Torch Unit

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Torch Unit

• Gas Heating, Cutting, Brazing, and Welding

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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

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Popular Gases for Welding

• Oxygen
• Acetylene
• Oxygen is NOT a fuel

• Oxyacetylene- a shortened version of the word
  oxygen and acetylene

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VOCABULARY

• Manifold System- a pipe with 2 or more outlets
• Rig- a self contained apparatus assembled to
  conduct an operation

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OXYACETYLENE EQUIPMENT

• Cutting tips
• Torch

• Cart
• Cylinders
• Valves
• Regulators
• Gauges
• Hoses

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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

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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

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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

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OXYGEN

• Creates intense burning and very high
  temperatures
• Watch out for oil and other contaminants

• Contains 2200 lbs per square inch pressure
• Store in the upright position
• Store with cap on except while in use

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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)

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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)

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ACETYLENE TANKS (cont)

• Has fusible plugs
• Very explosive at 15 psi or higher
• Valve turned with a special key

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ALTERNATIVE TORCH FUEL SOURCES

• Propane
• Burns at 4800 degrees
• Uses 4 times the amount of oxygen
• Very slow heating time

• MAPP Gas
• Burns at most 5300 degrees
• Requires more oxygen
• Slower heating

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VOCABULARY

• Tip Cleaners- rods with rough edges designed to
  remove soot, dirt, or metal, residue from the tip

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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

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Unit 23

• Cutting With Oxyfuels

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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

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(cont)

• 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

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BRAZING

• Process of bonding with metals and alloys that
  melt at 840 degrees F.

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FUSION WELDING

• Joining metal by melting it together
• 2 pieces become 1

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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

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Torch Information

• Piercing Steel- means to create a hole
• Flux- given to any chemical used to clean metal
• Tinning- key to soldering

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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

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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

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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