GTAW/COMPUTERIZED LAYOUTS AND PLASMA

Question 1

What are the 4 safety considerations with gtaw

Answer 1

Electrical hazards, eye protection, protective clothing, ventilation

Question 2

What type of arc is emitted from GTAW

Answer 2

Ultraviolet infrared rays

Question 3

When is the most intense ultraviolet radiant energy produced

Answer 3

When argon shielding gas is used and when aluminum or stainless is being welded

Question 4

Which gasses displace air and cause asphyxiation from low oxygen

Answer 4

Argon and helium

Question 5

What does atmospheric oxygen react with to produce significant quantities of ozone gas (toxic)

Answer 5

Intense ultravilot light

Question 6

Why do cylinder and regulator connections vary in sizes

Answer 6

To eliminate the possibility of interchanging regulators to cylinders

Question 7

How much residual pressure should remain in a cylinder to avoid atmospheric contamination of its interior

Answer 7

25 psi

Question 8

How is the electrode arc, weld puddle, and adjacent heated area protected from contamination

Answer 8

Externally applied gaseous shield, filler rod may or may not be added

Question 9

Why is GTAW Getting popular

Answer 9

Increasing use of high alloy metals and need for higher quality welds

Question 10

What does the use of bare filler metals eliminate

Answer 10

The use of flux and post-weld cleaning

Question 11

Is filler metal always required?

Answer 11

No

Question 12

What kind of power source is needed for GTAW when welding most steels and stainless steel?

Answer 12

CC (constant current) power source

Question 13

What power source is needed for GTAW when welding non ferrous metals (aluminum/magnesium)

Answer 13

AC (alternating current) that produces an additional high frequency current

Question 14

What allows control of gas flow, cooling media and current at the work point rather than only at the machine?

Answer 14

Remote control unit

Question 15

What are the two types of cooling SYTEMS that can be used on a GTAW torch

Answer 15

Air cooled and water cooled

Question 16

What is the most common head angle on a GTAW torch

Answer 16

120 degrees

Question 17

What prevents accidental arcing of the tungsten electrode at the back of the torch

Answer 17

Torch cap

Question 18

What part of the torch conveys shielding gas

Answer 18

Torch body

Question 19

What are two types of electrode collets

Answer 19

Split type or draw type

Question 20

What is a tungsten electrode considered as

Answer 20

Non-consumable

Question 21

How does the AWS identify each electrode type

Answer 21

Number and colour code system

Question 22

What are the two finishes electrodes come in

Answer 22

Ground and chemically cleaned

Question 23

What is the main purpose of shielding gas

Answer 23

To exclude the atmosphere from the weld puddle, electrode, and the end of the filler rod, to avoid contamination

Question 24

What gasses are normally used in the GTAW PROCESS

Answer 24

Argon, helium, and argon-helium mix

Question 25

How many times heavier is argon compared to air and helium

Answer 25

1.4 times air, 10 times helium

Question 26

What’s the common mixture of helium and argon

Answer 26

80% argon and 20% helium

Question 27

What is the disadvantage of using a gas mixture

Answer 27

Cost

Question 28

What do regulators control

Answer 28

Pressure not flow rates

Question 29

What indicates the flow of shielding gas

Answer 29

Flow meter

Question 30

Where are solenoid valves located if equipped

Answer 30

Inside the welding power source

Question 31

What is needed to push amperage through a conductor

Answer 31

Voltage

Question 32

What is the measurement of the number of electrons that flow past a given point in one second

Answer 32

Amperage

Question 33

What’s the most beneficial feature of DCEP

Answer 33

Cleaning action

Question 34

What is the most common current used in GTAW except on aluminum and magnesium

Answer 34

DCEN (straight polarity) For non ferrous metals

Question 35

What is considered high frequency

Answer 35

Over 16000 HZ

Question 36

What are the two ways to prep an electrode

Answer 36

Grinding and electric arc

Question 37

Grinding marks should be _________ on an electrode?

Answer 37

Longitudinal

Question 38

What is the thermal expansion rate of stainless compared to mild steel

Answer 38

50% greater

Question 39

Which current is much preferred for stainless steel

Answer 39

DCEN

Question 40

What is the oxidation on stainless steel known as

Answer 40

Sugaring effect

Question 41

What is the gas flow rate for welding sheet metal

Answer 41

20 CFH

Question 42

What are the 3 troubleshooting categories of GTAW

Answer 42

Process, electrical, mechanical

Question 43

What is the most probable cause of porosity in a Gtaw weld

Answer 43

Inadequate gas shielding

Question 44

What shielding gas is best suited for oxide removal on aluminum or magnesium

Answer 44

Argon

Question 45

What does a plasma cutter use for the power source

Answer 45

Plasma aggregates

Question 46

Where does the cutting by-product go when plasma cutting

Answer 46

Out the slit or kerf

Question 47

What safety equipment should be used when plasma cutting

Answer 47

Longs sleeves, gloves, eye protection

Question 48

What shade is acceptable for plasma cutting

Answer 48

7 or 9

Question 49

What are the two consumables on a plasma cutting torch

Answer 49

nozzle, electrode

Question 50

What is a kerf

Answer 50

Void created by the plasma cutting process or the amount of metal removed by the plasma arc

Question 51

Does nozzle size have a direct effect on kerf width?

Answer 51

Yes

Question 52

What are the bevel ranges for conventional plasma torches

Answer 52

1-3 on the good side of the cut and 3-8 on the bad side

Question 53

A bevel angle of greater than 5 degrees indicates a problem with PAC machine parameters T or F

Answer 53

True

Question 54

What is Dross?

Answer 54

Molten metal from the cut that has solidified before it was ejected

Question 55

How is Dross removed

Answer 55

grinding or filing