1. Q: What do the designations "PSL1" and "PSL2" mean in API 5L?
A: They specify Product Specification Levels. PSL2 has more stringent chemical, mechanical, and testing requirements than PSL1.
2. Q: In API 5L, what does the suffix "M" or "S" indicate? (e.g., X65M)
A: "M" denotes the mandatory mechanical properties from a test piece machined from the pipe body. "S" denotes properties from a test piece machined from the strip/plate. Spiral pipe typically uses "M".
3. Q: What is the common welding method for the internal and external spiral seam?
A: Double-sided, two-pass Submerged Arc Welding (SAW) is standard.
4. Q: What is the purpose of the submerged arc in SAW?
A: It completely covers the arc and molten weld pool, preventing atmospheric contamination, stabilizing the arc, and improving weld quality and bead profile.
5. Q: What is a common inline Non-Destructive Testing (NDT) method for the weld seam?
A: Automated Ultrasonic Testing (AUT) is the primary method for 100% inspection of the helical weld.
