Seamless, ERW, LSAW and SSAW Pipes: The Differences Explained

Pipes are essential to many industries, including oil and gas, construction, and water supply. They carry liquids, gases, and even solids, ensuring the smooth operation of various industrial processes. Knowing the different types of pipes and their specific uses is key to choosing the right one for any project. In this article, we’ll explore four main types of pipes: Seamless, Electric Resistance Welded (ERW), Longitudinally Submerged Arc Welded (LSAW), and Spiral Submerged Arc Welded (SSAW). We’ll explain how they are made, what they are used for, and their benefits. Let’s dive into the details!

What are Seamless Pipes?

Seamless pipes are created from a solid piece of steel, known as a billet, which is pierced to form a hollow tube. This process involves heating the billet to a high temperature and then rolling and stretching it until it takes on a hollow shape. The result is a pipe without seams or welds, which makes it extremely strong and able to withstand high pressure.

Seamless pipes are commonly used in industries where high pressure, high temperature, and high corrosion resistance are crucial. These industries include oil and gas, power generation, petrochemical, and automotive. Specific use cases include drilling operations, pipeline systems, and high-pressure boiler tubes.

Advantages of Seamless Pipes

  • Durability: The absence of welded seams makes seamless pipes highly durable, reducing the risk of weak points.
  • Strength: They can withstand higher pressure and stress compared to welded pipes.
  • Corrosion Resistance: The uniform structure of seamless pipes makes them less prone to corrosion, ideal for harsh environments.

Disadvantages of Seamless Pipes

  • Cost: The complex manufacturing process makes seamless pipes more expensive.
  • Manufacturing Complexity: Producing seamless pipes requires specialized equipment and expertise, making it more challenging compared to other pipe types.

Seamless pipes are an indispensable component in industries requiring high durability, strength, and corrosion resistance. While their production is more costly and complex, the benefits they offer in demanding applications often outweigh these drawbacks.

What are ERW Pipes?

Electric Resistance Welded pipes are made by rolling a flat piece of metal into a cylindrical shape and then welding the edges together along its length. This weld is created using electrical resistance, which fuses the edges to form a strong seam. The process is efficient and cost-effective, making ERW pipes a popular choice for many uses.

ERW pipes are prevalent in low and medium pressure applications such as water and gas pipelines, fencing, scaffolding, and structural applications in construction. They are also used in the automotive industry for manufacturing exhaust pipes and other components.

Advantages of ERW Pipes

  • Cost-Effective: The manufacturing process of ERW pipes is simpler and less expensive compared to seamless pipes, making them a more budget-friendly option.
  • Efficient Production: The production process is faster and can be automated, allowing for higher production rates and quicker turnaround times.

Disadvantages of ERW Pipes

  • Size Limitations: ERW pipes are typically available in smaller diameters, which can be a limitation for certain applications requiring larger pipes.
  • Welded Seam Issues: The seam created during welding can be a potential weak point, especially under high pressure or in corrosive environments, where it may be more prone to failure.

ERW pipes are a versatile and cost-effective option for a wide range of applications, especially where lower pressure and smaller diameters are sufficient. However, their welded seam can pose challenges in more demanding environments.

What are LSAW Pipes?

Longitudinally Submerged Arc Welded pipes are created by shaping large steel plates into a cylindrical form and welding them along the length. This process allows for the production of pipes with larger diameters and thicker walls, ensuring a strong and high-quality seam.

LSAW pipes are used in high-pressure applications and for the transportation of oil and gas. They are also employed in structural applications, such as piling and in offshore and marine environments where strength and durability are critical.

Advantages of LSAW Pipes

  • High Strength: These pipes offer exceptional strength, capable of handling high pressure and stress.
  • Large Sizes: LSAW pipes can be manufactured in larger diameters, making them suitable for large-scale projects.
  • Disadvantages of LSAW Pipes
  • Higher Cost: The manufacturing process is more complex and expensive, leading to higher costs for LSAW pipes.
  • Production Challenges: Making these pipes requires advanced machinery and skilled workers, adding to the complexity of production.

Despite their higher cost and production challenges, LSAW pipes are a reliable choice for projects that demand strong, large-diameter pipes.

What are SSAW Pipes?

Spiral Submerged Arc Welded pipes are made by welding strips of steel in a spiral pattern to form a cylindrical shape. This welding is done using a submerged arc welding process, which ensures a strong seam along the spiral. This method allows for flexibility in the pipe’s diameter and wall thickness.

SSAW pipes are commonly used for transporting water, gas, and other fluids over long distances. They are also used in construction for structural purposes and in the oil and gas industry for pipeline systems.

Advantages of SSAW Pipes

  • Flexibility in Diameter: SSAW pipes can be produced in a wide range of diameters, making them suitable for various applications.
  • Cost-Effective: The production process is efficient and generally less expensive than other methods, such as seamless or LSAW pipes.

Disadvantages of SSAW Pipes

  • Potential for Defects: The spiral weld can be prone to defects if not executed correctly, which can affect the pipe’s integrity.
  • Structural Issues: SSAW pipes might not be as strong as seamless or LSAW pipes, especially under high pressure.

SSAW pipes offer versatility and cost-effectiveness for many applications, though they may face challenges related to weld quality and structural strength in high-pressure environments.

Comparison of Seamless, ERW, LSAW, and SSAW Pipes

Each type of pipe has unique features that make it suitable for different uses. Seamless pipes are great for high-pressure and high-temperature settings but tend to be more expensive. ERW pipes are cost-effective and efficient to produce, though they are usually limited to smaller diameters. LSAW pipes are strong and can be made in large diameters, but their production is complex and costly. SSAW pipes offer flexibility in size and are economical, but they might have defects and aren’t as strong under high pressure.

How to Choose the Right Pipe for Your Project

When picking the right pipe for your project, think about the pressure and temperature requirements, budget, and the needed size and thickness. Here’s a quick guide:

  • Seamless Pipes: Choose these for high-pressure and high-temperature situations. They’re strong and reliable but can be more expensive.
  • ERW Pipes: These are great for low to medium pressure applications. They are budget-friendly and efficient to produce, but usually come in smaller sizes.
  • LSAW Pipes: Ideal for big projects that need extra strength. They can handle large diameters but are more costly and complex to make.
  • SSAW Pipes: These offer flexibility in size and are economical. They’re good for a variety of uses but might not be the best under very high pressure.


Understanding the differences between seamless, ERW, LSAW, and SSAW pipes is essential for choosing the right one for your project. Each type has its own strengths and weaknesses, making them ideal for different uses. By thinking about factors like cost, strength, and how complicated they are to make, you can pick the pipe that best fits what you need.

At UNIACERO, we are dedicated to providing the steel pipe solutions you need for any project. We proudly offer a wide range of high-quality steel products, including seamless, ERW, LSAW, and SSAW pipes. In addition, we offer financing and delivery services, ensuring a comprehensive solution for our customers.

If you’re looking for steel pipes, get in touch with us. Our friendly team is ready to guide you through every step of the process.

Call +86 (022) 8837 8999 or email us today.

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