Application description:

Widely used in oil and gas transmission, water supply pipelines, structural supports (piles, columns), piling for construction, industrial piping, chemical plants, and power generation. Also suitable for fencing, scaffolding, and general fluid transport. ERW pipes ideal for medium diameters; LSAW pipes for large-diameter, high-pressure applications.

Production description

For ERW (electric resistance welding): Steel coil is slit, roll-formed into tubular shape, and welded longitudinally by high-frequency current. The weld seam is then heat treated and sized to final diameter. The pipe is cut, straightened, and inspected.

For LSAW (longitudinal submerged arc welding): Steel plate is edge-prepared, formed into a U-shape and then O-shape (UOE process), or formed by JCOE, then welded from inside and outside using submerged arc welding. The weld is inspected by X-ray or ultrasonic, expanded for roundness, and tested hydrostatically.

Both processes produce a straight weld seam along the pipe length. Pipes are then beveled, coated if required, and packed.

Shipping Packaging

For export, longitudinal welded pipes are bundled with plastic end caps, wrapped in VCI paper and moisture-proof polyethylene, packed in wooden crates or on ISPM-15 pallets (large pipes may be shipped loose with protective wrapping), secured with steel straps, and fitted with edge protectors. Labels include grade, size, length, quantity, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength:Direct manufacturer with advanced ERW and LSAW production lines (UOE, JCOE), capable of producing pipes from 21.3mm to 1422mm OD, ensuring consistent weld quality, dimensional accuracy, and high production efficiency.

2.Quality Assurance:Strict control of chemical composition, mechanical properties, and dimensional tolerances (OD ±0.5%, wall ±0.2mm); 100% hydrostatic testing and ultrasonic/X-ray weld inspection; compliant with ASTM A53/A135, API 5L, EN 10217, GB/T 3091.

3.Certifications & Reports:Mill test certificates (MTC) with each shipment; third-party inspections (SGS, BV, DNV) and NDT reports (UT, RT) available upon request.

4.Customization & Service:Wide range of carbon steel (GR.B, X42–X70, S235–S355) and alloy steel (15CrMo, 4130), OD 21.3–1422mm, wall 1.0–60mm, custom lengths, end finishes (plain, beveled, threaded, grooved), and coatings (3PE, galvanized, FBE) with fast lead times.

5.Export Packaging:Plastic end caps + VCI paper + moisture-proof wrapping + wooden crates/ISPM-15 pallets (or loose with protective wrapping for large OD) + steel strapping + edge protectors for safe sea freight and damage-free delivery.

FAQ

1. What is the difference between ERW and LSAW pipes?

ERW pipes are made from steel coil with high-frequency welding, suitable for small to medium diameters (21.3–610mm) and thin walls. LSAW pipes are made from steel plate with submerged arc welding, suitable for large diameters (406–1422mm) and thick walls, offering higher pressure capacity and better weld integrity.

2. Can you supply pipes with anti-corrosion coating?

Yes. We offer 3PE, FBE, galvanized, or black paint coating. Coating type and thickness can be customized based on your service environment (underground, offshore, or industrial).

3. How do you ensure weld seam quality for longitudinal welded pipes?

We perform 100% hydrostatic testing on every pipe. For LSAW pipes, we also conduct 100% ultrasonic testing (UT) and X-ray (RT) on the weld seam. For ERW pipes, online eddy current or ultrasonic testing is applied. Third-party inspection (SGS, BV) is available.