Question 1

Explain why the heat of the arc, which is much higher than the melting point of tungsten, does not actually melt the tungsten electrode.

Accepted Answer

The thermal conductivity of tungsten and...

Question 2

How must tube- and ball-type flowmeters be mounted?

Accepted Answer

A)   Horizontally
B)   On a solid surface
C)   Vertically
D)   Between 5 ft and 5.5 feet above the floorE) B) and C)
F) A) and D)

Question 3

Explain how tungsten electrodes are produced.

Accepted Answer

Tungsten is produced mainly by reduction...

Question 4

Tungsten electrodes that contain elements such as lanthanum or yttrium are referred to as _____.

Accepted Answer

A)   alternating current only electrodes
B)   low-alloy tungsten electrodes
C)   low-hydrogen tungstens
D)   rare earth tungstensE) A) and B)
F) None of the above

Question 5

____________________, when added in percentages of up to 0.6 percent to tungsten, improves its current-carrying capacity.

Accepted Answer

The answer of ____________________, when added in percentages of up...

Question 6

Which of the following is a way to minimize erosion of the tungsten electrode?

Accepted Answer

A)   Use as high a current as possible.
B)   Use an air-cooled torch.
C)   Use as small a size of tungsten electrode as possible.
D)   Use DCEN current.E) B) and D)
F) A) and B)

Question 7

What is the most likely explanation for why DCEP has a cleaning action?

Accepted Answer

There are many theories as to why DCEP h...

Question 8

What is the purpose of a gas lens?

Accepted Answer

A)   It helps to see the molten weld pool by magnifying it.
B)   It filters out most of the harmful UV and some of the IR light.
C)   It reduces the turbulence in the shielding gas.
D)   It filters out dust and dirt that might be in the shielding gas due to a dirty shielding gas hose.E) B) and C)
F) A) and C)

Question 9

Flowmeters measure the flow rate of a shielding gas in __________units.

Accepted Answer

A)   CFH or L/min
B)   BTU or mm/sec
C)   GPH or K/min
D)   PSI or kPaE) A) and B)
F) C) and D)

Question 10

Adding ____ has the same effect on the electrode characteristic as thorium, but it is not radioactive.

Accepted Answer

A)   pure tungsten
B)   cerium
C)   zirconium
D)   lanthanumE) None of the above
F) All of the above

Question 11

The ____ protects the molten weld pool, the filler rod, and the tungsten electrode as they cool to a temperature at which they will not oxidize rapidly.

Accepted Answer

A)   preflow period
B)   postflow period
C)   shielding gas
D)   nozzleE) A) and C)
F) B) and C)

Question 12

The improved electron emission of the ____ allows it to carry approximately 20% more current than pure tungsten.

Accepted Answer

A)   thoriated tungsten
B)   cerium tungsten
C)   zirconium tungsten
D)   lanthanum tungstenE) C) and D)
F) B) and D)

Question 13

____ electrodes have a current-carrying capacity similar to that of pure tungsten, and may be used for both AC and DC welding currents.

Accepted Answer

A)   Thoriated tungsten
B)   Cerium tungsten
C)   Zirconium tungsten
D)   Lanthanum tungstenE) All of the above
F) B) and C)

Question 14

When the shielding gas flow rate is high, air is drawn into the gas envelope by a(n) ____________________ effect around the edge of the nozzle.

Accepted Answer

The answer of When the shielding gas flow rate is...

Question 15

The squarewave provides the welder with a current that allows the molten weld pool to _______________.

Accepted Answer

A)   have both deeper penetration and faster solidification
B)   have more gas coverage of the weld at a slower flow rate
C)   be cleaner and reduces the need to clean all of the oxides off of the underside of the weld joint
D)   flow freely onto the base metal with minimum fusion for thinner metalsE) C) and D)
F) B) and D)

Question 16

With ____, penetration and bead profile are sensitive to arc length, and the long arcs needed for feeding filler wires are more difficult to control.

