Gas Heating, Cutting, Brazing, and Welding 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 Cutting tips Torch Cart Cylinders Valves Regulators Gauges Hoses
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 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
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 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
VOCABULARY Tip Cleaners- rods 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