Atl Oxy-Fuel Welding And Cutting

Front 1

How is acetylene gas produced?

Back 1

By the reaction of calcium carbide and water or from natural gas and petroleum

Front 2

Pressurized Oxygen is dangerous in contact with what materials?

Back 2

Oil
Grease
Tarry Substances
Common Solvents
Many Plastics

Front 3

What materials shouldn't be used with acetylene and why?

Back 3

Copper
Copper alloys containing more than 70% copper
Silver
Silver alloys containing moe than 43% silver

They can produce explosive compounds such as Copper acetylide

Front 4

How should compressed gas cylinders be safely stored?

Back 4

In a well ventilated flame-proof room
Protected from the weather
Away from sources of heat
Away from grease or oil
Away from high current electrical equipment
Secured in an upright position
Oxygen separate from combustible gases - 3m apart or divided by a fire wall at least 22cm thick (30 mins barrier)
LPG separate from any other compressed gas cylinders
Full and empty cylinders apart
Not with other products, particularly oil, paint or corrosive liquids and chemicals.

Front 5

What results from compressed Oxygen being used too quickly?

Back 5

A rapid drop of pressure and temperature in the cylinder
Cylinder valve may freeze

When a high rate of consumption is needed, manifold multiple cylinders

Front 6

What are the two components of a Flashback Arrestor?

Back 6

Flame Front - filters/extinguishes the flame

Pressure Valve - cuts off the gas supply

Front 7

When storing gas cylinders, what should the temperature not exceed?

Back 7

52 degrees C

Front 8

When transporting compressed gas cylinders, what should the driver have with him?

Back 8

Gas manufacturer's information card
Gas data sheets
Gas safety sheets

Front 9

Identify different gas welding processes

Back 9

Oxy-Acetylene
Oxy-Propane
Oxy-Hydrogen

Air-Acetylene
Air-Propane

Front 10

What is the correct temperature for a neutral oxy-acetylene flame?

Back 10

3200ºc

Front 11

What is the numerical code for Oxy-fuel welding?

Back 11

31

Front 12

What is the numerical code for Oxy-acetylene welding?

Back 12

311

Front 13

What else is inside an acetylene cylinder?

Back 13

Liquid acetone - the acetylene is dissolved in this which stabilises it under pressure

A porous mass - Agamassan, which keeps the solution from separating

Front 14

What is the maximum amount of Acetylene that should be 'drawn off' from a cylinder?

Back 14

20% per hr

Front 15

What can rapid drawing off of acetylene cause?

Back 15

The acetylene to boil out of the acetone, bringing some acetone with it.
This can contaminate the weld and damage equipment

Front 16

When using acetylene, what is the maximum pressure that should be used?

Back 16

0.62 bar

Front 17

How is Oxygen gas produced?

Back 17

From the distillation of air, which contains up to 21% oxygen

Front 18

1 lb per sq inch = how many Bar?

Back 18

Approximately 0.07

Front 19

1 Bar = how many lb per sq inch?

Back 19

14.5

Front 20

what is the body of a regulator made from and why?

Back 20

Brass

Withstands rough conditions
Dissipates heat quickly caused by fast opening of the cylinder valve
Will withstand 3 x cylinder pressure

Front 21

What does a Safety valve on a regulator do?

Back 21

Discharges pressure very quickly then reseals when correct operation pressure is restored

Front 22

What pressure are oxygen regulators capable of working with?

Back 22

230 bar

Front 23

What are oxyacetylene hoses made from?

Back 23

Synthetic rubber (neoprene lining and cover) with three layers of rubberised canvas reinforcement

Front 24

What is the maximum working pressure for most oxy-acetylene hoses?

Back 24

20 bar

Front 25

What is the function of a non-return valve?

Back 25

They are fitted to the torch end of gas hoses to prevent back feeding of gases

Front 26

An Oxy-acetylene torch is made up of what components?

Back 26

Shank with control valves, mixer and nozzle

Front 27

What does the number stamped on welding nozzles indicate?

Back 27

The hole size
The amount of gas (in psi) that will be used per hour using a steady neutral flame

Front 28

What is this?

Back 28

A Gas Economiser

Front 29

What pressure should gases be set at when welding up to 3.2mm mild steel?

Back 29

0.14 bar (2lb/sq inch)

Front 30

What pressure should gases be set at when welding 4mm mild steel?

Back 30

0.21 bar (3lb/sq inch)

Front 31

What pressure should gases be set at when welding 5-6.5mm mild steel?

Back 31

0.28 bar (4lb/sq inch)

Front 32

What kind of flame is this and what is it used for?

Back 32

Carburising flame

Used for Hard-Surfacing

Front 33

What kind of flame is this and what is it used for?

Back 33

Neutral flame

Used for welding

Front 34

What kind of flame is this and what is it used for?

