What Is Oxyfuel Welding? 100

acetone

A flammable liquid used in acetylene cylinders to dissolve and store acetylene.

acetylene

A colorless, flammable gas that is used in oxyfuel welding. Acetylene is the most commonly used gas for mixing with oxygen to fuel oxyfuel torches.

airtight

Not allowing any gases or air to penetrate. An airtight joint will not leak any gas.

aluminum

A silvery white metal that is soft, light, and has a high strength-to-weight ratio. Aluminum is one of the most difficult metals to weld.

arc welding

A joining process that uses electricity to generate the heat needed to melt the base metals.

braze pool

The pool formed by the melted filler metal during braze welding. The temperature to melt the filler metal is low enough that the pieces being joined do not melt.

braze welding

A process in which a filler metal is melted at a temperature above 840° F (450° C), but below the melting point of the base metals to fill in a gap between two base metals. Braze welding differs from brazing because the filler metal is used to fill a gap.

brazing

A joining process that is used to combine dissimilar metals at temperatures lower than welding.

butt joint

A joint formed by joining two pieces of metal edge to edge.

capillary action

The ability of a substance to draw a liquid upwards against the force of gravity. In brazing, capillary action causes a filler metal to be drawn into the space between workpieces.

copper

A reddish metal that is very ductile, thermally and electrically conductive, and corrosion resistant. Copper can be welded using limited methods.

cutting

The use of an oxyfuel torch to separate metal from a workpiece. Oxyfuel cutting uses an additional high-pressure stream of oxygen to cut metal.

cylinder

A container for compressed gases. Each gas is stored in a unique type of cylinder.

die

A reusable mold that holds heated liquid metal and imparts its shape as the metal cools. Oxygen cylinders are shaped in dies.

distillation

The process by which oxygen is extracted from the air to be stored in a cylinder.

ductility

The ability of a metal to be drawn, stretched, or formed without breaking.

edge joint

A joint formed by joining the edges of two pieces of metal that are parallel to each other.

ferrous metal

A metal that contains iron. Ferrous metals are the most common type of welded metal.

filler metal

A type of metal sometimes added to the joint in fusion welding. Filler metal adds to the strength and mass of the welded joint.

flashback

A torch malfunction in which the flame briefly or continually moves up into the torch and hoses. If a flame reaches the hoses, an explosion can occur.

flashback arrestor

A part of an oxyfuel outfit that is installed between the hoses and the torch. A flashback arrestor reduces the chances of flashback occurring while a torch is used.

flux

A non-metallic material used to protect the weld puddle and solid metal from atmospheric contamination.

hose connector

The part of an oxyfuel torch where the flashback arrestor is attached to the torch.

impurities

Any elements contained in an oxyfuel weld that are not the metal being joined or the filler metal.

injector

The part of an injector torch that pulls low-pressure acetylene into the torch and mixes it with oxygen.

injector torch

A type of torch that uses lower-pressure acetylene and features an internal injector that pulls the acetylene into the torch.

in-tip mixer

A welding tip that contains a mixing chamber as part of the tip.

joining

Bringing two separate materials together through some type of forming. Joining is one of the main ways metals can be formed.

lap joint

A joint formed by two overlapping pieces of metal.

low-carbon steel

Carbon steels that contain less than 0.3% carbon. Also referred to as mild steel, low-carbon steel is the most commonly welded metal.

MAPP gas

Also called methylacetylene-propadiene gas. A liquefied petroleum gas that can be used in oxyfuel processes. The main disadvantage of MAPP gass is that it costs much more than acetylene.

metal

A hard, crystalline solid that conducts electricity and heat. It is shiny when polished, and it can be hammered, bent, formed, and machined.

mixing chamber

A part of an oxyfuel outfit that is connected to the tip of the torch, or is part of the tip. The mixing chamber is where the two gases are combined before being burned by the flame.

non-ferrous metal

A metal that does not contain iron. Nonferrous metals are more difficult to weld than ferrous metals.

orifice

The hole or holes at the end of a torch tip. The shape and number of holes determine the use of the tip.

outside corner joint

A joint formed by the edges of two metal pieces being welded together at an angle of around 90 degrees. The weld is done on the outside of the corner.

oxide

A chemical compund containing oxygen and one other element. Oxides form during oxyfuel welding are harmful to the weld.

oxyfuel welding

A joining process that uses a mix of gases to fuel a torch to join two metal parts.

oxygen

A nonmetallic element that is colorless, odorless, and tasteless. Oxygen is one of the two gases used in oxyfuel welding.

porous

Full of holes that allow the material to absorb liquids. The material inside an acetylene cylinder is porous, enabling it to hold acetone.

positive pressure torch

A torch that uses equal pressures of oxygen and acetylene and does not have an injector.

propylene

Also known as propene. A flammable gas that can be used in oxyfuel welding instead of acetylene.

soldering

A joining process in which a filler metal is melted at temperatures below 840° (450° C) to form a joint between two base metals. Soldering is often used for delicate projects such as jewelry and electronics.

stainless steel

A type of steel that contains more than 15% chromium and exhibits excellent corrosion resistance. Stainless steel can be welded using many methods.

T-joint

A joint formed when the edge of one piece is welded to the surface of another piece at a 90° angle.

torch

A tool used to generate the flame for oxyfuel welding by mixing oxygen and a fuel gas, usually acetylene.

torch body

Also called the handle. The part of the torch held by the welder. Inside the torch body are hoses which direct the flow of gases to the mixing chamber.

unstable

Highly reactive and dangerous, possibly explosive. Unstable chemicals require careful handling to ensure safety.

valve

The part of the torch used to regulate the amount of oxygen and fuel gas flowing into the torch.

watertight

Not allowing any liquids to penetrate. A watertight joint will not leak any liquids at all.

welding rod

Also know as a filler metal. Filler metals come in rods that are used during the welding process.

welding tip

The end of the torch where the flame is ignited. Tips are usually interchangable, and are made of solid copper.