1. Gas Heating, Cutting, Brazing, and Welding
Torch Unit
Gas Heating, Cutting, Brazing, and Welding

2. 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

3. Popular Gases for Welding
Oxygen
Acetylene
*Oxygen is NOT a fuel*
Oxyacetylene- a shortened version of the word oxygen and acetylene

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

5. OXYACETYLENE EQUIPMENT
Cutting tips
Torch
Cart
Cylinders
Valves
Regulators
Gauges
Hoses

6. 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

7. 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

8. 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

9. 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

10. 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)

11. 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)

12. ACETYLENE TANKS (cont)
Has fusible plugs
Very explosive at 15 psi or higher
Valve turned with a special key

13. 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

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

15. 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

16. Unit 23
Cutting With Oxyfuels

17. 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

18. (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

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

20. FUSION WELDING
Joining metal by melting it together
2 pieces become 1

21. 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

22. Torch Information Piercing Steel- means to create a hole
Flux- given to any chemical used to clean metal
Tinning- key to soldering

23. 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

24. 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

25. 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