L450 is a high-strength pipeline steel grade specified in API 5L. The letter "L" represents line pipe steel, while "450" indicates a minimum yield strength of 450 MPa, which is approximately 65.3 ksi and corresponds to Grade X65.
Through microalloying with niobium, vanadium, and titanium, combined with controlled rolling and cooling (TMCP), L450 develops a fine-grained microstructure that provides an excellent balance of high strength, low-temperature toughness, and field weldability.
GNEE Pipe supplies API 5L L450 (X65) line pipe in seamless (SMLS), ERW, and LSAW production forms, mainly in PSL2 quality, certified according to API 5L and GB/T 9711 standards.
Need a quote for your project? Send your grade, PSL level, size, and quantity. Our engineers will confirm specifications and delivery within 24 hours.
Key Specifications
| Parameter | Specification |
|---|---|
| Standard | API 5L (latest edition) / GB/T 9711 |
| Grade | L450 / X65 |
| PSL Level | PSL2 as standard, PSL1 available on request |
| Delivery Condition (PSL2) | X65M (TMCP) or X65Q (Quenched and Tempered) |
| Production Forms | Seamless (SMLS), ERW / HFW, LSAW |
| Size Range | NPS 2" – 56" (OD 60.3 – 1422 mm) |
| Length | SRL 5.8–6.0 m, DRL 11.8–12.0 m, or fixed length per order |
| Ends | Beveled ends (BE), plain ends (PE), threaded and coupled on request |
| Documentation | EN 10204 Type 3.1 Mill Test Certificate; third-party inspection available |
Important: According to API 5L 46th Edition, "X65 PSL2" should specify the delivery condition. The suffix M or Q must be included on purchase orders to avoid ambiguity.
Material Characteristics
API 5L X65 achieves its high strength through low-carbon chemistry, microalloying, and controlled manufacturing processes.
- Low carbon content: ≤0.12% for X65M (TMCP), ≤0.18% for X65Q.
- Low phosphorus: ≤0.025% for PSL2.
- Low sulfur: ≤0.015% for PSL2; sour service requirements may restrict sulfur to ≤0.003%.
- Microalloying elements: Niobium, vanadium, and titanium with combined Nb + V + Ti ≤0.15%.
The controlled composition and TMCP or quench-and-temper process provide the following performance advantages:
- Excellent low-temperature toughness with Charpy V-notch impact verification.
- Controlled strain-hardening behavior with yield-to-tensile ratio ≤0.93 for PSL2 applications.
- Good weldability with CE IIW ≤0.43 and Pcm ≤0.25.
- Hardness control ≤250 HV10 (≤248 HV10 for sour service).
Size Chart (SMLS / ERW)
Standard dimensions are based on ASME B36.10M. Heavier wall thicknesses and custom dimensions are available upon request.
| NPS | OD (mm) | Wall Thickness (mm) | Schedule | Weight (kg/m) | Form |
|---|---|---|---|---|---|
| 2" | 60.3 | 3.91 / 5.54 | SCH 40 / 80 | 5.44 / 7.48 | SMLS / ERW |
| 3" | 88.9 | 5.49 / 7.62 | SCH 40 / 80 | 11.29 / 15.27 | SMLS / ERW |
| 4" | 114.3 | 6.02 / 8.56 | SCH 40 / 80 | 16.07 / 22.32 | SMLS / ERW |
| 6" | 168.3 | 7.11 / 10.97 | SCH 40 / 80 | 28.26 / 42.56 | SMLS / ERW |
| 8" | 219.1 | 8.18 / 12.70 | SCH 40 / 80 | 42.55 / 64.64 | SMLS / ERW |
| 10" | 273.1 | 9.27 / 12.70 | SCH 40 / XS | 60.31 / 81.55 | SMLS / ERW |
For NPS ≤10", SCH 80 equals XS. For NPS 12" and above, SCH 80 and XS are different designations. LSAW sizes from NPS 16" to 56" are available on request.
