API 5L X65 LSAW Welded Line Pipe
API 5L X65 LSAW (Longitudinal Submerged Arc Welded) Pipe is a high-strength line pipe widely used in high-pressure, long-distance transportation systems for oil, gas, and other fluids. With a minimum yield strength of 448 MPa (65 ksi), it offers excellent weldability, toughness, and corrosion resistance, making it a mainstream choice for onshore and offshore pipeline projects.
Need API 5L X65 Pipe for High-Pressure Oil/Gas Lines? Our PSL2-Grade Tubes Meet -40℃ Impact Toughness & Sour Service Requirements. Get a Free Material Test Report Now!
API 5L X65 pipeline for oil and gas Specifications
| Item | Parameter |
|---|---|
| Standard | API 5L / ISO 3183 |
| Grade | X65 / L450 |
| Manufacturing Process | Longitudinal Submerged Arc Welding (LSAW), JCOE, UOE |
| Outer Diameter Range | Φ219 mm to Φ1422 mm (8"–56") |
| Wall Thickness Range | 6–40 mm (customizable) |
| Length | SRL (Single Random Length), DRL (Double Random Length), or fixed length |
| Product Specification Level | PSL1, PSL2 (including Sour Service) |
API 5L X65 Oil pipe Mechanical Properties (PSL2 Requirements)
| Property | Requirement (PSL2) |
|---|---|
| Minimum Yield Strength | ≥448 MPa (65 ksi) |
| Tensile Strength | ≥535 MPa |
| Yield-to-Tensile Ratio (Y/T) | ≤0.93 |
| Elongation | ≥18% (varies with diameter and wall thickness) |
| Charpy V-Notch Impact Energy at -20°C | ≥80 J |
| Hardness (HV10) | ≤250 HV |
API 5L X65 Line Pipes for oil & gas Chemical Composition (PSL2, Maximum %)
| Element | Max Content (%) | Notes |
|---|---|---|
| Carbon (C) | ≤0.28 | Controlled CEQ for weldability |
| Manganese (Mn) | ≤1.40 | Enhances strength and toughness |
| Phosphorus (P) | ≤0.025 | Reduces brittleness |
| Sulfur (S) | ≤0.015 | Minimizes segregation and hot cracking |
| Vanadium (V), Niobium (Nb), Titanium (Ti) | Trace additions | Grain refinement and strengthening |
| Carbon Equivalent (CEQ) | ≤0.43 | Mandatory for PSL2 to ensure weldability |
Pipe End Types for API 5L X65 Carbon Steel Line Pipe
| Type | Description |
|---|---|
| Beveled Ends | Most common, prepared for field welding, bevel angle typically 30°±5° |
| Plain Ends | Used for short connections or flanged joints |
| Threaded Ends | With coupling, suitable for small-diameter or repair applications |
| Grooved Ends | For quick coupling installation, commonly used in urban utility networks |
API 5L X65 Oil and gas pipe lines Production Processes
Plate Preprocessing
Hot-rolled coils or plates are leveled and milled to ensure edge quality and forming accuracy.
Forming Process
JCOE: Progressive press forming, suitable for medium to large diameters with lower equipment cost.
UOE: One-step hydraulic forming, offers superior dimensional accuracy, ideal for thick-walled large-diameter pipes.
Welding
Multi-wire submerged arc welding (SAWL) is employed, combined with real-time ultrasonic inspection to ensure weld integrity.
Expansion
Full-body mechanical expansion eliminates residual stresses and improves dimensional stability and fatigue life.
Heat Treatment
PSL1: Optional normalization or TMCP (Thermo-Mechanical Control Process)
PSL2: Typically requires normalization, TMCP, or quenching and tempering (Q&T), especially for X65Q variants
Post-Processing
Hydrostatic testing (1.5× design pressure, held for 10 seconds)
Anti-corrosion coating (e.g., 3PE, FBE)
100% non-destructive testing (UT, RT, ET)
API 5L X65 Line Pipes for oil & gas Delivery Conditions
| Condition | Description |
|---|---|
| PSL1 | Manufacturer may choose delivery condition (e.g., as-rolled, normalized) |
| PSL2 | Must comply with ordered specification, typically: |
| - Normalized | |
| - TMCP (Thermo-Mechanical Control Process) | |
| - Quenched & Tempered (Q&T) for X65Q grade |
API 5L X65 Carbon Steel Welded Pipe Applications
Long-Distance Oil & Gas Pipelines: e.g., China-Russia East Line, Central Asia D Line
Urban High-Pressure Gas Networks: Φ406 mm and below for city gate stations to pressure regulation stations
Offshore Engineering: Subsea pipelines, compatible with cathodic protection up to 1800 m water depth
Sour Service Environments: X65MS grade resists H₂S corrosion, suitable for high-sulfur gas fields
Extreme Climate Zones: Excellent low-temperature toughness down to -40°C, ideal for Arctic and permafrost regions
API 5L X65 High Yield Line Pipes Quality Assurance
| Requirement | PSL1 | PSL2 |
|---|---|---|
| Weld NDT | Sampling inspection | 100% volumetric inspection (UT/RT) |
| Body NDT | Not required | 100% body inspection (UT/ET) |
| Charpy Impact Test | Not mandatory | Mandatory at -20°C (≥80 J) |
| HIC/SSC Testing | Not required | Required for sour service applications |
| Third-Party Inspection | Optional | Mandatory (e.g., SGS, BV reports) |
API 5L Pipeline factory
API 5L Line pipe packaging and shipping
FAQ
What is the difference between X60 and X65 pipe?
The minimum yield strength of X65 is 450MPa, which is higher than the 415MPa of X60. It has better pressure bearing capacity and structural strength, and is suitable for high-pressure and harsh environments such as deep sea and high cold; The X65 carbon equivalent control is stricter in terms of chemical composition (≤ 0.45%), and the impact toughness (-20 ℃ Charpy impact energy ≥ 80J) and non-destructive testing requirements under PSL2 standard are more stringent, suitable for sulfur-containing and low-temperature working conditions. X65 has more outstanding performance and safety, but the cost is higher. The selection needs to be comprehensively considered based on the conveying pressure, environmental conditions, and project standards.
What type of pipe is API 5L X65?
API 5L X65 pipeline steel belongs to seamless or welded steel pipes for high-strength oil and gas transportation, mainly used in long-distance and high-pressure pipeline systems for fluids such as oil and natural gas. It is one of the core pipes in modern energy infrastructure.
Hot Tags: api 5l x65 lsaw welded line pipe, China api 5l x65 lsaw welded line pipe manufacturers, suppliers, A335 Alloy Steel Pipes, API 5L PSL1, ASTM A691 1 1 4CR Welded Pipe, P12 Alloy Steel Pipe, Straight Seam Pipe, straight seam submerged arc welded SAWL steel pipe
You Might Also Like
Send Inquiry