Module 9 oxy fuel cutting

Question 1

Describe the oxy fuel cutting process

Answer 1

Oxy cutting is a controlled process of rapid oxidation in which steel is heated to its kindling temperature and a high-pressure jet of pure oxygen is directed to the heated area metal exposed to the oxygen oxidizes and is blown away by the oxygen jet stream

Question 2

What two Ferris base metals cannot be cut satisfactorily with an oxy fuel cutting torch

Answer 2

Cast irons and stainless steals

Question 3

When a piece of metal is cut, it creates a cut gap called the
A) groove
B) bead
C) kerf
D) crater

Answer 3

C) kerf

Question 4

On accommodation cutting torch, the oxygen valve on the torch handle must be
A) close tightly
B) partially open
C) fully open
D) used to adjust to a neutral flame

Answer 4

C) fully open

Question 5

The rivet cutting tip is designed to
A) make suitable holes for riveted construction
B) facilitate right angle square hole cutting
C) facilitate cutting in confined spaces
D) cut off rivet and bolt heads without disturbing the parent metal

Answer 5

D) cut off rivet and bolt heads without disturbing the parent metal

Question 6

Which cutting tip has preheat orifices in a smaller pitch circle around the cutting orifice
A) standard cutting tip
B) high speed cutting tip
C) gouging tip
D) rivet cutting tip

Answer 6

B) high speed cutting tip

Question 7

The larger the orifices on a cutting tip:
A) less gas you burn
B) greater the heat loss
C) faster you cut
D) thicker the plate that you can cut

Answer 7

D) thicker the plate that you can cut

Question 8

Which metals can you cut easily using the oxy fuel cutting process?
A) cast irons
B) mild steels
C) stainless steel
D) nickel alloys

Answer 8

B) mild steels

Question 9

Which oxy fuel torch design has the mixer chamber inside one of the tubes leading to the torch head
A) tip mixing
B) high-speed
C) pre-mixing
D) oxygen lance

Answer 9

C) pre-mixing

Question 10

Explain why you cannot cut non-Ferris metals using an oxy fuel torch

Answer 10

Unlike steel non-Ferris metals will not oxidize or burn progressively

Question 11

List three methods used for starting a cut on round stock

Answer 11

1. Use a chisel to make the surface.
2. Drill into the surface.
3. Apply a bead of arc weld

Question 12

List three types of control systems use for mechanized oxyfuel cutting

Answer 12

1. Machine tracer guided.
2. Magnetic tracer guided.
3. Electronic tracer guided.

Question 13

Templates for magnetic tracers are made of

Answer 13

Steel

Question 14

Photo electric cells and computer controls are used with ______ tracer guided cutting machines
A) manual
B) machine
C) magnetic
D) electronic

Answer 14

D) electronic

Question 15

When preheating for flame cutting the metal should be heated until it reaches its
A) liquid state
B) bright yellow colour
C) kindling point
D) transition temperature

Answer 15

C) kindling point

Question 16

When the cut is rough and the slag accumulates on the bottom edge, the likely cause is
A) using propane fuel gas
B) using oxygen that is only 99.5% pure
C) using a dirty tip
D) using a cutting attachment type torch

Answer 16

C) using a dirty tip

Question 17

When piercing holes in a plate you should
A) press, the cutting lever sharply to start the cut
B) allow the preheat cones to touch the material surface
C) raise the oxygen pressure by 25%
D) raise the tip when the cutting lever is depressed

Answer 17

D) raise the tip when the cutting lever is depressed

Question 18

What is likely to happen if the cutting travel speed is too fast
A) productivity increases in your employer is very impressed
B) slag bubbles to the surface and the cutting action eventually stops
C) the tip overheats and begins to backfire
D) clean slag free cut is produced

Answer 18

B) slag bubbles to the surface and the cutting action eventually stops

Question 19

What is likely the problem if the curve edges are melting back together behind the cut
A) the tip is too large for the material thickness
B) impurities are in the fuel gas
C) the steel has too high carbon content
D) you are running low on fuel gas

Answer 19

A) the tip is too large for the material thickness

Question 20

If a shop were to switch from acetylene to propane gas for cutting, it would be necessary to
A) purchase all new torches
B) install special fuel, gas regulators
C) check with the manufacturer to determine if the equipment is compatible
D) change to larger size hoses

Answer 20

C) check with the manufacturer to determine if the equipment is compatible

Question 21

You can determine a good quality cut by
A) inspecting the kerf lines
B) asking the foreman
C) the amount of welding experience the operator has
D) the amount of oxygen and acetylene consumed

Answer 21

A) inspecting the kerf lines

Question 22

Kerf drag lines on a properly performed shape cut should be
A) irregular in profile
B) curved to match the shape
C) perpendicular to the plate surface
D) horizontally inclined

Answer 22

C) perpendicular to the plate surface

Question 23

If you noticed the preheat flames changing from neutral to carbonizing during the cutting process, the most most likely caused would be that the
A) oxygen cylinder is nearly empty
B) acetylene consumption is too high
C) acetylene cylinder is nearly empty
D) tip is dirty and requires cleaning

Answer 23

A) oxygen cylinder is nearly empty

Question 24

What tools can you use to lay out a structural shape?
A) contour marker
B) hammer and centre punch
C) square and level
D) combination square
E) all of the above

Answer 24

E) all of the above

Question 25

A skid unit requires 2S shapes to be welded together to create a 90° angle. How can you cut the S shapes to create the required fit up?
A) but the flanges together and weld the gaps
B) cope, one beam to fit inside the other
C) an angle of 45° on each shape and fit together
D) both B&C
E) all of the above

Answer 25

D) both B&C

Question 26

When cutting structural shapes, it is important to remember to watch your torch angle a torch angle that is off, can cause a structural shape to be cut incorrectly, which could result in a scrapped piece
True or false

Answer 26

True