p10-2 task 3

Question 1

the O-ring on the bottom of the collet cap

1. insulates the tungsten electrode from the collet cap
2. insulates to collet cap from the tungsten
3. insulates to collet cap electrically from the torch body
4. prevents the flow of shielding gas up through the top of the torch

Answer 1

d. prevents the flow of shielding gas up through the top of the torch

Question 2

the most popular type of gas cup used for GTAW torches is made from

1. ceramic material
2. metal
3. a combination of fused quartz and ceramic
4. pure copper

Answer 2

a. ceramic material

Question 3

metal particles sticking to the inside of the ceramic nozzle may

1. create an arc which is too cold
2. create arc which is too hot
3. cause gas turbulence and possible atmospheric contamination
4. impede the flow of electrons from the base metal to the tungsten electrode

Answer 3

c. cause gas turbulence and possible atmospheric contamination

Question 4

air-cooled gtaw torches are usually limited to a duchess of

1. 100 A
2. 150 A
3. 200 A
4. 250 A

Answer 4

b. 150 A

Question 5

the safe operating water pressure range for water cooled GTAW torches is

1. 70-105 kPa (10-15 psi)
2. 140-210 kPa (20-30 psi)
3. 245-280 kPa (35-40 psi)
4. 490-700 kPa (70-100 psi)

Answer 5

c. 245-280 kPa (35-40 psi)

Question 6

a tungsten electrode which is operated at a low temperature, such as in a water-cooled torch, promotes

1. the possibility of tungsten transfer across the arc
2. longer electrode life
3. shorter electrode life and less tungsten particle transfer
4. shorter electrode life and more tungsten particle transfer

Answer 6

b. longer electrode life

Question 7

water cooled gtaw torches has an advantage over air-cooled torches in that they

1. can carry higher currents
2. reduce gas flow turbulence
3. are more versatile than air-cooled torches
4. can be used on AC or DC

Answer 7

a. can carry higher currents

Question 8

match the parts of the GTAW torch shown in Figure 1 with the terms listed below

1. collet body
2. electrode collet
3. torch body
4. “O” ring
5. gas cup or nozzle
6. torch cap
7. electrode

Answer 8

1. collet body B
2. electrode collet. D
3. torch body. C
4. “O” ring F
5. gas cup or nozzle A
6. torch cap G
7. electrode E

Question 9

which component of the torch has been developed to prevent turbulence in the gas stream?

1. collet caps
2. “O” ring
3. gas lens
4. fused-quartz cups

Answer 9

d. gas lens

Question 10

which type of Cups should not be used when you weld in confined spaces?

1. alumina
2. fused-quartz
3. metal
4. ceramic

Answer 10

a. alumina