Accepted Answer

A)   helium
B)   nitrogen
C)   hydrogen
D)   argonE) All of the above
F) B) and D)

Question 17

In GTAW, the arc temperature is around ____ Fahrenheit.

Accepted Answer

A)   3,000 °
B)   6,000 °
C)   11,000 °
D)   17,000 °E) A) and D)
F) A) and B)

Question 18

____________________ is a by-product of the natural gas industry that is removed from natural gas as the gas undergoes separation for purification or refinement.

Accepted Answer

The answer of ____________________ is a by-product of the natural...

Question 19

Why is an inert shielding gas required for GTA welding?

Accepted Answer

A)   To keep the air away from the hot tungsten and molten weld metal
B)   To help remove the welding fumes to make it easier to see the weld pool
C)   To help reduce the UV light that can cause skin burns
D)   All of the aboveE) A) and C)
F) A) and B)

Question 20

____________________ is the time during which the gas continues flowing after the welding current has stopped.

Accepted Answer

The answer of ____________________ is the time during which the...

Exam 16: Gas Tungsten Arc Welding Equipment, Setup, and Operation

____________________, when added in percentages of up to 0.6 percent to tungsten, improves its current-carrying capacity.

Correct AnswerverifiedShow Answer

The squarewave provides the welder with a current that allows the molten weld pool to _______________.

Correct AnswerverifiedShow Answer

Tungsten electrodes that contain elements such as lanthanum or yttrium are referred to as _____.

Correct AnswerverifiedShow Answer

What is the most likely explanation for why DCEP has a cleaning action?

Correct AnswerverifiedThere are many theories as to why DCEP h...View AnswerShow Answer

Explain how tungsten electrodes are produced.

Correct AnswerverifiedTungsten is produced mainly by reduction...View AnswerShow Answer

Adding ____ has the same effect on the electrode characteristic as thorium, but it is not radioactive.

Correct AnswerverifiedShow Answer

____________________ is the time during which the gas continues flowing after the welding current has stopped.

Correct AnswerverifiedShow Answer

____ electrodes have a current-carrying capacity similar to that of pure tungsten, and may be used for both AC and DC welding currents.

Correct AnswerverifiedShow Answer

____________________ is a by-product of the natural gas industry that is removed from natural gas as the gas undergoes separation for purification or refinement.

Correct AnswerverifiedShow Answer

The ____ protects the molten weld pool, the filler rod, and the tungsten electrode as they cool to a temperature at which they will not oxidize rapidly.

Correct AnswerverifiedShow Answer

Explain why the heat of the arc, which is much higher than the melting point of tungsten, does not actually melt the tungsten electrode.

Correct AnswerverifiedThe thermal conductivity of tungsten and...View AnswerShow Answer

The improved electron emission of the ____ allows it to carry approximately 20% more current than pure tungsten.

Correct AnswerverifiedShow Answer

When the shielding gas flow rate is high, air is drawn into the gas envelope by a(n) ____________________ effect around the edge of the nozzle.

Correct AnswerverifiedShow Answer

Flowmeters measure the flow rate of a shielding gas in __________units.

Correct AnswerverifiedShow Answer

Why is an inert shielding gas required for GTA welding?

Correct AnswerverifiedShow Answer

Which of the following is a way to minimize erosion of the tungsten electrode?

Correct AnswerverifiedShow Answer

How must tube- and ball-type flowmeters be mounted?

Correct AnswerverifiedShow Answer

In GTAW, the arc temperature is around ____ Fahrenheit.

Correct AnswerverifiedShow Answer

With ____, penetration and bead profile are sensitive to arc length, and the long arcs needed for feeding filler wires are more difficult to control.

Correct AnswerverifiedShow Answer

What is the purpose of a gas lens?

Correct AnswerverifiedShow Answer

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There are many theories as to why DCEP h...
View Answer

Correct Answer
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Tungsten is produced mainly by reduction...
View Answer

Correct Answer
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Correct Answer
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The thermal conductivity of tungsten and...
View Answer

Correct Answer
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Correct Answer
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