Oxy-fuel Ect. Flashcards Preview

Millwright 2nd Year > Oxy-fuel Ect. > Flashcards

Flashcards in Oxy-fuel Ect. Deck (64):
0

What is the best clothing material for welding and cutting list 4 and why

Wool, leather, denim and cotton because they repel sparks

1

What are three harmful rays that can be encountered when heating brazing and cutting

Visible light rays, ultraviolet light rays, infrared rays

2

For welding cutting and brazing goggles what are the number systems for

Darkness of the lense

3

What are the three elements to start a fire

Heat fuel and oxygen

4

What are the four classes of fire

Class A wood and paper
Class B flammable liquids
Class C electrical
Class D combustible metals

5

Why should you not cut over concrete floors

Because small explosions happen when slag hits the floor

6

When should you have adequate ventilation

When heating cutting or using Oxyacetylene equipment

7

When should you use an approved airline respirator

When heating or cutting metals that contains zinc

8

Why should oxygen be considered a potential danger

Because it can promote burning or cause explosions

9

What is a new oxygen cylinder fully charge to and at what temp.

2200 psi
70°F ( 21°C )

10

Normally steel is not considered to be a combustible material although oxygen and moisture slowly oxidize steel in a process known as.....

Rusting

11

Oxygen cylinders are factory tested to 1 1/2 times working pressure what is that in PSI

3360 PSI

12

What causes the oxygen cylinder rupture disk to release

Extreme pressure rise caused by heat or fire

13

At what psi does the rupture disk on an oxygen cylinder valve burst at and is it a slow or a fast release of gas

3200psi
Slow controlled release

14

What are two key properties of acetylene

Colorless and a strong pungent odor

15

What is the percentage range of the explosive mixture of acetylene in air

2.5%-80%

16

What is the maximum safe working pressure for acetylene

15 psi

17

What psi can acetylene cylinders be safely stored at

250psi

18

What is the percentage of acetone in an acetylene cylinder

40%

19

What position must oxygen and acetylene cylinders be stored in

An upright position

20

What does a draw limit mean

It means the maximum amount of acetylene can be taken from the cylinder without drawing acetone

21

What is the purpose of a fusible plug and what temperature does it melt at

To melt out in case of a fire allowing a slow controlled escape of gas
212°F (100°C)

22

Acetylene cylinder valves use what hand thread

Left hand thread

23

Oxygen cylinder valves use what hand thread

Right hand thread

24

What is the suggested amount of turns to open an acetylene valve

1-1/2--2 turns

25

How many turns should you open an oxygen cylinder valve and why

All of the way because it has a double seated valve

26

What should you do when mounting and oxygen and acetylene cylinder so they don't get banged into or knocked over

Secure them with chain and position them so this doesn't happen

27

What are three characteristics of an argon gas

Colorless odorless and tasteless

28

What is argon used for in industry

Purging purposes

29

What kind of metals are used when using argon and carbon dioxide as a shielding gas

Mild steel
low alloy steel
and sometimes stainless steel

30

What kind of metals can be welded with argon and helium being the shielding gas

Non-ferrous metals

31

What is the purpose of the regulator for an oxygen and acetylene cylinder

To reduce the cylinder pressure to a usable working pressure

32

What color are oxygen regulators

Green

33

What color are acetylene regulators

Red

34

What is the difference between a single stage and a two stage regulator

Single stage only shows the operating pressure
two stage shows cylinder pressure and operating pressure

35

What is the minimum bursting pressure of oxyacetylene hoses

400psi

36

What do flashback arrestors do

Prevent flames from traveling in gases back from the torch to the regulator

37

Define a welding torch

A device that mixes oxygen and acetylene in the correct portions for oxyacetylene welding and cutting

38

What kind of material are oxyacetylene welding tips made out of

Copper

39

What are heating tips used for

Bending
straightening
preheating
shrink Fits
bronze welding

40

For every Oxyacetylene tip size you should do what to the psi

Add one psi

41

What are the three main types of cutting torches

Combination welding
heavy duty hand cutting torch
machine torches

42

What is the first procedure to do when setting up oxygen and acetylene cylinders

Lash the cylinders together securely with chain or holding device

43

What is a backfire

The flame backs up into the tip and mixer with a pop or bang

44

What is burnback

A hot tip
faulty mixture and torch body seats

45

What are suitable materials for cutting

Ferrous metals such as steel

46

What are not suitable materials for cutting

Nonferrous metals such as
Copper
brass
bronze
aluminium

47

What kind of flame should you have when checking preheat flames and cutting jetstream

Neutral

48

Where should you start a cut when using a torch

sharp edge on a projection or at a whole where preheating will be easiest and fastest

49

Should your torch inclination be more or less when cutting into a thicker material

Less

50

What are drag or lag lines

Lines that are caused by the jetstream while cutting of the workpiece takes place

51

Describe a neutral flame

A point where the feather just disappears but no more

52

Uses for a neutral flame

Fusion welding
aluminum
low-carbon steels
cast iron
Brazing

53

What is an oxidizing flame

Any flame Richer in oxygen than neutral flame

54

What is Capillary action or attraction

And liquid is drawn and spread through a very small space between two surfaces

55

What are two metals for EasyFlo brazing

Ferrous and non-ferrous metals

56

Flux is used for what

Brazing

57

How should you braze a pipe joint

Preheat the pipe then heat the joint while applying alloy to the corner of joint and pipe

58

Why should you remove all traces of flux after silver brazing

Because it has a residue which is chemically corrosive

59

What should the minimum included angle be in a joint design

90°

60

What is a possible tensile strength when breeze welding

60,000psi

61

What is a tiger torch

A heavy duty torch used in construction and maintenance shops for applications requiring intense heat

62

What hand are the internal threads on a propane tank

Left hand thread

63

What are temperature indicators used for

Preheating or component assembly