Technical Parameters: L450 (X65) PSL1 vs PSL2
| Property | API 5L X65 PSL1 | API 5L X65 PSL2 (Recommended) |
|---|---|---|
| Yield Strength (min) | 450 MPa (65,300 psi) | 450 MPa (65,300 psi) |
| Yield Strength (max) | Not specified | 600 MPa (87,000 psi) |
| Tensile Strength (min) | 535 MPa (77,600 psi) | 535 MPa (77,600 psi) |
| Tensile Strength (max) | Not specified | 760 MPa (110,200 psi) |
| Impact Testing | Not required | Mandatory Charpy V-notch test |
| Carbon Equivalent | Not required | ≤0.43 |
| Crack Sensitivity (Pcm) | Not required | ≤0.25 |
| Hardness | Not specified | ≤250 HV10 |
| Sulfur (max) | 0.030% | 0.015% |
| Phosphorus (max) | 0.030% | 0.025% |
| Delivery Condition | Not restricted | M (TMCP) or Q (Quenched & Tempered) |
| Traceability | Standard | Full heat-to-pipe traceability |
| NDT | Basic inspection | 100% UT or RT |
Quality Testing
Every L450 (X65) line pipe undergoes strict inspection before shipment:
- 100% hydrostatic testing of every joint.
- Charpy V-notch impact testing for PSL2.
- Tensile and hardness testing according to PSL requirements.
- Ultrasonic testing of weld seams and pipe body where required.
- Third-party inspection by SGS, Bureau Veritas, Lloyd's, or customer-appointed agencies.
Production Processes
Seamless (SMLS)
Seamless X65 pipe is manufactured through piercing and hot rolling, followed by heat treatment according to the specified delivery condition. It is commonly supplied in Q condition for high-pressure applications such as gas injection lines and offshore risers.
LSAW (Longitudinal Submerged Arc Welding)
LSAW pipe is produced using JCOE or UOE forming technology, followed by internal and external submerged arc welding. Cold expansion improves dimensional accuracy and reduces residual stress, making it suitable for large-diameter offshore pipelines and trunkline projects.
ERW / HFW (High-Frequency Welding)
ERW/HFW is a cost-effective solution for small and medium diameter pipelines. High-frequency welding produces a clean weld seam without filler metal, and post-weld heat treatment improves weld toughness.
3PE & FBE Coating Options
3PE (Three-Layer Polyethylene)
3PE is widely used for buried pipelines. It combines FBE primer, adhesive layer, and HDPE outer protection to provide long-term resistance against soil corrosion and moisture.
FBE (Fusion Bonded Epoxy)
FBE coating provides excellent adhesion and cathodic disbondment resistance, making it suitable for offshore and humid environments.
Internal Epoxy Lining
Internal epoxy coating creates a smooth surface, reduces friction losses, improves flow efficiency, and protects against internal corrosion.
Packaging & Shipping
- End protection: Heavy-duty plastic caps or metallic bevel protectors prevent damage during loading and transportation.
- Corrosion protection: Bare pipes are coated with export-grade anti-rust varnish. Coated pipes are handled with nylon slings and protective supports.
- Shipping modes: Breakbulk shipping for large projects and container shipping for standard lengths.
Regular shipping routes include Santos, Callao, Valparaiso, and Buenos Aires. Competitive CFR solutions are available for international pipeline projects.
Reliable Supply to the South American Energy Hubs! Optimized logistics routes to Brazil, Chile, and Argentina. Don't let logistics delays stop your project. Check Our Current Production Schedule
API 5L Line Pipe MTC
Frequently Asked Questions
Is L450 the same as X65?
Yes. L450 and X65 are two designations of the same API 5L grade. L450 represents the minimum yield strength in MPa, while X65 represents the equivalent ksi value.
Why is PSL2 recommended for L450?
PSL2 provides stricter chemical control, mandatory impact testing, maximum strength limits, full traceability, and 100% non-destructive testing, making it suitable for demanding pipeline applications.
What delivery condition should I specify for X65 PSL2?
Specify X65M for thermomechanically rolled pipe or X65Q for quenched and tempered pipe. X65M is common for ERW and LSAW, while X65Q is often used for seamless applications.
What is the Charpy impact requirement for L450?
The impact requirement depends on pipe size, grade, and test temperature specified in the order. Typical values are around 27 J at 0°C, but project requirements should be confirmed before ordering.
Can you supply coatings for buried service?
Yes. GNEE Pipe can provide 3LPE, FBE, and internal epoxy coating solutions according to project specifications.
References
- API Specification 5L - Specification for Line Pipe (PSL1 / PSL2), 46th Edition.
- GB/T 9711 - Petroleum and Natural Gas Industries: Steel Pipe for Pipeline Transportation Systems.
- ASME B36.10M - Welded and Seamless Wrought Steel Pipe.
- EN 10204 - Metallic Products: Types of Inspection Documents.
Request a Quotation
Send your L450 / X65 grade, PSL level, delivery condition (M or Q), production form, size, wall thickness, length, coating requirements, and quantity to our engineering team.
We will confirm specifications, availability, and delivery schedule within 24 hours.
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