1. What is A671 CA55 Class 10 Steel Pipe?
A: It's an electric-fusion-welded (EFW) carbon steel pipe designed for low-temperature service (down to -50°F/-45°C). The "CA55" denotes its chemical composition and testing requirements, while "Class 10" specifies its pressure rating (e.g., 10,000 psi hydrostatic test).
Key Use: Cryogenic applications, LNG systems, and low-pressure piping.
2. What Standards Govern A671 CA55 Class 10 Pipes?
A: It complies with ASTM A671, which covers EFW pipes for atmospheric/lower-temperature service. Key requirements:
Material: Carbon steel with controlled chemistry (e.g., silicon, carbon).
Testing: Hydrostatic, nondestructive (radiographic/ultrasonic), and Charpy impact tests (for low-temp toughness).
3. How Does Class 10 Compare to Other Classes (e.g., Class 20/30)?
A:
Pressure Capacity: Class 10 = 10,000 psi test pressure; Class 20 = 20,000 psi, etc.
Wall Thickness: Class 10 typically has thinner walls than higher classes.
Application: Class 10 suits moderate pressure; Class 20+ for high-pressure systems.
4. What Are the Welding and Fabrication Requirements?
A:
Welding: Submerged arc welding (SAW) or similar, with 100% radiographic inspection.
Post-Weld Heat Treatment (PWHT): Often required to relieve stresses.
Fabrication Tolerance: Follows ASTM A671 dimensions (e.g., OD, wall thickness).
5. Where Are A671 CA55 Class 10 Pipes Commonly Used?
A: Typical applications include:
Oil & Gas: Cryogenic storage, refinery piping.
Power Plants: Low-temp coolant lines.
Chemical Processing: Handling liquefied gases (e.g., ammonia).
