The Different Methods Of Welding Pipes

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There are numerous ways to manufacture pipes, the most prominent of which is centrifugal casting.  It involves a permanent mold wherein molten metal is poured and centrifugally thrown towards its inside wall.  The high-speed rotation and subsequent cooling of the metal produce a thin-walled cylinder with a very fine-grained outer diameter.

Another method of manufacturing pipes is the use of welding.  Most of the pipes created in the U.S. are produced through these welding techniques:  

Continuous weld

Continuous weld (CW) pipes are made from skelp – flat plates or strips of metal – that is rolled and shaped into a tubular shape through pressure (roll leveler) and heat (gas-fired furnace.)  The edges of the skelp are then welded together using welding rolls.

These pipes are typically used for transportation of fluids, both liquid and gas, and select structural applications.  

Electric resistance weld

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The electric resistance weld (ERW) method also uses skelp in forms of rolls or sheets.  ERW pipes, though, do not use heat. Instead, they are cold formed.  The edges of the skelp are welded at the seam using an electric current, with revolving copper discs serving as electrodes that raise the temperature to 2600 degrees Fahrenheit.  After normalization, the weld is cooled using air and water.

The primary procurers of ERW pipes are companies that transmit gas and oil.  

Chris Keehner is at the helm of Baltimore-based DS Pipe & Steel Supply LLC’s everyday operation.  He is credited as a major reason the company can efficiently supply steel and pipe products to seven states in the American northeast.  Visit the company website for more information.