API 5L X70 LSAW Steel Pipe With External 3LPE Coating

API 5L X70 LSAW (Longitudinal Submerged Arc Welded) steel pipe is a high-strength, high-precision longitudinal welded line pipe manufactured in full compliance with API 5L standard (PSL1/PSL2). It is specially designed for long-distance, high-pressure oil, natural gas and fluid transmission projects. Equipped with external 3LPE (3-Layer Polyethylene) anti-corrosion coating, the pipe features excellent corrosion resistance, mechanical impact resistance, UV aging resistance and long service life, perfectly adapting to harsh outdoor, underground and marine working environments.

Compared with SSAW and seamless steel pipes, X70 LSAW pipe has uniform wall thickness, stable weld performance and high dimensional accuracy, which can effectively reduce pipeline construction and maintenance costs. The upgraded UV-stabilized 3LPE coating further enhances outdoor durability, making it the preferred pipeline solution for global energy transmission engineering.

3LPE Anti-Corrosion Coating & Packaging Details

1. 3LPE Coating Structural Specifications (Standard SY/T 0413 & ISO 21809)

The external 3LPE coating is a three-layer composite anti-corrosion system, consisting of FBE primer, adhesive copolymer layer and PE outer layer, with strict thickness standards and performance parameters:

·First Layer: FBE Epoxy Primer: Minimum thickness ≥80μm, conventional controlled at 100-150μm. It provides primary chemical anti-corrosion protection, forms tight chemical bonding with the steel pipe surface, and effectively isolates electrochemical corrosion caused by soil and moisture.

·Second Layer: Copolymer Adhesive Layer: Thickness 170-250μm. It acts as a transition bonding layer, perfectly connecting the FBE primer and PE outer layer, avoiding coating delamination and peeling, and improving overall structural stability.

·Third Layer: Polyethylene Outer Protective Layer: Thickness varies by pipe diameter: 2.2-2.9mm for DN≤250, 2.5-3.2mm for DN500, 3.0-3.7mm for DN≥800. Adopts upgraded UV-stabilized PE material with 2.5% carbon black content (higher than the standard 2.0%), passing 1000-hour QUV accelerated weathering test with gloss retention ≥80% and peel strength maintained above 200 N/cm after UV exposure.

2. Coating Performance Advantages

The 3LPE coating system is recognized as the gold standard for pipeline anti-corrosion. It features strong acid, alkali and salt corrosion resistance, excellent mechanical wear resistance, low water absorption and no environmental pollution. The whole coating has no pinholes, cracks or bubbles, with high insulation resistance, effectively extending the pipeline service life to more than 50 years.

3. Professional Packaging & Shipping Protection Details

·Pipe End Protection: Equipped with customized plastic pipe end caps to prevent port deformation, coating damage and foreign matter entering the pipe interior.

·Surface Protection: Wrap each pipe with waterproof and dust-proof plastic film and woven cloth to avoid friction scratches, dust adhesion and rain erosion during transportation and storage.

·Bundle Fixation: Adopt steel strapping and fixed brackets for bundling, with reasonable stacking spacing to prevent extrusion deformation and coating peeling during long-distance transportation.

·Marking Traceability: Each pipe is permanently marked with standard information including API 5L X70 grade, PSL level, diameter, wall thickness, heat number, production date and coating specification for full life-cycle traceability.

·Container Loading: Professional container loading scheme with cushioning pads and anti-slip measures to ensure intact product delivery for sea and land transportation.

Application Fields

API 5L X70 3LPE LSAW steel pipe is widely used in global high-pressure and long-distance energy transmission and industrial pipeline projects, covering multiple core fields:

·Oil & Gas Transmission: Long-distance onshore and offshore natural gas, crude oil and refined oil transmission trunk pipelines, suitable for high-pressure transmission working conditions.

·Petrochemical Engineering: Fluid transmission pipelines for petrochemical plants, chemical medium transportation and supporting pipeline networks.

·Water Conservancy & Municipal Engineering: Large-scale urban water supply, drainage pipeline networks, cross-river and cross-basin water transmission projects.

·Energy & Power Industry: Cooling water pipelines, thermal power pipeline supporting projects, new energy supporting transmission pipelines.

·Marine & Offshore Projects: Offshore platform auxiliary pipelines, coastal buried pipelines, adapting to high-salt and high-humidity marine corrosive environment.

·Mining Industry: Mine slurry transmission, tailings discharge pipelines and other heavy-duty industrial pipeline systems.

FAQ

Q1: What is the difference between X70 LSAW pipe and ordinary welded pipe?

X70 LSAW pipe adopts double-sided longitudinal submerged arc welding process, with uniform weld seam, stable mechanical performance and high dimensional accuracy. It meets the high-standard pressure resistance and safety requirements of energy transmission pipelines. Compared with ordinary welded pipes, it has higher yield strength, better low-temperature toughness and stronger pressure bearing capacity, and is more suitable for long-distance and high-pressure engineering projects.

Q2: What are the advantages of your upgraded 3LPE coating compared with standard 3LPE?

Our 3LPE coating adds upgraded UV-stabilization formula with carbon black content increased from standard 2.0% to 2.5%. It passes 1000-hour QUV accelerated weathering test with gloss retention ≥80%, and the peel strength still remains above 200 N/cm after UV exposure. It effectively solves the problem of aging and powdering of ordinary 3LPE coating under long-term outdoor sunlight exposure, greatly improving outdoor service life.

Q3: Can you provide customized specifications and coating thickness?

Yes. We support full customization of pipe diameter, wall thickness, fixed length and 3LPE coating thickness according to customer project requirements. We can also provide matching solutions such as internal epoxy coating, FBE single-layer anti-corrosion and 3LPP coating to meet different working environment and engineering standard requirements.

Q4: What quality inspection reports can you provide?

We can provide complete factory inspection reports, including chemical composition analysis, mechanical property test, hydrostatic test report, ultrasonic & X-ray nondestructive test report, 3LPE coating thickness test report, UV aging test report, and support third-party inspections such as SGS, BV, TUV as required by customers.

Q5: What is your production and delivery cycle?

Conventional size API 5L X70 3LPE LSAW pipes are in stock with 3-7 days fast delivery. For customized non-standard specifications and large-order bulk goods, the production cycle is 15-25 days. We support flexible logistics methods including sea freight, land freight and container transportation to ensure timely delivery.

Q6: How to ensure the anti-corrosion coating is not damaged during transportation?

We adopt full-process protective packaging: pipe end anti-collision caps, overall waterproof and scratch-resistant wrapping, fixed steel strapping and container anti-slip cushioning measures. Professional loading and fixed transportation schemes avoid coating friction, extrusion and impact damage. We have zero coating damage records in long-term export transportation.

Q7: What is the service life of 3LPE anti-corrosion steel pipe?

Under standard buried and outdoor working environment, the service life of our 3LPE coated X70 LSAW steel pipe can reach more than 50 years. The upgraded UV-stabilized coating can adapt to long-term outdoor open-air use and harsh marine corrosive environments, with far better aging resistance and corrosion resistance than ordinary anti-corrosion pipes.