1. What is ASTM A671 CJH115 Class 13?
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 13: Hydrostatic test pressure of 13,000 psi (90 MPa).
Key feature: 8.3% higher pressure rating than Class 12 (13k vs. 12k psi).
2. Typical Applications?
Used in:
LNG plant intermediate-pressure piping
Cryogenic valve manifolds
Industrial gas distribution systems
Cold-climate chemical processing units
3. Manufacturing & Testing Requirements?
Double-welded construction with 100% radiographic examination.
Charpy V-notch testing at -50°F/-46°C (min. 20 ft-lb impact energy).
Normalized heat treatment for uniform mechanical properties.
Hardness control: ≤200 HBW (to ensure weldability).
4. Certified Mechanical Properties?
| Property | Value |
|---|---|
| Tensile Strength | ≥65 ksi (448 MPa) |
| Yield Strength | ≥40 ksi (276 MPa) |
| Elongation | ≥22% |
| Impact Toughness | 20 ft-lb at -46°C |
5. How does it compare to CJF115 pipes?
Higher nickel content (3.5% vs. CJF115's 2.25%) for better moderate-cryogenic performance.
Lower temp limit than CJF115 (-46°C vs. -60°C) but more cost-effective.
Ideal balance for applications needing 3.5% Ni toughness without extreme low-temp demands.
