Gas Welding

Question 1

What is gas welding also known as?

Answer 1

Oxy-acetylene welding

Question 2

What type of welding process is oxy-acetylene welding?

Answer 2

This is a gas fusion welding process, melting the metals together with or without a filler rod.

Question 3

What temperature does the neutral gas mix burn at?

Answer 3

3100 degrees C

Question 4

What welding processes can be referred to as gas welding?

Answer 4

Only oxy-acetylene welding

Question 5

Explain the process for gas welding (4)

Answer 5

1. Oxygen and acetylene gases are mixed and ignited to produce a very hot flame.
2. The flame melts the joint edges and fuses the materials together.
3. A flux-coated filler rod may be used to provide additional material and flux.
4. A slag layer will form over the weld if flux is used.

Question 5

Explain the process for gas welding (4)

Answer 5

1. Oxygen and acetylene gases are mixed and ignited to produce a very hot flame.
2. The flame melts the joint edges and fuses the materials together.
3. A flux-coated filler rod may be used to provide additional material and flux.
4. A slag layer will form over the weld if flux is used.

Question 6

When drawing an oxy-acetylene welding diagram, what must be labelled and coloured?

Answer 6

Label: the base metal, torch, filler rod, hoses, regulators, oxygen cylinder, acetylene cylinder, a flashback arrestor

Colour: the oxygen cylinder is black and its hose is blue. The acetylene cylinder is marroon with a red hose.

Question 7

What does a gas regulator read?

Answer 7

It reads two things: the torch pressure and the cylinder pressure

Question 8

What is acetylene stored within the canister to make it stable?

Answer 8

acetone

Question 9

What prevents gas back-flow in gas welding?

Answer 9

Flashback arrestors protect the user and equipment from damage or explosions and back flow of gas.

Question 10

Where are the 2 gases mixed?

Answer 10

They are mixed in the mixing chamber located in the welding torch

Question 11

Gas welding pros (5)

Answer 11

1. Portable, doesn’t require an electrical power source.
2. Easy to learn and use.
3. Cheaper than other welding methods.
4. Can be used on a wide variety of metals.
5. Can be sued for a wide variety of functions: welding, cutting, brazing and soldering.

Question 12

Gas welding cons (4)

Answer 12

1. Welds can have a rough appearance, which may need machining afterwards.
2. Heat may warp some materials.
3. The flame heat may affect the properties of the metal across a wide area.
4. Not easily automatable.

Question 13

What is one major advantage of oxy-acetylene welding?

Answer 13

The gas provides the sole fuel for welding, and no external electrical input is required. This means that gas welding is ideal for site work and welding in areas where access to electricity is an issue