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

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

A

Visible light rays, ultraviolet light rays, infrared rays

1
Q

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

A

Wool, leather, denim and cotton because they repel sparks

2
Q

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

A

Darkness of the lense

3
Q

What are the three elements to start a fire

A

Heat fuel and oxygen

4
Q

What are the four classes of fire

A

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

5
Q

Why should you not cut over concrete floors

A

Because small explosions happen when slag hits the floor

6
Q

When should you have adequate ventilation

A

When heating cutting or using Oxyacetylene equipment

7
Q

When should you use an approved airline respirator

A

When heating or cutting metals that contains zinc

8
Q

Why should oxygen be considered a potential danger

A

Because it can promote burning or cause explosions

9
Q

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

A

2200 psi

70°F ( 21°C )

10
Q

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

A

Rusting

11
Q

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

A

3360 PSI

12
Q

What causes the oxygen cylinder rupture disk to release

A

Extreme pressure rise caused by heat or fire

13
Q

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

A

3200psi

Slow controlled release

14
Q

What are two key properties of acetylene

A

Colorless and a strong pungent odor

15
Q

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

A

2.5%-80%

16
Q

What is the maximum safe working pressure for acetylene

A

15 psi

17
Q

What psi can acetylene cylinders be safely stored at

A

250psi

18
Q

What is the percentage of acetone in an acetylene cylinder

A

40%

19
Q

What position must oxygen and acetylene cylinders be stored in

A

An upright position

20
Q

What does a draw limit mean

A

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

21
Q

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

A

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

22
Q

Acetylene cylinder valves use what hand thread

A

Left hand thread

23
Q

Oxygen cylinder valves use what hand thread

A

Right hand thread

24
Q

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

A

1-1/2–2 turns

25
Q

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

A

All of the way because it has a double seated valve

26
Q

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

A

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

27
Q

What are three characteristics of an argon gas

A

Colorless odorless and tasteless

28
Q

What is argon used for in industry

A

Purging purposes

29
Q

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

A

Mild steel
low alloy steel
and sometimes stainless steel

30
Q

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

A

Non-ferrous metals

31
Q

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

A

To reduce the cylinder pressure to a usable working pressure

32
Q

What color are oxygen regulators

A

Green

33
Q

What color are acetylene regulators

A

Red

34
Q

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

A

Single stage only shows the operating pressure

two stage shows cylinder pressure and operating pressure

35
Q

What is the minimum bursting pressure of oxyacetylene hoses

A

400psi

36
Q

What do flashback arrestors do

A

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

37
Q

Define a welding torch

A

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

38
Q

What kind of material are oxyacetylene welding tips made out of

A

Copper

39
Q

What are heating tips used for

A
Bending 
straightening 
preheating 
shrink Fits
bronze welding
40
Q

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

A

Add one psi

41
Q

What are the three main types of cutting torches

A

Combination welding
heavy duty hand cutting torch
machine torches

42
Q

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

A

Lash the cylinders together securely with chain or holding device

43
Q

What is a backfire

A

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

44
Q

What is burnback

A

A hot tip

faulty mixture and torch body seats

45
Q

What are suitable materials for cutting

A

Ferrous metals such as steel

46
Q

What are not suitable materials for cutting

A
Nonferrous metals such as 
Copper
brass 
bronze 
aluminium
47
Q

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

A

Neutral

48
Q

Where should you start a cut when using a torch

A

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

49
Q

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

A

Less

50
Q

What are drag or lag lines

A

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

51
Q

Describe a neutral flame

A

A point where the feather just disappears but no more

52
Q

Uses for a neutral flame

A
Fusion welding 
aluminum 
low-carbon steels
cast iron
Brazing
53
Q

What is an oxidizing flame

A

Any flame Richer in oxygen than neutral flame

54
Q

What is Capillary action or attraction

A

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

55
Q

What are two metals for EasyFlo brazing

A

Ferrous and non-ferrous metals

56
Q

Flux is used for what

A

Brazing

57
Q

How should you braze a pipe joint

A

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

58
Q

Why should you remove all traces of flux after silver brazing

A

Because it has a residue which is chemically corrosive

59
Q

What should the minimum included angle be in a joint design

A

90°

60
Q

What is a possible tensile strength when breeze welding

A

60,000psi

61
Q

What is a tiger torch

A

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

62
Q

What hand are the internal threads on a propane tank

A

Left hand thread

63
Q

What are temperature indicators used for

A

Preheating or component assembly