China LSAW Steel Pipe Manufacturer: Specifications, Process & Applications

What is LSAW Pipe (Longitudinal Submerged Arc Welded Pipe)?

LSAW Pipe = Longitudinal Submerged Arc Welded Pipe. In the steel pipe industry, it is also known as JCOE Pipe.

LSAW steel pipes are manufactured by bending steel plates into a tubular shape and then welding a longitudinal seam using submerged arc welding (SAW).

The JCOE forming process is currently the most widely used; it involves sequentially pressing the steel plate into “J,” “C,” and “O” shapes before finally welding it into the final form.

Thanks to its high strength and reliability, LSAW pipe is widely used in oil and gas transportation, engineering structures, and large-diameter water transmission trunk lines.

Key Features and Advantages of LSAW Steel Pipe

As a professional supplier of high-end steel products, CORTEC STEEL LIMITED offers LSAW steel pipes with outer diameters ranging from 406 to 1626 mm and wall thicknesses from 6 to 75 mm.

High-Quality Weld Seam

LSAW steel pipes are manufactured using the submerged arc welding (SAW) process, resulting in high-quality, uniform, and dense welds.

CORTEC STEEL LIMITED performs 100% non-destructive testing (NDT, such as UT/RT) on the steel pipes.

Large Diameter Capability

LSAW steel pipes are primarily used for medium- and large-diameter steel pipes, typically with specifications of DN400 or larger.

They are particularly well-suited for long-distance transmission pipelines, effectively improving transportation efficiency.

Thick Wall Pipe

LSAW steel pipes can be manufactured with heavy wall thicknesses, making them suitable for high-pressure, low-temperature, and corrosive environments.

High Strength & Reliability

The raw material for LSAW steel pipe is typically steel plate, which allows for strict quality control. As a result, its weldability is similar to that of the base material.

LSAW welds are straight and free of helical stresses, offering higher and more uniform strength, making them suitable for demanding engineering applications.

High Standard Applications

The LSAW steel pipes supplied by CORTEC STEEL LIMITED comply with various international standards, including API 5L, EN 10219 / EN 10210, and ASTM A252, to meet the requirements of diverse projects.

Good Welding Consistency

Compared to submerged arc welded spiral pipes (SSAW), LSAW steel pipes feature a straight-seam construction, which facilitates quality control.

LSAW steel pipes feature a high degree of automated welding. After undergoing mechanical expansion, they exhibit low and uniformly distributed internal stresses, ensuring consistent dimensional accuracy.

LSAW Pipe Specifications and Size Range

LSAW steel pipes are primarily used for medium to large diameters:

Common outer diameter range: 406–1,626 mm; 16”–64”

Maximum diameter: 1,829 mm or larger (for certain custom orders).

Standard wall thickness: 6 mm – 40 mm

In high-pressure oil and gas projects, the wall thickness is typically ≥ 12.7 mm.

Standard wall thickness: 6 mm – 40 mm

In high-pressure oil and gas projects, the wall thickness is typically ≥ 12.7 mm.

Length range: Standard lengths: 6 m / 12 m

Common delivery lengths: 11.8 m / 12.2 m (for ease of container/sea transport)

CORTEC STEEL LIMITED can flexibly customize products to meet project requirements.

Typical LSAW Steel Pipe Size

DN LSAW Specification Reference Range

Dimensional Tolerance Standards

Manufacturing Process of LSAW Steel Pipe (Step-by-Step)

LSAW pipes are manufactured using a process that combines steel plate forming with straight-seam submerged-arc welding, and are primarily used in large-diameter, high-strength pipelines.

JCOE is currently the most widely used LSAW steel pipe production process internationally.

1. Steel Plate Selection

The raw material is typically hot-rolled steel plate. Commonly used steel grades include API 5L B, X42, X52, X60, X70, and X80.

2. Plate Preparation

The steel plates undergo 100% ultrasonic testing to ensure the raw materials are free of internal defects. The plates are then edge-milled to create a groove suitable for welding.

3. Forming Process

Common forming methods for LSAW include JCOE, UOE, and RBE, with JCOE being the most widely used.

The process begins by pressing the steel plate into a J-shaped pre-bend, followed by a C-shape, and finally into a circular shape.

This step-by-step, progressive process results in a relatively uniform stress distribution in the steel, making it suitable for large-diameter, thick-walled pipes.

4. Tacking & Alignment

The pipe ends are aligned, tack-welded on the inner and outer sides, and then subjected to a double-sided submerged arc welding process.

This process uses multi-wire welding, resulting in high penetration depth, high weld strength, and stable forming.

5. Hydro or Mechanical Expansion

The welded steel pipes undergo a mechanical expansion process.

This step serves two critical purposes: improving the dimensional accuracy of the steel pipes and eliminating internal stresses.

