Q: Name a standard for spiral welded steel pipe used in piling applications.
A: ASTM A252 covers welded and seamless steel pipe piles, with spiral weld pipe commonly used for this purpose in Grades 1, 2, and 3.
Q: What is a typical tolerance for the outside diameter of large-diameter spiral welded pipe?
A: Per standards like API 5L or EN 10219, the tolerance is often ±0.5% of the nominal diameter or a fixed value like ±3 mm, whichever is greater, for diameters over 500mm.
Q: Why is the submerged arc welding (SAW) process universally used for spiral pipe manufacture?
A: SAW provides deep penetration, high deposition rates, excellent weld quality with smooth bead profile, and superior mechanical properties, making it ideal for the automated, continuous production of spiral weld seams.
Q: What steel grade is specified for spiral welded pipe in low-temperature Arctic service?
A: API 5L grades like X65 or X70, with PSL2 requirements for enhanced low-temperature toughness (e.g., Charpy V-notch requirements at -20°C or lower), are commonly used.
Q: What is the role of the internal weld bead trimming device in modern spiral mills?
A: It removes the internal weld bead (reinforcement) to create a smooth bore, which is critical for pipeline efficiency (reduced turbulence) and for tools like pipeline inspection gauges (PIGs) to pass through.
