What is ASTM A671 CJe115 Class 12?
A carbon steel pipe for atmospheric/low-temperature service, where "CJe115" indicates electric-fusion-welded construction with Charpy V-notch impact testing at -115°F (-81.7°C). Class 12 denotes 12,000 psi (83 MPa) hydrostatic test pressure.
Key applications?
Primarily used in low-temperature/pressure environments like:
Cryogenic storage tanks
Refrigeration systems
Cold climate piping networks
LNG/LPG auxiliary piping
Chemical composition requirements?
Typical ranges (weight %):
Carbon: ≤0.30%
Manganese: 0.29-1.25%
Phosphorus: ≤0.035%
Sulfur: ≤0.035%
Silicon content is often adjusted for low-temperature toughness.
Mechanical properties?
Tensile strength: ≥60 ksi (414 MPa)
Yield strength: ≥35 ksi (241 MPa)
Elongation: ≥22% (varies by wall thickness)
Mandatory impact testing at -115°F (-81.7°C) with minimum 15 ft-lb (20 J) absorbed energy.
Fabrication notes?
Welding requires preheat (200-400°F/93-204°C) and controlled cooling
Post-weld heat treatment often recommended
Cold bending permitted with restrictions on radius
Surface defects must be repaired per ASTM A671 Section 12
