Q: Name a common stainless steel grade for welded pipes.
A: ASTM A312 TP304/304L or TP316/316L, used for corrosion resistance.
Q: What does the "X" mean in API 5L X70?
A: It designates a high-strength line pipe grade with a specified minimum yield strength (SMYS) of 70,000 psi.
Q: What is ASTM A787 for?
A: It covers electric-resistance-welded metallic-coated steel mechanical tubing.
Q: What is a typical grade for boiler and heat exchanger tubes?
A: ASTM A178 (ERW) or ASTM A214 for carbon steel.
Q: What is the primary purpose of non-destructive testing (NDT) on the weld seam?
A: To detect internal or surface defects (like cracks, lack of fusion, porosity) without damaging the pipe.
