LSAW vs SSAW Pipe: Key Differences

1. LSAW vs SSAW Pipe: Quick Answer

LSAW pipe uses a longitudinal weld and is generally preferred for standardized, high-pressure pipeline projects, while SSAW pipe uses a spiral weld and offers greater flexibility for large diameters and lower-cost production.

In general, LSAW is selected for tighter dimensional and pipeline requirements, while SSAW is often preferred when large diameter, production flexibility, and cost are the main priorities.

2. LSAW vs SSAW: Key Differences

LSAW and SSAW use different raw materials and forming methods, resulting in differences in weld configuration, size capability, wall thickness, production efficiency, and manufacturing cost.

Typical Applications Oil & gas transmission, water pipelines, offshore projects Water transmission, piling, infrastructure, large-diameter pipelines

3. LSAW vs SSAW: Size & Wall Thickness

LSAW and SSAW cover different pipe size and wall thickness ranges because they use different forming methods and raw materials.

SSAW generally offers a wider diameter range, while LSAW supports heavier wall thicknesses. For detailed dimensions and available wall thicknesses, see our LSAW Pipe Size Chart and SSAW Steel Pipe Sizes.

For a project requiring very large diameter, SSAW may provide more manufacturing flexibility. For heavy-wall pipe, LSAW is generally the more suitable process.

4. LSAW vs SSAW Manufacturing Process

LSAW and SSAW differ mainly in how the steel is formed before submerged arc welding. LSAW forms the pipe from steel plate into a cylindrical section, while SSAW forms a continuous spiral pipe from steel coil.

4.1 How LSAW Pipe Is Manufactured

Steel Plate → Edge Preparation → UOE / JCOE Forming → Internal & External SAW → Mechanical Expansion → Inspection

LSAW starts with a steel plate that is edge-prepared and press-formed into a cylindrical pipe body. The longitudinal seam is then welded from the inside and outside by submerged arc welding, followed by mechanical expansion to improve roundness and dimensional accuracy.

4.2 How SSAW Pipe Is Manufactured

Steel Coil → Uncoiling → Spiral Forming → Internal & External SAW → Cutting → Inspection

SSAW starts with steel coil that is continuously uncoiled and formed into a spiral pipe body. The helical seam is welded from the inside and outside by submerged arc welding, and the continuous pipe is then cut into the required lengths.

5. LSAW vs SSAW for Pressure Service

Neither LSAW nor SSAW should be selected for pressure service based on the weld configuration alone. The required design pressure, wall thickness, steel grade, weld quality, and applicable standard all affect the suitability of the pipe.

For high-pressure pipeline projects, LSAW is commonly specified because it supports heavy-wall designs and is widely manufactured to pipeline standards such as API 5L and ISO 3183. SSAW can also be used for pressure pipelines when the pipe design, welding quality, testing, and applicable standard meet the project requirements.

The forming process does not by itself determine pipe strength. Pressure capacity must be evaluated from the complete pipe specification, including OD, WT, steel grade, weld quality, design pressure, and code requirements.

Engineering Selection

For high-pressure pipeline projects, LSAW is often considered where heavy-wall construction, dimensional control, and specific pipeline standards are required. SSAW can also be used for pressure pipelines when the pipe design, welding quality, testing, and applicable standard meet the project requirements.

For water transmission and other pressure applications, both LSAW and SSAW may be suitable when the selected pipe meets the required design pressure, steel grade, testing, and applicable standard.

6. LSAW vs SSAW: Cost

The pipe type is only one part of the final purchase cost. For both LSAW and SSAW, the quoted price is mainly affected by steel grade, wall thickness, pipe length, order quantity, coating, inspection requirements, and delivery terms.

For a meaningful LSAW vs SSAW cost comparison, compare both options using the same OD, WT, steel grade, length, quantity, coating, inspection requirements, and delivery terms.

The lowest pipe price is not always the lowest project cost; delivered cost should be compared on the same technical and commercial basis.

7. FAQs

Q1. What is the main difference between LSAW and SSAW pipe?

LSAW has a longitudinal weld, while SSAW has a spiral weld. Their forming methods and typical size capabilities are different.

Q2. Can SSAW pipe be used for high-pressure applications?

Yes, provided the pipe meets the required design pressure, material, welding, testing, and applicable standard requirements.

Q3. What factors should be considered when choosing LSAW or SSAW pipe?

Key factors include pipe diameter, wall thickness, steel grade, design pressure, applicable standards, quantity, and project cost.

Q4. Can LSAW and SSAW pipe be manufactured to the same standard?

It depends on the applicable standard and project specification. The selected pipe type should be confirmed against the required manufacturing and testing requirements.