1. Q: What is the typical end finish for seamless pipe to be welded?
A: Plain ends (PE) or beveled ends (BE). Beveled ends (typically 37.5°) are prepared for welding, often with a small root face (1.6mm).
2. Q: What is the purpose of normalizing heat treatment on seamless pipe like A106?
A: To refine the grain structure, improve toughness, and achieve uniform mechanical properties throughout the pipe, especially after the hot-working process.
3. Q: What does "P Number" in ASME Boiler and Pressure Vessel Code Section IX mean for pipe welding?
A: It groups base metals for procedure qualification. Most carbon steel seamless pipes (A106 Gr.B, A53) fall under P-Number 1, simplifying welder qualification across these grades.
4. Q: What is the key limitation of standard carbon steel seamless pipe (e.g., A106) in chemical service?
A: Poor corrosion resistance to many acids, caustics, and oxidizing environments. It is primarily used for utility streams (water, steam, air) or hydrocarbons without significant corrosives.
5. Q: Why is seamless pipe often specified over welded for high-pressure applications (>1000 psi)?
A: The absence of a longitudinal weld seam eliminates a potential plane of weakness, providing more uniform strength and reliability under cyclic pressure loading.
