1. What is ASTM A671 CJF115 Class 30?
Standard: EFW carbon steel pipe for critical low-temperature service (-115°F/-81.7°C)
Class 30: 30,000 psi (207 MPa) hydrostatic test pressure
Key Features:
"CJF115" = Charpy V-notch testing at -115°F (min. 50 ft-lb/68 J)
Triple-normalized + tempering heat treatment
2. Where is it typically used?
Industrial:
LNG export terminal main pipelines
Cryogenic heat exchanger systems
Energy:
Ultra-high-pressure gas transmission
Subzero refrigeration plants
3. Material properties?
Strength:
Tensile: ≥110 ksi (758 MPa)
Yield: ≥85 ksi (586 MPa)
Toughness:
Full-body impact mapping at -115°F
Min. elongation: 40%
Chemistry:
Carbon: ≤0.12%
S/P ≤0.004%
4. Manufacturing technology?
Welding:
EFW with triple normalization + tempering
Testing:
Hydrostatic: 30,000 psi (207 MPa)
NDE: RT + UT + TOFD (100% coverage)
Quality:
Laser-scanned dimensional verification
5. Fabrication protocols?
Welding:
Preheat: 600–800°F (316–427°C)
Mandatory PWHT for all thicknesses
Forming:
Cold bending (min. 30D radius)
Inspection:
Full NDE + hardness + microstructure analysis
