1. Oxyacetylene
Torches

2. Oxyacetylene is a combination of the words oxygen and acetylene
Oxyacetylene is a combination of the words oxygen and acetylene. It refers to the equipment and processes where 2 gases are used together. (In our set up we use MAPP gas and oxygen.)
MAPP = methylacetylene-propadiene
A portable oxyacetylene rig includes a cart, cylinders, valves, regulators, gauges, hoses, & torch assemblies.
Torch is an assembly that mixes gases and discharges them to support a controllable flame.
A gas cylinder is a long round tank with extremely thick walls built to hold gases under pressure.
Valve is a device that allows gas to flow from cylinder.
Regulator is device that keeps the pressure of flowing gas at a constant rate.
Gauge is mounted on a regulator to measure and indicate pressure in the hose, tank, or manifold.

4. Check valves prevent a flame from reaching gas in the cylinder.
Hoses are flexible lines that carry gases.
Red = fuel gas
Green = oxygen

5. Oxygen Cylinders Always green in color Have right-handed threads
Made of high carbon steel
Extruded (made out of one piece of metal)
Full tank has a pressure of 3360 psi
Oxygen in a cylinder is 97% pure
Double-seated valve made of brass so it’s soft and self-seals
Oxygen speeds up the burning process
Inspected with a hydrostatic (water pressure) inspection every 10 years and stamped on tank when passed
Open all the way and SLOWLY
Threaded ring on top oxygen cylinder holds cap on (never attempt to move without cap on!)
Tank owners’ names are stamped on top of cylinder by the rings
Never use oil or grease on or around oxygen equipment
Never use oxygen to blow dirt off clothing or equipment

6. Acetylene Cylinder Always red in color Full tank is 250 psi
Left-handed threads are identified by groove on hex
Unstabilized (aceytlene in its natural state) is dangerous above 15 psi
Porous material absorbs aceytlene in the cylinder
Acetone stabilizes acetylene
Cylinder valves made of brass because it doesn’t spark
Safety device is fusible plug (temperature above 212 degrees F)
Visual inspection every time it’s filled
Never use laying on its side
Only open ¼ turn

7. ReGULATORS
Reduce cylinder pressure to adjustable, safe constant line pressure
A metallic filter in the stem of the gauge to prevent damage to the hose.
Turning the regulators t-screw to the right increases the working pressure
Backing out t-screw all the way will stop working pressure
Regulator gauge closest to the cylinder indicates tank pressure
Oxygen regulator provides a 3360 psi bursting disk

8. Basic Info when Using Torches
Work area must be cleared of all flammable materials
First step before using a torch outfit is to crack each cylinder valve one at a time to clear away any dirt or dust before connecting the regulators and lines
Light the torch with a striker
Check valves are used to prevent back flow
Flash arrestors are used to prevent both back flow and back flash
Back fire is a loud pop
Back flash is burning in the handle
Minimum distance between cutting area and torch outfit should be at least 10 feet
When bleed the hoses, bleed them on at a time

9. When shutting down a torch outfit, bleed the hoses before backing out the regulator t-screws
Size of a tip is determined by the hole diameter of it (hole is 1/3 of plate thickness)
The large heating tip is called a rosebud
When using a tip cleaner to clean a torch tip, always allow a small amount of gas to flow
Always cap cylinder before removing it from the cart
Safety device on the hose is a check valve
Welding tip size corresponds to flame size
Tip cleaners are rods with rough edges designed to remove soot, dirt, or metal residue from the hole in the tip

10. Shutting Down a Torch System
Close main valves (Acetylene first; Oxygen second)
Bleed hoses one at a time
Back out t-screws
Close handle valves
Remove tip and replace the nut
Coil hoses

11. 3 Types of Flames Acetylene Oxygen Cutting 5-8 psi 30-40 psi Welding
Heating
8-10 psi
50 psi
3 Types of Flames
Carburizing Flame: coolest flame; 5,000 degrees F; used to weld lead and case hardening; hot inner core with a white-hot acetylene feather and blue outer cone
Neutral Flame: 5900 degrees F; light blue inner core and darker blue to colorless outer cone; most commonly used flame
Oxidizing Flame: hottest flame; 6300 degrees F; inner cone has purplish tint and more pointed; loudest flame; used for welding copper and zinc base metals