Selected articles from October/November 2003 issue published on TheFabricator.com:
Welders are among the millions of workers who face respiratory hazards every day in the workplace. Confined spaces, solvents, and gas emissions, as well as welding, grinding, and soldering, may expose workers to airborne hazards.
The introduction of lasers to the manufacturing process has changed the fabrication of tubing. Today, many manual processes can be replaced with laser processing techniques. Using the flexibility afforded by lasers, a bundle of raw tubing can be loaded into a laser tube cutter; parts can be cut with high accuracy, quality, and speed; and then finished parts from the machine can be sent directly to the final assembly.
The engine roars to life, and Bruce Van Sant inches the motorcycle forward, stopping about 25 feet from the starting line. Alan Geetings, crew member of the Van Sant racing team, sprays the asphalt with water. Bruce revs up the engine. The engine's torque breaks the rear tire's grip on the asphalt and it spins furiously. The air is suddenly filled with a cloud of smoke and the smell of burning rubber. After heating the tire, Bruce approaches the starting line.
Early power supplies for contact and induction welding for tube production, which were introduced in the 1950s, operated at 300 to 400 kHz. Modern power supplied, introduced in the 1990s, are variable from 200 to 400 kHz. While using any frequency in this range can produce acceptable welds for most applications, finite element analysis can be helpful for finding the optimal frequency for a particular gauge and material.
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