Cutting Chapter 3 Flashcards
Plasma arc cutting uses a jet of plasma to what 3 things to metal?
Pierce
Cut
Gouge
How is the plasma created?
Super heating gas in an electric arc.
The temperature of the plasma is hot enough to melt what?
Any metal.
Plasma arc process can be set up for what two operations?
Manual
Mechanized
Plasma Arc in most cases is NOT faster and more efficient than any other cutting method.
F
PAC cuts ferrous and nonferrous metals.
T
Produces Max dros
F
Doesn’t create a minimal heat-affected zone
F
Causes little or no distortion
T
In the transferred arc process, the what is part of the electrical circuit as in other arc processes/
Workpiece
The arc is established between the what and the what?
And it is via what?
Electrode
Work
Arc Transfer Process
Larger industrial units are used for what two cuttings?
Heavy-duty manual cutting
General-duty mechanized cutting
What do PAC larger industrial units operate on?
Three phase 230/460VAC input power
PAC Larger industrial units can produce DC output currents up??
to 750 amperes.
The duty cycle of a PAC larger industrial unit usually is?
100 percent
PAC Larger industrial units can cut what 3 things?
Stainless steel
Aluminum up to 2.5” thick
Carbon steel up to 3” thick
The most comon plasma arc cutting torch uses what 2 things?
Pilot Arc
Transferred Arc Process
In many torches, a high frequency pilot arc is started between the what 2 things?
Electrode
Nozzle
The typical plasma arc cutting torch usually contains what? 4 things
Replaceable Retaining Cup
Copper Electrode w/ a hafnium or thoriated tungsten insert
Gas Swirl Ring
Nozzle (tip)
The most common parts that are changed in a torch are what 2 things?
Electrode
Nozzle
If cutting will be done near a battery, the battery must be what?
Removed
Why must the battery be moved during cutting?
Prevent hydrogen gas explosions caused by a cutting spark.
The simplest units use what to cut 3 things
Clean compressed air
Carbon steel
Stainless steel
Aluminum up to about 3/16” thick
Most heavy duty systems will require what 2 technically 4 things?
2 high-pressure cylinders
2 pressure regulators.
One cylinder contains the what and the other is a what
Cutting gas
Shielding or cooling gas
Light-gauge sheet steel may require as few as what amps?
While 2 inch aluminum plate may require how many amps?
7
250
When should safety caps be kept with cylinders?
At all times
Immediately after removing a cylinder’s regulator assembly, you do what?
Reinstall the safety cap over the cylinder valve.
To pierce very thin metal, hold the torch directly over the point to be pierced at a what degree work angle?
Then press what?
0
The arc button
As soon as the jet passes completely through the workplace you what?
Move the torch head in a smoot circle or other pattern to produce the desired diameter or shape for the hole.
In cylinders are to be removed, be sure to what?
Remove the pressure regulators and replace the cylinder caps before releasing and moving the cylinders.
If compressed air is used with a PAC unit, shop air may be used as long as it is what?
dry and free of oil/
When properly set, the air pressure regulator and filter/dryer on the power source will maintain what
the correct pressure and flow rate for the system.
A significant concern when using PAC equipment is that what?
Which can cause the torch to what?
moisture may enter the unit through the air line.
Sputter or Hiss
