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Product Description

Produced by forming steel coil or plate into a tubular shape and welding the longitudinal seam using high-frequency ERW (for small to medium diameters) or submerged arc welding LSAW (for large diameters). Features uniform wall thickness, good dimensional accuracy, smooth weld seam, and cost-effective production. Available materials: carbon steel (Q195, Q235, Q345, Q355, S235JR, S355JR, ST37, ST52, GR.B, X42–X70) and alloy steel (15CrMo, 12Cr1MoV, 4130). Outer diameter: ERW (21.3mm – 610mm), LSAW (406mm – 1422mm). Wall thickness: ERW (1.0mm – 20mm), LSAW (6mm – 60mm). Length: 3m – 12m or custom. Surface finish: black (as-welded), pickled & oiled, 3PE coated, galvanized, or anti-corrosion paint. End finish: plain, beveled, threaded, or grooved. Manufacturing: ERW for small/medium OD, LSAW for large OD with single or double straight seam. 100% hydrostatic or ultrasonic testing. Meets ASTM A53/A135, API 5L, EN 10217, JIS G3452/G3444, or GB/T 3091 standards.

Parameter

Product name	Welded round steel pipe
Standard	AISI,ASTM,DIN,JIS,GB ,JIS,SUS,EN,etc
Grade	SS400, Q235, Q345, Q460, A572 Gr.50, A572 Gr.60, S235, S275, S355, Grade A/B, X42, X52, X60, X70, GB/T 3091, GB/T 13793, ASTM A252, ASTM A53, ASTM A500, EN 10210, EN 10219, API 5L, DIN 1626/1615, DIN 17120, API5L, ASTM A106 Gr.B, ASTM A53 Gr.B, ASTM A270, ASTM A249, ASTM A511, ASTM A778 , ASTM A312, ASTM A358, ASTM A409, ASTM A213, ASTM A790, ASTM A268, ASTM A269, ASTM A554, ASTM B338, ASTM B673, ASTM B674, ASTM B677, ASTM B675, ASTM B676, ASTM B690, ASTM A928, ASME B36.19, ASMEB36.10, ASTMA179/ A192/ A213/ A210/ 370WP91, WP11, WP2 GB5310-2009, GB3087-2008, GB6479-2013, GB9948-2013, GB/T8163-2008, GB8162-2008, GB/T17396-2009 etc.
Technique	Hot Rolled, ERW, Cold Rolled
Outer diameter	16mm-2000mm (0.62''-78.7'') diameter can be manufactured as cutomer require
Wall thickness	0.7mm-26mm (0.02''-1.02'') wall thickness can be manufactured as cutomer require
Length	as customer needs
Surface Treatment	black paint,varnish,oil,galvanized,anti-corrosion coated
Pipe ends	plain ends, beveled ends etc
Application	oil/gas/water fluid transportation or construction, hydraulic precision machinery parts/ power/ boiler/ petrochemical/ building industry etc

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.

Customer Reviews

FACTORY APPEARANCE

HONORS AND QUALIFICATIONS

The company has sufficient inventory and complete varieties and specifications. Special materials and specifications are produced according to customer requirements and exported to Asia, the Middle East, Europe and other countries and regions. We have our own quality management systems: ISO9001, ISO14000, OHSAS18001 standards.

Electromagnetic Compatibility and Low Voltage Directive Certification

ABS Classification Society Certification Certificate

Quality Management System Certification Certificate 2

IATF 16949 Quality Management System Certification Certificate

API Q1 Quality System Certification Certificate

CCS Classification Society Certification Certificate

CUSTOMER VISIT

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We understand that our customers value quality and after-sales service most. We consistently adhere to high standards and strict requirements, striving to become your preferred partner.

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Welded Steel Pipe