C4 - LT#2 Flashcards
When you turn the pressure-adjusting screw on the regulator all the way it, it _______
closes the regulator
The lines are said to be ______ when the cylinder valves are open, working pressures are set and the torch valves are closed.
Pressurized
An acetylene cylinder valve outlet for the regulator is left-hand threaded and _____ threaded as an extra precaution against improper set-up
Internally
An oxygen cylinder valve outlet for the regulator is right-handed threaded and ______ threaded as an extra precaution against improper set-up
Externally
Before you light a torch, always check for ______ in the line
Leaks
The only thing that should be used to create a spark for lighting a torch is a _____
Flint striker
A flame that has an excessive amount of acetylene compared to a neutral flame is called a ______
carburizing flame
when oxygen is added to the acetylene flame, the flame changes color from yellow red to
blue
Name the three types of Oxyacetylene flame that can be produced:
1) Neutral flame
2) Carburizing (reducing flame)
3) Oxidizing flame
When shutting down the flame, first close the ______
Acetylene torch valve
(A BEFORE O)
If the cutting plate 13 mm (1/2”) or thicker, hold the cutting tip ______
Perpendicular to the plate
The cutting oxygen lever should be depressed when the metal has been preheated to a ______ color
Cherry red
The vertical lines created on the cut edge by the cutting action on metal are called:
Drag lines
Name 4 factors that can affect the quality of an oxyacetylene cut:
1) Working pressure setting
2) amount of preheated flame
3) angle of the torch tip relative to the metal
4) tip-sized speed of cutting torch across the meter
If the inner cone is pointed and the flame hisses, too much oxygen has been added - this is a
oxidizing flame (excess oxygen)
the flame is blue, with a dark blue feathered cone. This is is a
Carburizing flame (excess acetylene)
A neutral flame is ideal for:
Fusion welding and preheating steel for cutting - (Temps range from 3075 c to 3237 c)
A carburizing flame is used for:
Brazing and other applications where oxidizing the metal would cause poor welds or where lower flame temp is required
An oxidizing flame is used for:
Braze welding due to it’s cleaning effect on the base metal
Can non-ferrous alloys be cut with the oxyacetylene process?
No, cannot be cut if it contains no iron
Angling the torch 90 degrees for which thickness of metal?
For 13 mm or greater
For a plate 6 to 13 mm, what should the cutting tip be angled at?
60 to 70 degrees
For a plate than 6 mm (1/4”) thick, tip the angle at 15 degrees to
20 degrees
The tip should remain how far above the plate at all times?
10 mm
Since RFCV are sensitive and may become plugged, how often should they be tested?
At least once a week
What is the pressure test?
Increase the working pressures to 10 PSI, after opening the cylinder valves. After adjusting the working pressure, close both the cylinder valves again and watch the cylinder pressure gauges for pressure drop. Make sure the torch valves are closed.
What must you be equipped with for welding?
Safety goggles, heavy leather gloves, coveralls, boots and a welding cap
What does bleeding the lines mean?
Releasing of the gas pressure is still in the system.
How do you bleed the lines?
Tightly close the acetylene cylinder valve first, then the oxygen cylinder valve.
Next, open the acetylene torch valve, pressure readings on both acetylene gauges will drop to zero.
