API 5L X46N PSL2 Seamless Steel Pipe For Oil And Gas Pipeline

Dimension Specifications & Tolerance

·Outer Diameter Range: 70mm~610mm, custom non-standard sizes available

·Wall Thickness Range: 6mm~35mm, uniform wall thickness without eccentricity

·Standard Length: 6m, 9m, 12m, customized fixed lengths supported

·OD Tolerance: ±0.75%D (high-precision PSL2 tolerance)

·Wall Thickness Tolerance: -5%~+10%t, no excessive negative deviation

·Straightness: ≤1.5mm/m, smooth end face without burrs

API 5L X46N PSL2 normalized seamless line pipe is a high-grade seamless steel pipe manufactured in strict accordance withAPI SPEC 5L (46th Edition)international petroleum pipeline standard, corresponding to the national standard grade L320N.X46refers to a pipeline steel grade with a minimum yield strength of 320MPa; the suffixNstands for normalized heat treatment, which ensures uniform grain structure, excellent low-temperature toughness and stable weldability.PSL2 (Product Specification Level 2)is the premium grade of line pipe standard, featuring stricter chemical composition control, low-temperature impact requirements, dimensional tolerances and full non-destructive testing compared with PSL1, making it suitable for high-pressure, low-temperature and corrosive working condition

3LPE Coating

3LPE Three-Layer Polyethylene Coating (High-End Buried Pipeline Solution)

Adopting international standard three-layer composite anti-corrosion structure with factory integrated extrusion coating, featuring strong adhesion, aging resistance and soil corrosion resistance. It is the preferred anti-corrosion process for long-distance buried oil and gas pipelines.

Structural & Thickness Parameters:

·Bottom Layer: Fusion Bonded Epoxy (FBE): ≥120μm thickness, electrostatic spraying forms chemical bonding with steel substrate, excellent cathodic delamination resistance and penetration resistance

·Middle Layer: Copolymer Adhesive: 170~250μm thickness, tightly bonds epoxy layer and PE layer with zero delamination

·Top Layer: High-Density Polyethylene (HDPE): ≥2.5mm for OD ≤406mm; ≥3.0mm for OD >406mm, superior wear, impact and acid-alkali resistance

·Total Coating Thickness: Standard grade ≥3.0mm, Reinforced grade ≥3.3mm

Core Process & Testing Indicators:

·Surface Pretreatment: Sand blasting to Sa2.5 grade, surface roughness 40~80μm, complete removal of oxide and oil stains

·Processing Temperature: Epoxy curing at 200℃, PE extrusion at 290~310℃, roller pressure 0.05~0.08MPa

·Performance: Oxidation induction time ≥30min (220℃), carbon black content ≥2.0%, service life ≥50 years

·Inspection: Spark leakage detection, breakdown voltage ≥3000V, no pinholes or damages

FAQ (Frequently Asked Questions)

Q1: What is the key difference between X46N and ordinary X46 steel pipe?

The core difference lies inheat treatment and comprehensive performance. X46N adopts normalized treatment to refine grain structure and eliminate rolling residual stress, delivering excellent low-temperature toughness, stable weldability and superior fatigue resistance. Ordinary X46 pipes without normalization have poor toughness and are prone to stress cracking, only suitable for normal-temperature and low-pressure common working conditions. X46N is applicable for severe low-temperature, high-pressure and corrosive environments.

Q2: How to choose between PSL2 and PSL1? Can they be mixed used?

Mixing use is not recommended. PSL2 is the premium pipeline steel grade with mandatory low-temperature impact tests, stricter component tolerance and full-coverage non-destructive testing, designed for long-distance oil & gas transmission, high-pressure, low-temperature and key projects. PSL1 has no mandatory impact requirements and loose parameter tolerances, only for ordinary low-pressure & normal-temperature fluid transportation. PSL2 is mandatory for key projects, export orders and high-pressure working conditions.

Q3: How to select the three anti-corrosion coatings for different working conditions?

1.3LPE Coating: Premium choice for long-distance buried oil & gas pipelines, saline-alkali soil and high-corrosion areas, service life over 50 years with higher cost performance for long-term projects; 2.Black Varnish Coating: Economic option for municipal water supply & drainage and ordinary buried pipelines with excellent cost performance; 3.Hot-Dip Galvanized Coating: Ideal for outdoor overhead pipelines and humid atmospheric corrosion environments with low maintenance cost.

Q4: Is customized processing available? What is the delivery cycle?

Full customization is supported, including non-standard diameter & wall thickness, fixed length, beveling, special thickened coating and internal & external surface treatment. Conventional specifications are in stock with 3-5 days delivery; customized and special coating orders take 7-10 days, supporting mass batch production.

Q5: Can the pipe be constructed at low temperature? Will brittle fracture occur in cold environments?

No brittle fracture occurs. Featuring normalized X46N process and PSL2 premium grade, the pipe has a standard 0℃ Charpy impact energy ≥27J and excellent low-temperature toughness, resisting extreme low temperature down to -40℃. It fully adapts to winter low-temperature construction in northern regions and cold-area pipeline service, serving as professional low-temperature resistant line pipe.

Q6: Are the anti-corrosion layers wear-resistant and aging-resistant? Will coating peel off during transportation and installation?

All three coatings adopt industrial high-standard processes with reliable durability. 3LPE coating features ultra-strong adhesion and impact resistance against soil friction; black varnish film is dense and flexible; galvanized layer forms metallurgical bonding without peeling. No coating damage or peeling occurs under standard transportation, hoisting and installation. Reinforced coating is available for harsh construction conditions.

Q7: Does the product support third-party testing? What is the warranty policy?

All products support full SGS third-party re-inspection and fully comply with API 5L standards. Official warranty: 15-year warranty for steel substrate, over 30-year warranty for 3LPE coating, over 20-year warranty for galvanized coating, and 10-year warranty for black varnish coating. Lifetime technical after-sales service is provided for non-human damage and non-violent usage.