ERW and Seamless pipes are both commonly used types of steel pipes, but they are manufactured differently and have distinct characteristics. Here’s how to identify them:
1. Manufacturing Process:
ERW: ERW pipes are manufactured by rolling metal and then welding it longitudinally along its length. This welding process typically involves using electric resistance to melt and fuse the edges of the metal together.
Seamless: Seamless pipes are made from a solid billet of steel that is heated and then drilled or extruded into a tube without any welding. No seam is present because the tube is formed from a single piece of material.
2. Appearance:
ERW: The cross-section of an ERW pipe will have a weld seam, which is a visible line where the two edges of the metal were fused together. This seam is a clear indication that the pipe is welded.
Seamless: The cross-section of a seamless pipe will be smooth and continuous, with no visible weld seams.
3. Size Range:
ERW: ERW pipes can be manufactured in a range of sizes, but they typically have a maximum outer diameter of 24 inches.
Seamless: Seamless pipes can be produced in a wide range of sizes, with outer diameters typically ranging from 1/8 inch to 26 inches.
4. Applications:
ERW: ERW pipes are commonly used in lower to medium pressure applications, such as water and oil transportation.
Seamless: Seamless pipes are often used in high-pressure applications, such as in the hydrocarbon industry, refinery operations, petroleum and natural gas exploration and drilling, as well as in air and hydraulic cylinders, bearings, boilers, and automobiles.
In summary, identifying whether a pipe is ERW or seamless involves looking at its manufacturing process, appearance, size range, and typical applications. If you need to check a specific pipe, feel along its length for any sign of a weld or seam. This can be the simplest way to distinguish between the two.
