1. What is ASTM A671 CC60 Class 23?
Definition: High-performance EFW pipe for cryogenic and high-pressure industrial service, designed to withstand extreme conditions.
Key Specs:
Yield Strength: 60 ksi (414 MPa) at -20°F (-29°C).
Pressure Rating: 10,000 psi (690 bar) (Class 23).
Material: Carbon steel with enhanced impact toughness (Charpy V-notch ≥20 ft-lb at -50°F/-45°C).
2. Applications
Oil & Gas:
High-pressure gas transmission (onshore/offshore).
LNG liquefaction plant piping.
Power & Industrial:
High-temperature steam lines (≤650°F/343°C).
Cryogenic storage systems.
3. Technical Requirements
| Property | Requirement | Test Standard (ASTM) |
|---|---|---|
| Hydrostatic Test | 1.5x design pressure (15,000 psi) | A671 Section 12 |
| Charpy Impact | ≥20 ft-lb (27 J) at -50°F (-45°C) | A673 (Group 2+) |
| NDT | 100% radiography or ultrasonic | E94 / E213 |
4. Manufacturing & QA
Process:
Double-submerged arc welding (DSAW) with automated defect detection.
Mandatory PWHT for thickness >1.5" (stress relief).
Certification:
Complies with ASME B31.3, API 5L PSL1, and ISO 3183.
Optional NACE MR0175 for sour service.
5. Operational Limits
Temperature: -50°F to 650°F (-45°C to 343°C).
Pressure: ≤10,000 psi (690 bar).
Standards:
ISO 3183:2025 (Pipeline systems).
ASME B31.8 (Gas transmission).
