Torch Unit 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 • • • 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 more the amount of oxygen –Slower –Very slow heating time

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