1. What is the difference between seamless and welded carbon steel pipe?
Seamless pipe is manufactured by piercing a solid steel billet and then rolling it into a tube, resulting in a pipe with no seams or joints. Welded pipe is made by rolling a steel plate or coil into a cylindrical shape and then welding the edges together -4.
2. Which is stronger: seamless or welded pipe?
Generally, seamless pipe is considered stronger because it has a homogeneous structure without a weld seam, which can be a potential weak point. This makes it ideal for high-pressure and high-temperature applications -4-6.
3. When should I choose welded pipe over seamless?
Welded pipe is often a more economical choice, especially for large-diameter applications. Modern welding techniques like Electric Resistance Welding (ERW) and Submerged Arc Welding (SAW) produce high-quality pipes suitable for low to medium-pressure services, construction, and structural applications -4.
4. What are ERW, LSAW, and HSAW pipes?
These are types of welded pipe. ERW (Electric Resistance Welding) uses high-frequency current to weld the seam and is common for small to medium diameters. LSAW (Longitudinal Submerged Arc Welding) involves welding in a straight line and is used for large diameters and thicker walls. HSAW (Helical Submerged Arc Welding) , also known as spiral weld, is made by spirally welding a coil and is cost-effective for very large diameters -1-10.
5. What is the difference between hot-rolled and cold-rolled/cold-drawn seamless pipes?
Hot-rolled pipes are formed at high temperatures, resulting in a rougher surface but good toughness, making them suitable for standard applications. Cold-rolled/cold-drawn pipes are processed at room temperature, which gives them precise dimensional tolerances, a smoother surface finish, and higher strength, but they can have higher residual stress -7.
