Download Torch Unit Notes

Torch Unit
Gas Heating, Cutting,
Brazing, and Welding
VOCABULARY
• Weld- to join w/ a filler rod
• Fusion- melting together
• Gas- any fluid substance that can
expand without limit
• Compress- to apply pressure to
reduce in volume (very dangerous)
• Flammable- burns easily
Popular Gases for Welding
• Oxygen
• Acetylene
*Oxygen is NOT a fuel*
•Oxyacetylene- a shortened
version of the word oxygen and
acetylene
VOCABULARY
• Manifold System- a pipe with 2
or more outlets
• Rig- a self contained apparatus
assembled to conduct an
operation
OXYACETYLENE
EQUIPMENT
•
•
•
•
•
•
Cart
Cylinders
Valves
Regulators
Gauges
Hoses
• Cutting tips
• Torch
DEFINITIONS
• Torch-an assembly that mixes
gases and discharges them to
support a controllable flame
• Gas Cylinder- long, round tank
with extremely thick walls built to
withstand great pressure
DEFINITIONS (cont)
• Valves and Regulators- devices that
control or regulate the flow of gas
• Gauge- measures and indicates the
pressure in the hose, tank, or
manifold
• Hose-flexible line that carries gas
DEFINITIONS (cont)
• Acetylene- red hoses, left hand
threads
• Oxygen- green hoses, right hand
threads
• Crack the cylinder- turning on/off
quickly to remove any dust from the
opening
OXYGEN
• Creates intense • Contains 2200
burning and
lbs per square
very high
inch pressure
temperatures
• Store in the
• Watch out for oil upright position
and other
• Store with cap
contaminants
on except while
in use
ACETYLENE
• Most common fuel used in torches
• Made of carbon and hydrogen
• Combines with oxygen to create a
really intense flame
• Uses oxygen very efficiently
• Has a bad odor (which is good)
ACETYLENE TANKS
• Contain 250 lbs per square inch
pressure
• MUST be stored in upright position
• Balsa wood and acetone are stored
inside the tank with the acetylene
(prevents sloshing)
ACETYLENE TANKS (cont)
• Has fusible plugs
• Very explosive at 15 psi or higher
• Valve turned with a special key
ALTERNATIVE TORCH
FUEL SOURCES
• Propane
• MAPP Gas
–Burns at 4800
–Burns at most
degrees
5300 degrees
–Uses 4 times
–Requires
the amount of
more oxygen
oxygen
–Slower
–Very slow
heating
heating time
VOCABULARY
• Tip Cleanersrods with rough
edges designed
to remove soot,
dirt, or metal,
residue from the
tip
Torch Safety Considerations
• When shutting off the torches turn
the acetylene off first = fuel on and
off first! (Torch valves NOT Tank
Valves)
• Bleeding the lines is the removal of
all gases from the hoses
Unit 23
Cutting With Oxyfuels
DEFINITIONS
• Slag- a product formed during the
process of burning
–Good insulator
–Hinders cutting and welding
• Heating- temperature raises high
enough to soften a metal for
bending and shaping
(con’t)
• Oxyfuel Cutting- a process in which
steel is heated to the point where it
burns and is removed to leave a
thin slit called a kerf
• Acetylene- the most suitable for
welding
BRAZING
• Process of bonding with metals and
alloys that melt at 840 degrees F.
FUSION WELDING
• Joining metal by melting it together
– 2 pieces become 1
Characteristics of Torch
Cutting
• Clearance- torch tip to the metal
–Primary flames are almost level
with the surface of the metal
• Speed- important in proper cutting
• Pressure- improper cutting
appearance
Torch Information
• Piercing Steel- means to create a
hole
• Flux- given to any chemical used to
clean metal
• Tinning- key to soldering
Torch Information
• Torch adjustment- all welds are
completed with a neutral frame
• Bead- continuous and uniform line
of filler metal
• Puddle- small pool of liquid
metal
• Butt weld- a bead laid between 2
pieces of metal set edge to edge
Torch Information
• Fillet weld- a weld placed in a joint
created by a 90 degree angle
• Impurity- any product other than the
base
• Solidify- to turn from a liquid to a
solid
• Burn through- the process whereby
the cool side of metal becomes
molten and a hole opens in the
surface due to excessive heat
Torch Information
• Puddling- to create a bead by
puddling with out a filler rod is
called pushing the puddle
• Corner Weld- one made on edges
laid together to form a corner
• Back-Stepping- making short welds
in the backward direction as the
process progresses