Oxy-fuel Ect. Flashcards
What are three harmful rays that can be encountered when heating brazing and cutting
Visible light rays, ultraviolet light rays, infrared rays
What is the best clothing material for welding and cutting list 4 and why
Wool, leather, denim and cotton because they repel sparks
For welding cutting and brazing goggles what are the number systems for
Darkness of the lense
What are the three elements to start a fire
Heat fuel and oxygen
What are the four classes of fire
Class A wood and paper
Class B flammable liquids
Class C electrical
Class D combustible metals
Why should you not cut over concrete floors
Because small explosions happen when slag hits the floor
When should you have adequate ventilation
When heating cutting or using Oxyacetylene equipment
When should you use an approved airline respirator
When heating or cutting metals that contains zinc
Why should oxygen be considered a potential danger
Because it can promote burning or cause explosions
What is a new oxygen cylinder fully charge to and at what temp.
2200 psi
70°F ( 21°C )
Normally steel is not considered to be a combustible material although oxygen and moisture slowly oxidize steel in a process known as…..
Rusting
Oxygen cylinders are factory tested to 1 1/2 times working pressure what is that in PSI
3360 PSI
What causes the oxygen cylinder rupture disk to release
Extreme pressure rise caused by heat or fire
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
What are two key properties of acetylene
Colorless and a strong pungent odor
What is the percentage range of the explosive mixture of acetylene in air
2.5%-80%
What is the maximum safe working pressure for acetylene
15 psi
What psi can acetylene cylinders be safely stored at
250psi
What is the percentage of acetone in an acetylene cylinder
40%
What position must oxygen and acetylene cylinders be stored in
An upright position
What does a draw limit mean
It means the maximum amount of acetylene can be taken from the cylinder without drawing acetone
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)
Acetylene cylinder valves use what hand thread
Left hand thread
Oxygen cylinder valves use what hand thread
Right hand thread
What is the suggested amount of turns to open an acetylene valve
1-1/2–2 turns
How many turns should you open an oxygen cylinder valve and why
All of the way because it has a double seated valve
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
What are three characteristics of an argon gas
Colorless odorless and tasteless
What is argon used for in industry
Purging purposes
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
What kind of metals can be welded with argon and helium being the shielding gas
Non-ferrous metals
What is the purpose of the regulator for an oxygen and acetylene cylinder
To reduce the cylinder pressure to a usable working pressure
What color are oxygen regulators
Green
What color are acetylene regulators
Red
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
What is the minimum bursting pressure of oxyacetylene hoses
400psi
What do flashback arrestors do
Prevent flames from traveling in gases back from the torch to the regulator
Define a welding torch
A device that mixes oxygen and acetylene in the correct portions for oxyacetylene welding and cutting
What kind of material are oxyacetylene welding tips made out of
Copper
What are heating tips used for
Bending straightening preheating shrink Fits bronze welding
For every Oxyacetylene tip size you should do what to the psi
Add one psi
What are the three main types of cutting torches
Combination welding
heavy duty hand cutting torch
machine torches
What is the first procedure to do when setting up oxygen and acetylene cylinders
Lash the cylinders together securely with chain or holding device
What is a backfire
The flame backs up into the tip and mixer with a pop or bang
What is burnback
A hot tip
faulty mixture and torch body seats
What are suitable materials for cutting
Ferrous metals such as steel
What are not suitable materials for cutting
Nonferrous metals such as Copper brass bronze aluminium
What kind of flame should you have when checking preheat flames and cutting jetstream
Neutral
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
Should your torch inclination be more or less when cutting into a thicker material
Less
What are drag or lag lines
Lines that are caused by the jetstream while cutting of the workpiece takes place
Describe a neutral flame
A point where the feather just disappears but no more
Uses for a neutral flame
Fusion welding aluminum low-carbon steels cast iron Brazing
What is an oxidizing flame
Any flame Richer in oxygen than neutral flame
What is Capillary action or attraction
And liquid is drawn and spread through a very small space between two surfaces
What are two metals for EasyFlo brazing
Ferrous and non-ferrous metals
Flux is used for what
Brazing
How should you braze a pipe joint
Preheat the pipe then heat the joint while applying alloy to the corner of joint and pipe
Why should you remove all traces of flux after silver brazing
Because it has a residue which is chemically corrosive
What should the minimum included angle be in a joint design
90°
What is a possible tensile strength when breeze welding
60,000psi
What is a tiger torch
A heavy duty torch used in construction and maintenance shops for applications requiring intense heat
What hand are the internal threads on a propane tank
Left hand thread
What are temperature indicators used for
Preheating or component assembly