6. NDT Inspection

Before shipment, every steel pipe undergoes 100% quality inspection of both the welds and the base metal.

Ultrasonic and X-ray technologies are used to ensure the quality of the welds and verify that the interior is free of defects such as porosity and cracks.

Applications of LSAW Pipe

Due to their large diameters, high strength, and ability to accommodate thick walls, LSAW steel pipes are widely used in the energy, infrastructure, and engineering structures sectors.

1. Oil and Gas Pipeline

This is the core application area for LSAW pipes. Common steel grades include API 5L X52, X60, X65, X70, X80, etc.

LSAW pipes offer high-pressure load-bearing capacity and high reliability, making them ideal for long-distance pipelines.

2. Offshore and Subsea Engineering

LSAW pipes are often used with 3LPE, 3LPP, or FBE coatings. They can withstand the high pressure and seawater corrosion of deep-sea environments and possess high toughness.

3. Water Transmission and Municipal Engineering

LSAW pipes feature large diameters and high flow rates, ensuring excellent water transmission efficiency.

They are relatively cost-effective and suitable for cost-sensitive projects.

4. Power Plant & Industrial Pipelines

LSAW pipes offer stable forming and good pressure resistance.

Additionally, wall thickness specifications can be customized to flexibly adapt to project requirements.

5. Structural Applications

These projects require high load-bearing capacity and excellent weldability.

LSAW pipes not only meet these requirements but also offer high dimensional accuracy, minimizing discrepancies between theoretical and actual measurements.

How to Choose a Reliable LSAW Steel Pipe Manufacturer

When selecting a reliable LSAW steel pipe manufacturer, the key is to evaluate its quality system, production capability, and project experience.

1. Required certifications

This is the most critical reference point. Some fundamental certifications include:

API 5L, the most essential certification for oil and gas pipelines.

ISO 9001, a quality management system certification.

Depending on the project’s target market, verify whether CE (European Union) certification or classification society certifications (such as ABS, CCS, or DNV) are required.

2. Quality Control / QA System

When selecting a reliable manufacturer, priority should be given to those that use the JCOE or UOE forming processes and double-sided submerged arc welding (SAW) technology. This is key to ensuring weld quality.

In addition, the manufacturer must have quality inspection equipment and must conduct rigorous testing and control of welds and dimensions.

Buyers may request that suppliers provide material certificates and test reports (MTC, Mill Test Certificate, EN 10204 3.1/3.2) to clearly document the origin of the steel pipes, as well as their chemical composition and performance specifications.

3. Production Capabilities & Project References

When selecting a manufacturer, focus on whether their production capabilities cover sizes ranging from 16” to 64”+, and whether they are capable of producing thick-walled products.

You should also review the manufacturer’s past project experience, such as in oil and gas pipelines or offshore projects.

This helps confirm whether the manufacturer is familiar with the relevant technical specifications and documentation processes, thereby reducing communication costs.

Why Choose Us as Your China LSAW Steel Pipe Supplier

CORTEC STEEL LIMITED maintains a comprehensive certification system covering API 5L, ISO 9001 / ISO 45001 / ISO 18001, EN 10219, CNAS, and more.

We meet the core API 5L requirements for LSAW pipes and are capable of supporting PSL1 and PSL2 projects.

The most critical aspect of LSAW is weld quality. CORTEC STEEL LIMITED maintains strict control over weld quality and ensures material traceability.

Choose CORTEC STEEL LIMITED for the fastest delivery times. We offer a full lifecycle solution—manufacturing, processing, and project management—to meet all your needs under one roof.

Our team of professional engineers is here to assist you at CORTEC STEEL LIMITED.

FAQ About LSAW Pipe

Q:What is the difference between LSAW and SSAW pipe?

A:LSAW pipe features a longitudinal weld and is suitable for thick-walled steel pipes. It offers consistent weld quality and is suitable for high-pressure applications.

SSAW pipe features a spiral weld and can be produced in extra-large diameters. However, it has slightly lower strength and longer welds, making it suitable for medium- and low-pressure applications.

Q:Is LSAW pipe suitable for high-pressure pipelines?

A:Yes.It is one of the mainstream choices in the oil and gas industry. Its straight-seam structure and wide range of wall thicknesses make it well-suited for pressure-bearing applications.

Available steel grades include API 5L X60, X65, X70, and X80, which inherently possess high strength and toughness, as well as excellent crack resistance.

Q:What coating options are available for LSAW pipes?

A:Options can be selected based on specific operating conditions.

External coatings: 3LPE (Three-Layer Polyethylene), 3LPP (Three-Layer Polypropylene), FBE (Fusion-Bonded Epoxy), Coal Tar Epoxy

Internal coatings: Liquid Epoxy, Cement Mortar Lining, Internal FBE.