Q: What does the "L" in API 5L stand for?
A: The "L" stands for "Line pipe," indicating the standard is for pipes used in pipeline transportation systems.
Q: Which stainless steel grade is most common for corrosion-resistant welded tubes?
A: AISI 304 (UNS S30400) is the most widely used austenitic stainless steel grade.
Q: What is the primary difference between ERW and SAW pipes?
A: ERW (Electric Resistance Welding) uses electric current to heat and forge the seam, while SAW (Submerged Arc Welding) uses a granular flux to shield an arc welding process, typically for thicker walls.
Q: At what stage is the weld seam heat-treated in HFI (High-Frequency Induction) welding?
A: The weld seam is typically heat-treated (normalized) immediately after welding to refine the grain structure in the heat-affected zone (HAZ).
Q: What does the "D" stand for in the manufacturing process "DSAW"?
A: "D" stands for "Double." DSAW pipes have a weld seam on both the inside and outside.
