1. Q: What is ASTM A105? Is it a pipe material?
A: No, ASTM A105 is a specification for carbon steel forgings (e.g., flanges, fittings), not pipes. Pipes that connect to A105 flanges are typically specified under standards like A106 or A53.
2. Q: What is the maximum carbon content typically found in standard carbon steel pipes like A106 Gr. B?
A: The maximum carbon content for A106 Gr. B is 0.30%.
3. Q: Why is hydrostatic testing performed on pipes?
A: To verify the strength and leak-tight integrity of the pipe under a specified test pressure (usually 1.5 times the design pressure) for a sustained period.
4. Q: What is the major risk when using carbon steel pipes in sour service (containing H2S)?
A: Hydrogen Induced Cracking (HIC) and Sulfide Stress Cracking (SSC). Special "sour service" grades with controlled hardness and chemistry (e.g., with killed steel practice) are required.
5. Q: What does "NPS" stand for?
A: Nominal Pipe Size. It is a dimensionless designator for pipe diameter. For example, NPS 12 corresponds to approximately a 12-inch outside diameter.
