1. What is ASTM A671 CJB115 Class 33 Steel Pipe?
Answer: ASTM A671 CJB115 Class 33 is a premium electric-fusion-welded (EFW) carbon steel pipe designed for extreme high-pressure industrial applications (service temperature above -20°F/-29°C). The "Class 33" designation indicates a minimum yield strength of 33 ksi (228 MPa), making it suitable for the most demanding pressure systems.
2. Key Material Properties?
Answer:
Mechanical:
Yield Strength: ≥33 ksi (228 MPa)
Tensile Strength: 105-125 ksi (724-862 MPa)
Impact Test: Mandatory for all applications
Chemical:
Carbon (C): ≤0.35%
Manganese (Mn): 1.30-1.60%
P/S: ≤0.025% (strict control)
3. Typical Applications?
Answer:
Ultra-high-pressure hydraulic systems (5000+ psi)
Power plant critical steam lines
Offshore oil & gas risers
Nuclear auxiliary piping systems
4. How does it compare to Class 32 and Class 35?
Answer:
| Class | Yield Strength | Performance Level |
|---|---|---|
| 32 | 32 ksi | High-pressure |
| 33 | 33 ksi | Extreme-pressure |
| 35 | 35 ksi | Specialized applications |
5. Fabrication Requirements?
Answer:
Welding: Preheat (425°F min.) + PWHT (1150-1275°F)
Testing: Hydrostatic (3x design pressure) + 100% RT/UT + hardness testing
Forming: Hot forming mandatory
Certification: Full traceability with third-party inspection
