1. Q: What is the most common grade for general-purpose seamless carbon steel pipe?
A: ASTM A106 Grade B. It is widely used for pressure piping at moderate and high temperatures.
2. Q: Which grade of ASTM A53 pipe is seamless and suitable for threading and bending?
A: ASTM A53 Type S (Seamless) Grade B. (Type E is Electric Resistance Welded, Type F is Furnace Buttwelded).
3. Q: What is a key difference between ASTM A106 Grade A and Grade B?
A: Minimum tensile and yield strength. Grade B has higher strength (60 ksi min tensile, 35 ksi min yield) compared to Grade A (48 ksi min tensile, 30 ksi min yield).
4. Q: Name a common seamless grade used for high-temperature service (up to ~750°F).
A: ASTM A106 Grade C. It has the highest strength among A106 grades (70 ksi min tensile, 40 ksi min yield).
5. Q: Which API 5L grade is typical for onshore natural gas transmission pipelines?
A: API 5L Grade B or X42 to X65, depending on pressure and design requirements. Grade B (PSL1) is common for lower-pressure lines.
