Fillet Weld

A fillet weld is a triangular weld used to join two surfaces that are at approximately right angles to each other. i.e., lap, tee, and corner joints are normally welded with a fillet weld. A fillet weld should have a leg length equal to the plate thickness up to 3/8-inch plate. For plate thicknesses 3/8-inch and greater, … Read more

Welding Health Protection And Ventilation

All welding and thermal cutting operations carried on in confined spaces must be adequately ventilated to prevent the accumulation of toxic materials, combustible gases, or possible oxygen deficiency. Monitoring instruments should be used to detect harmful atmospheres. Where it is impossible to provide adequate ventilation, air-supplied respirators or hose masks approved for this purpose must … Read more

Welding In Confined Spaces

Welding in confined spaces is intended to mean welding in a relatively small or restricted space such as a tank, boiler, pressure vessel, or small compartment of a ship or tank. When welding or cutting is being performed in any confined space, the gas cylinders and welding machines shall be left on the outside. Before operations … Read more

General Welding Safety

General Welding Safety Precautions a. To prevent injury to personnel, extreme caution should be exercised when using any type of welding equipment. Injury can result from fire, explosions, electric shock, or harmful agents. Both the general and specific safety precautions listed below must be strictly observed by workers who weld or cut metals. b. Do not permit … Read more

Protective Welding Screens

a. When welding is done near other personnel, welding screen should be used to protect their eyes from the arc or reflected glare. b. In addition to using portable screens to protect other personnel, welding screen should be used, when necessary, to prevent drafts of air from interfering with the stability of the arc. c. … Read more

Plasma Arc Welding Safety

When plasma arc welding, safety is an important consideration. Plasma arc welding is a process in which coalescence is produced by heating with a constricted arc between an electrode and the workpiece (transfer arc) or the electrode and the constricting nozzle (non-transfer arc). Shielding is obtained from the hot ionized gas issuing from the orifice which … Read more

MAPP Gas Cylinders Safety

a. MAPP gas is a mixture of stabilized methylacetylene and propadiene. b. Store liquid MAPP gas around 70°F (21°C) and under 94 PSIG pressure. c. Repair any leaks immediately. MAPP gas vaporizes when the valve is opened and is difficult to detect visually. However, MAPP gas has an obnoxious odor detectable at 100 parts per … Read more

Trial Weld

As in all welding, good root penetration and avoidance of defects are important. In some cases, a trial weld will be required on-site. This should be done at the working depth and in the most difficult position required, usually overhead. The specimen weld should be brought to the surface and inspected before the actual welding commences. A … Read more

Expansion And Contraction In Welding Operations

Most welding processes involve heat. High-temperature heat is responsible for much of the expansion and contraction in welding operations because warpage and stress occur. When metal is heated, it expands in all directions. When the metal cools, it contracts in all directions. Some distortions caused by weld shrinkage are shown in the figure above. There … Read more

Arc Welding

The term arc welding applies to a large and varied group of processes that use an electric arc as the source of heat to melt and join metals. In arc welding processes, the joining of metals, or weld, is produced by the extreme heat of an electric arc drawn between an electrode and the workpiece, or between … Read more