1. What is a carbon steel pipe?
A carbon steel pipe is a tubular product made primarily from steel where carbon is the main alloying element. It does not require a minimum specified content of other alloying elements like chromium or molybdenum to achieve its desired properties -1.
2. What are the main classifications of carbon steel pipes based on manufacturing process?
They are mainly classified into seamless pipes (made by piercing a solid billet) and welded pipes (made by rolling a plate and welding the seam). Welded types include Electric Resistance Welded (ERW), Longitudinal Submerged Arc Welded (LSAW), and Spiral Submerged Arc Welded (SSAW) -1-8.
3. What is the difference between hot-finished and cold-finished seamless pipes?
Hot-finished pipes are formed at high temperatures (around 1200°C) and are suitable for larger diameters and thicker walls. Cold-finished (cold-drawn or cold-rolled) pipes start as hot-finished stock and are further processed at room temperature to achieve tighter dimensional tolerances, better surface finish, and higher strengths -1-9.
4. What does "Schedule" (SCH) mean in pipe specifications?
Schedule (SCH) refers to the wall thickness of the pipe. A higher schedule number indicates a thicker wall for a given nominal pipe size (NPS), which allows the pipe to withstand higher internal pressures. Common schedules include SCH 40, SCH 80, and SCH 160 -10.
5. What is the most common standard for high-temperature service seamless pipes?
ASTM A106 is the standard specification for seamless carbon steel pipes for high-temperature service. Grade B (A106 Gr. B) is the most widely used grade in this specification -2-10.
