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Worksheetsmodulo 12
Total questions: 20
Worksheet time: 10mins
Which of the following can be used for oxy-fuel gas cutting?
Nitrogen
Carbon dioxide
Argon
Natural gas
What is the maximum withdrawal rate of an acetylene cylinder per hour?
10%
15%
20%
25%
Acetylene is often referred to as dissolved acetylene, but what is it dissolved in?
Carbon dioxide
Acetone
Kapok
Nitrogen
What is the approximate flame temperature of the pre-heating flames used in oxy-acetylene cutting?
2,500°C
3,000°C
3,200°C
4,000°C
Which of the following gases can be used for oxy-fuel cutting?
Nitrogen
Propane
Carbon dioxide
Argon
What is the main advantage of using a purpose built high pressure cutting torch?
Less gas is used
Safer, can cut thicker sections
Provides maximum heat output
Simpler design of nozzle
What does the term 'seat' refer to?
The number of holes in a nozzle
The position it occupies in the torch arrangement
The ledges which mate with the head of the torch
The rest on which the torch is supported during cutting
What is the most common cause of a rapid backfiring?
Pressure too high
Cutting speed too fast
Pressure too low
Using a propane nozzle
What is the approximate ignition temperature for steel?
500°
700°
900°
1000°
What is the main function of a flashback arrestor?
Extinguish all gases
Prevent a flame travelling back to the cylinder
Protect hoses from catching fire
To extinguish the flame at the nozzle
From the following list identify the functions that oxy-fuel gas cutting equipment cannot be used for?
Pre-heating
Brazing
Gouging
Rivet removal
What does the term 'stand-off distance' refer to?
The height of the torch from the material's surface
The grip held by the operator
The distance the nozzle sticks out of the torch
The gap between a guide when carrying out a straight cut
How does a nozzle for propane differ to that for acetylene?
It has three 'seats'
It is a two-part nozzle
It has more gas ports
It is longer
Why has plasma arc cutting replaced oxy-fuel in some cases?
Can cut ferrous and non-ferrous metals
Is cheaper
Is mobile
Uses less power
Why shouldn't acetylene cylinders have fittings made from 70% copper or more?
They would become toxic
They form an explosive compound
They would fracture
They would conduct electricity
What does the term 'stack' cutting refer to?
Clamping pieces together and then cutting out a profile
Dismantling of an assembly
Piercing out bolted components
Removing surplus material after casting
What does the 'transferred' arc refer to?
Coupling up of two or more machines
Transferring the arc energy from the torch into the material to initiate cutting
Polarity of the machine
A cutting technique which uses less energy
How does a nozzle designed for sheet metal differ from a conventional cutting nozzle?
It has a stepped shape which allows it to be placed at a predetermined height on the metal
It has a circular cutting ring
It has a single 'seat
It is a has a shoulder to act as a guide called a spade
What does the term exothermic mean?
Heat is absorbed
It causes oxidation of the surface
Heat is given off
Residual heat is produced
What term is given to the width of a cut in thermal cutting?
Gauge
Kerf
Dross
Profile
