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 gasGreen = oxygen

Always green in colorHave right-handed threadsMade of high carbon steelExtruded (made out of one piece of metal)Full tank has a pressure of 3360 psiOxygen in a cylinder is 97% pureDouble-seated valve made of brass so it’s soft and self-sealsOxygen speeds up the burning processInspected with a hydrostatic (water pressure) inspection every 10

years and stamped on tank when passedOpen all the way and SLOWLYThreaded 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 ringsNever use oil or grease on or around oxygen equipmentNever use oxygen to blow dirt off clothing or equipment

Always red in colorFull tank is 250 psiLeft-handed threads are identified by groove on hexUnstabilized (aceytlene in its natural state) is dangerous

above 15 psiPorous material absorbs aceytlene in the cylinderAcetone stabilizes acetyleneCylinder valves made of brass because it doesn’t sparkSafety device is fusible plug (temperature above 212

degrees F)Visual inspection every time it’s filledNever use laying on its sideOnly 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 flowFlash arrestors are used to prevent both back flow and

back flashBack fire is a loud popBack flash is burning in the handleMinimum distance between cutting area and torch

outfit should be at least 10 feetWhen 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 rosebudWhen using a tip cleaner to clean a torch tip, always

allow a small amount of gas to flowAlways cap cylinder before removing it from the cartSafety device on the hose is a check valveWelding tip size corresponds to flame sizeTip 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 time3)Back out t-screws4)Close handle valves5)Remove tip and replace the nut6)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