Back 34

Oxidising Flame

Slightly oxidising flame used for brazing or braze welding

Front 35

What is the 'leftward technique' used for?

Back 35

Welding steel plate up to 4.5mm thick and for welding non-ferrous metals

Front 36

What slope angle should the torch and filler rod be held at when using the leftward technique?

Back 36

Torch - 60-70º

Filler Rod - 30-40º

Front 37

How far from the base material should the torch tip be when oxyacetylene welding?

Back 37

3-5mm from inner cone tip to material

Front 38

How should the filler rod be fed when oxyacetylene welding?

Back 38

At regular intervals into the weld pool, not the flame

Front 39

What is the 'rightward technique' used for?

Back 39

Steel plate over 4.5mm thick

Front 40

What slope angle should the torch and filler rod be held at when using the rightward technique?

Back 40

Torch - 40-50º

Filler Rod - 30-40º

Front 41

How should 'Stop Start Technique' be used?

Back 41

Reheat the weld approximately 12mm back from the point you stopped
Use a steeper angle - 80º until you reach where filler material needs adding, then reduce to 60-70º

Front 42

How does 'blowback' occur

Back 42

When the nozzle is too close to the material, molten metal attaches to it causing a build up in gas pressure leading to a small explosion

Front 43

What part of the weld is the Root?

Back 43

The furthermost point of Fusion in a welded joint - the deepest part of the weld

Front 44

What part of the weld is the Root Face?

Back 44

A section of the prepared weld edge (at the bottom), that is at a 90º angle.

Front 45

Identify fuel gases used for flame cutting

Back 45

Acetylene

Propane

Hydrogen

Methane (natural gas)

MAPP gas

LPG (Propylene)

Front 46

What is the maximum depth of cut advised when using a combination torch

Back 46

100mm

Front 47

What is the ignition temperature for steel, and how is it identified?

Back 47

900-950ºc

Cherry red colour

Front 48

What are the two flame gouging techniques?

Back 48

Progressive gouging - where a continuous groove is gouged

Spot gouging - where small, often deep areas are removed

Front 49

What angles should a gouging torch be held at when gouging from an edge?

Back 49

Pre-heat angle 25-30º

Gouging angle 5-10º

Front 50

What angles should a gouging torch be held at when gouging not from an edge?

Back 50

Pre-heat angle 35-40º

Gouging angle 5-15º

Front 51

What are the different types of cutting torches available?

Back 51

Combined Torch

Hand Cutter

Nozzle Mix Cutter

Premix Cutter

Front 52

Describe a Combined Torch

Back 52

Can be adapted for cutting, heating or welding

Front 53

Describe a Hand Cutter

Back 53

Available in a variety of lengths and used for cutting thicker section, so the operator is further away from the heat.

Front 54

Describe a Nozzle Mix Cutter

Back 54

Gases don't mix until they reach the nozzle, reducing the force of the igition explosion and the chance of flashback

Front 55

Describe a Premix/Injection Cutter

Back 55

Mixes the gases in the head, making the head larger and heavier than other torches

OR

Mixes the gases in the torch body (gas delivery tubes)

Injector torches have the advantage of being able to use the higher pressure of oxygen to pull the fuel into the torch. This allows the torch to be used at low fuel gas pressures or with large pressure drops such as those experienced through long hose lengths.

Front 56

Describe the appearance of a good oxyfuel cut

Back 56

Sharp top and bottom edges

Vertical drag lines

No adhering dross

Square face

Light, easily removed scale

Front 57

Describe the appearance of an oxyfuel cut where cutting speed has been too fast

Back 57

Top edge not sharp

Rounded bottom edge, which may not be completely severed

Drag lines uneven, sloping backwards

Front 58

Describe the appearance of an oxyfuel cut where cutting speed has been too slow

Back 58

Rounded and melted top edge

Bottom edge rough

Dross on bottom edge difficut to remove

Lower part of cut face irregularly gouged

Heavy scale on cut face

Front 59

Describe the appearance of an oxyfuel cut where the nozzle has been held too high

Back 59

Excessive melting of top edge

Undercut at top of cut face

Course draglines at bottom of cut face

Front 60

Describe the appearance of an oxyfuel cut where cutting speed has been irregular

Back 60

Wavy cut edge

Uneven drag lines

Front 61

Describe the appearance of an oxyfuel cut where preheating flame has been too high

Back 61

Rounded top edge

Irregular cut edge

Melted metal falling into kerf

Excessive dross adhering to bottom edge

Front 62

Describe the appearance of an oxyfuel cut where preheating flame has been too low

Back 62

Bad gouging of lower part of cut face

Cutting speed slow

Front 63

Describe this cut

Back 63

Cut too fast

Front 64

Describe this cut

Back 64

Oxygen too high

Front 65

Describe this cut

Back 65

Good cut

Front 66

Describe this cut

Back 66

Nozzle too high