Transcript Document
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.
Check valves prevent a flame from reaching gas in the cylinder.
Hoses are flexible lines that carry gases.
Red = fuel gas
Green = oxygen
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
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
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
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
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
1)Close main valves (Acetylene first;
Oxygen second)
2)Bleed hoses one at a time
3)Back out t-screws
4)Close handle valves
5)Remove tip and replace the nut
6)Coil hoses
Acetylene
Oxygen
Cutting
5-8 psi
30-40 psi
Welding
5-8 psi
15-20 psi
Heating
8-10 psi
50 psi
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