1. What is ASTM A671 CJH115 Class 11?
A specification for electric-fusion-welded steel pipe designed for low-temperature service (down to -50°F/-46°C).
CJH115: Carbon steel with 3.5% nickel for enhanced cryogenic toughness.
Class 11: Hydrostatic test pressure of 11,000 psi (76 MPa).
2. Key Applications?
Used in moderate cryogenic environments:
LNG auxiliary piping systems
Chemical processing plants
Refrigeration infrastructure
Cold storage facility pipelines
3. Manufacturing Requirements?
Double-welded construction (inside/outside welds)
100% radiographic examination
Charpy V-notch testing at -50°F
Normalized heat treatment
4. Mechanical Properties?
Tensile strength: ≥65 ksi (448 MPa)
Yield strength: ≥40 ksi (276 MPa)
Elongation: ≥22%
Impact toughness: 20 ft-lb minimum at test temp
5. How does it compare to CJF115 pipes?
Higher nickel content (3.5% vs 2.25% in CJF115)
Lower pressure rating (Class 11 vs Class 50+)
Better low-temp performance than non-nickel grades
More cost-effective for moderate cryogenic use
