What is TP316LN Stainless Steel Seamless Pipe?
SeamlessTP316LN stainless steel pipe (UNS S31653 / W.Nr. 1.4406 / 1.4429) is a nitrogen-strengthened, ultra-low carbon austenitic stainless steel designed for high-stress, corrosive, and cryogenic environments.
Manufactured through a seamless process (hot piercing + precision cold drawing), it ensures:
- No weld seams or weak points
- Uniform microstructure
- Superior pressure resistance
- Excellent corrosion performance
The“LN” designationindicates:
- L (Low Carbon ≤0.03%) → Prevents intergranular corrosion and sensitization
- N (Nitrogen 0.10–0.16%) → Enhances strength and corrosion resistance
Compared with standard 316L, TP316LN offers significantly higher mechanical strength and improved corrosion resistance, making it ideal for critical engineering applications.
Key Features & Technical Advantages
Higher Strength & Reduced Weight
Nitrogen addition increases:
- Yield strength
- Tensile strength
- Design stress capability
Enablesthinner wall pipes, reducing material and system costs.
Superior Corrosion Resistance (High PREN)
The combination of Molybdenum + Nitrogenimproves:
- Pitting resistance
- Crevice corrosion resistance
- Performance in chloride-rich environments
Excellent Resistance to Intergranular Corrosion
Ultra-low carbon content ensures:
- No chromium carbide precipitation
- Stability in welding heat-affected zones
- Compliance with sensitization-resistant design
Outstanding Cryogenic Performance
TP316LN maintains:
- High toughness at -196°C (LNG temperature)
- Stable mechanical properties at low temperatures
Widely used in LNG, aerospace, and cryogenic storage systems
High Pressure Integrity
Manufactured in accordance with:
- ASTM A312
- EN 10216-5
Ensures safe operation in high-pressure fluid transport systems
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for 316LN stainless steel.
The composition of Stainless Steel 316LN is carefully balanced to achieve its superior strength and corrosion resistance.
Stainless Steel 316LN is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
These physical properties highlight the material’s ability to perform reliably under a wide range of conditions.
Industrial Applications
TP316LN seamless pipes are widely used in high-reliability industries:
Nuclear & Power Generation
- Heat exchangers
- Reactor systems
- Control mechanisms
Chemical & Petrochemical
- Urea production
- Acetic acid systems
- High-pressure reactors
Cryogenic & LNG
- LNG pipelines
- Liquid oxygen systems
- Cryogenic storage tanks
Offshore & Marine
- Subsea pipelines
- Hydraulic systems
- Instrumentation tubing
Pharmaceutical & Food Industry
- High-purity process systems
- CIP/SIP cleaning environments
Dimensional Standards & Tolerances
We manufacture TP316LN pipes in strict compliance with international standards:
ASTM / EN / JIS / GB
- ASTM A312
- EN 10216-5
- JIS G3459
- GB/T 14976
Typical tolerances:
- OD tolerance: ±0.2 mm to ±0.5%
- Wall thickness: ±7.5% to ±20%
- Length: per standard or customized
Suitable for precision engineering and critical systems
Quality Assurance & Testing
Every TP316LN pipe is fully inspected and certified:
Certification
- EN 10204 3.1 / 3.2 Material Test Certificates (MTC)
Testing & Inspection
- 100% PMI (Positive Material Identification)
- Ultrasonic Testing (UT)
- Eddy Current Testing (ET)
- Hydrostatic Testing
Advanced Testing
- ASTM A262 Intergranular Corrosion (IGC)
- Grain size (ASTM E112)
- Flattening & flaring tests
Third-Party Inspection
ABS
DNV
BV (Bureau Veritas)
TÜV
SGS
