
Q26: State any two causes of Back Fire.
Ans: Causes are:
- ➔ Overheating of the torch
- ➔ Incorrect gas pressure
Q27: State any two types of Welding Torches.
Ans: The types are:
- ➔ Equal pressure torch
- ➔ Injector torch
Q28: Define Flashback.
Ans: Flashback is a dangerous condition in which the flame travels back into the gas hoses or cylinders.
Q29: What is the function of a Regulator?
Ans: A regulator is used to control and maintain the pressure of gas from the cylinder to a safe working level.
Q30: State the types of Regulator.
Ans: The types are:
- ➔ Single stage regulator
- ➔ Two stage regulator
Q31: Define Plasma.
Ans: Plasma is a highly ionized gas consisting of free electrons and ions, capable of conducting electricity.
