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WorksheetsMaintenace welding 2
Total questions: 36
Worksheet time: 18mins
The red hose on an oxyacetylene regulator connects to the _____
Oxygen
Acetylene
Either regulator, it doesn't matter
Neither regulator, a red hose is never used in oxyacetylene welding
What is the purpose of having Reverse-flow check valves at either the torch inlets or regulator outlets?
To prevent mixing oxygen and acetylene from flowing back to the regulators
To keep the hoses from working loose
To reduce the gas pressure
To prevent damage to the torch or regulator threads
What should NOT be used on an oxyacetylene fitting?
Soapy solution
lubricant
Water
All are okay
Acetylene and oxygen hoses should be purged (a) seconds for every 25 feet of hose
Acetylene has a maximum safe working pressure of (a) psi
When lighting an oxyacetylene torch, always open and _____ first
light the oxygen
light the acetylene
light both at the same time
lighting order does not matter.
Gas cylinders should be
stored upright
stored separately for fuel and oxygen stored with valve closed when not in use
All of the above
An oxyacetylene torch should always be lit using a(n)
match
friction striker
cigarette lighter
piezoelectric igniter
An oxyacetylene cutting leak can be located by
Sniffing around the hoses
Feeling the hose for gas release
Using a soap solution looking for bubbles
Noticing a light blue flame
Before connecting a regulator, valves should be cleared by
Wiping them off
Cracking the valves momentarily
Inserting a valve cleaner into the valve and rotating it clockwise
Using a wire brush
Check for gas leaks around the regulator using a(n)
lit match
small test
soap bubble solution
pressure gauge
An acetylene flame burns at
6,000 °C (10,834 °F)
1,925 °C (3,500 °F)
3,500 °C (6,000 °F)
28,000 °C (50,000 °F)
Acetylene cylinders are painted
to identify the gas.
green
black
red
acetylene cylinders are not color coded
The dangerous condition that occurs in oxyacetylene welding where the flame spreads back down the hoses is called
Burn-back
Flame propagation
Flashback
Arc burn
Attached to the cylinders are set to provide proper gas flow.
flow meters
regulators
Flashback arrestors
valves
Goggles for oxyacetylene cutting should be shade
3 to 5
6 to 8
9 to 10
11 to 13
The first step in disassembling a plasma torch is to
remove the shield
remove the tip
remove the electrode
disconnect the power
Most plasma arc torches have a switch that
senses when the arc has started
closes when all parts are installed correctly
detects proper gas flow
opens if the torch gets too hot
Prepare metal for plasma arc cutting by
removing any rust
grinding the metal until smooth
squaring the edge where the cut will begin
removing any grease, cladding, or paint
The plasma arc current setting is determined by
the thickness of the metal
type of metal to be cut
Cutting speed
type of cut to be made
_____ is the most common gas used in plasma arc cutting.
Shop air
Dry nitrogen
Carbon dioxide
Hydrogen
Plasma arc cutting is a fast, accurate method of cutting
only non-ferrous metal
only ferrous metal
any metal that conducts electricity
plastics and ceramic
_____ in a plasma arc torch separates the gas into two streams, one for ionization and the other for shielding
swirl ring
torch head
electrode
shield
Pressing the plasma arc torch trigger produces an arc that forces the gas to _____ state
static
gaseous
plasma
dynamic
Eye protection for plasma cutting should be shade
1 to 3
4 to 8
9 to 10
11 to 13
Toxic fumes can be created by
ionizing the plasma gas
burning slag in the kerf
cutting non-ferrous metal
coatings or paint on the metal
The most common oxyacetylene cut is a(n)
bevel
piercing
edge
center
A(n) _____ cut is one that does not start at the edge of the metal.
bevel
piercing
edge
center
Typically, a bevel cut angle is _____ degrees when two pieces of metal are to be butt welded together.
37-1/2
22-1/2
45
90
The cut face of a good oxyacetylene cut should
have angled drag lines randomly spaced
have a rounded surface
have noticeable undercutting on the bottom
be square to the surface
In general, the quality of an oxyacetylene cut increases as
the speed decreases
the thickness decreases
the speed increases
the temperature increases
A piercing cut takes longer to start because
the cut does not start at the edge
the arc has a greater distance to travel before contacting the metal
the metal must be melted all the way through before it is blown away
holding the torch at an angle weakens the arc
An edge cut should begin with
the torch held at a 45-degree angle
the torch 3 to 6 mm (1/8 to 1/4 in.) from the workpiece
the shield near the center of the workpiece
the torch against a straight edge
Typically, a bevel cut of _____ degrees is commonly used in metal fabrication.
37-1/2
22-1/2 to 45
60
90
When shutting down a plasma arc cutter, turn the current control to
mid-range to facilitate a faster start up the next time the cutter is used
full amperage because that is the most commonly used setting
minimum to avoid electrical shock
setting doesn't matter because it will need to be set for the next job
Plasma arc cuts have a good and bad side depending on the kerf cut angle. An acceptable kerf angle is degrees.
0 to 1
1 to 3
4 to 5
6 to 10
