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LSAW steel pipes, or Longitudinally Submerged Arc Welded steel pipes, are manufactured using a longitudinal welding process. This technique involves cold-forming thick steel plates into the desired shape and then welding them using the submerged arc welding method. LSAW pipes are known for their high strength, large diameter, and thick walls, making them suitable for demanding applications.
LSAW pipes are primarily used for transporting fluids and gases and for structural purposes. They are commonly employed in the transportation of liquids and gases, such as oil, natural gas, water, and sewage. These pipes are also used in construction for piling and structural support, as well as in various industrial applications where high mechanical strength and corrosion resistance are necessary.
| Standard | Description | Grades |
| API 5L | Standard for steel pipes used in oil and gas pipelines. | Grade A, B; X42, X46, X52, X56, X60, X65, X70, X80, X90, X100, X120 |
| ASTM A252 | Standard for welded and seamless steel pipe piles. | Grade 1, Grade 2, Grade 3 |
| ASTM A139 | Standard for electric-fusion (arc)-welded steel pipes. | Grade A, Grade B, Grade C, Grade D |
| EN 10219 | Standard for cold-formed welded structural hollow sections. | S235, S275, S355, etc. |
| EN 10217 | Standard for welded steel tubes for pressure purposes. | P235, P265, P355, etc. |
| GB/T 9711 | Chinese standard for steel pipes in oil and gas pipelines. | L245, L290, L320, L360, L390, L415, L450, L485, L555, etc. |
| GB/T 3091 | Standard for welded steel pipes for low-pressure fluid conveyance. | Q195, Q215, Q235, Q295, Q345, etc. |
| ISO 3183 | International standard for steel pipes in pipeline transportation systems. | L245, L290, L360, L415, L450, etc. (similar to API 5L) |
| JIS G3444 | Japanese standard for carbon steel tubes for structural purposes. | STK400, STK490, STK500, etc. |
| JIS G3457 | Japanese standard for arc-welded carbon steel pipes. | STPY400, STPY410, etc. |
| DIN 2458 | German standard for welded steel tubes. | St35, St45, St52, etc. |
| Types | Standard | |||||
| SY/T5040-2000 | SY/T5037-2000 | SY/T9711.1-1977 | ASTM A252 | AWWA C200-97 | API 5L PSL1 | |
| Tube end OD deviation | ±0.5%D | ±0.5%D | -0.79mm～+2.38mm | <±0.1%T | <±0.1%T | ±1.6mm |
| Wall thickness | ±10.0%T | D<508mm, ±12.5%T | -8%T～+19.5%T | <-12.5%T | -8%T～+19.5%T | 5.0mm<t<15.0mm, ±0.11 |
| D>508mm, ±10.0%T | T≥15.0mm, ±1.5mm | |||||
| Standard | Grade | Chemical Composition(max)% | Mechanical Properties(min) | |||||
| C | Mn | Si | S | P | Yield Strength(Mpa) | Tensile Strength(Mpa) | ||
| GB/T700-2006 | A | 0.22 | 1.4 | 0.35 | 0.05 | 0.045 | 235 | 370 |
| B | 0.2 | 1.4 | 0.35 | 0.045 | 0.045 | 235 | 370 | |
| C | 0.17 | 1.4 | 0.35 | 0.04 | 0.04 | 235 | 370 | |
| D | 0.17 | 1.4 | 0.35 | 0.035 | 0.035 | 235 | 370 | |
| GB/T1591-2009 | A | 0.2 | 1.7 | 0.5 | 0.035 | 0.035 | 345 | 470 |
| B | 0.2 | 1.7 | 0.5 | 0.03 | 0.03 | 345 | 470 | |
| C | 0.2 | 1.7 | 0.5 | 0.03 | 0.03 | 345 | 470 | |
| BS En10025 | S235JR | 0.17 | 1.4 | - | 0.035 | 0.035 | 235 | 360 |
| S275JR | 0.21 | 1.5 | - | 0.035 | 0.035 | 275 | 410 | |
| S355JR | 0.24 | 1.6 | - | 0.035 | 0.035 | 355 | 470 | |
| DIN 17100 | ST37-2 | 0.2 | - | - | 0.05 | 0.05 | 225 | 340 |
| ST44-2 | 0.21 | - | - | 0.05 | 0.05 | 265 | 410 | |
| ST52-3 | 0.2 | 1.6 | 0.55 | 0.04 | 0.04 | 345 | 490 | |
| JIS G3101 | SS400 | - | - | - | 0.05 | 0.05 | 235 | 400 |
| SS490 | - | - | - | 0.05 | 0.05 | 275 | 490 | |
| API 5L PSL1 | A | 0.22 | 0.9 | - | 0.03 | 0.03 | 210 | 335 |
| B | 0.26 | 1.2 | - | 0.03 | 0.03 | 245 | 415 | |
| X42 | 0.26 | 1.3 | - | 0.03 | 0.03 | 290 | 415 | |
| X46 | 0.26 | 1.4 | - | 0.03 | 0.03 | 320 | 435 | |
| X52 | 0.26 | 1.4 | - | 0.03 | 0.03 | 360 | 460 | |
| X56 | 0.26 | 1.1 | - | 0.03 | 0.03 | 390 | 490 | |
| X60 | 0.26 | 1.4 | - | 0.03 | 0.03 | 415 | 520 | |
| X65 | 0.26 | 1.45 | - | 0.03 | 0.03 | 450 | 535 | |
| X70 | 0.26 | 1.65 | - | 0.03 | 0.03 | 585 | 570 | |
1. Pipe Type:
LSAW Steel Pipe, Longitudinally Submerged Arc Welding Pipe. DSAW Steel Pipe, Welded Steel Pipe
2. Diameter:
LSAW pipes are typically manufactured in large diameters, ranging from 16 inches (406 mm) to 60 inches (1524 mm) or more.
3. Wall Thickness:
The wall thickness generally ranges from 6 mm to 40 mm, making them suitable for high-pressure and heavy-load applications.
4. Length:
Standard lengths are usually 6 meters to 18 meters, but custom lengths can be produced based on project requirements.
5. Material: LSAW pipes are made from carbon steel, low-alloy steel, or high-strength steel.
Grades: Common grades include:
API 5L Grades: Such as A, B, X42, X52, X60, X65, X70, X80 (used for oil and gas pipelines).
ASTM A53: For general-purpose applications.
ASTM A252: For piling purposes.
EN 10219: For structural purposes.
GB/T 9711: For oil and gas pipelines (Chinese standard).
6. Surface Treatment:
Bare Pipe: No treatment, for non-corrosive environments.
Anti-Corrosion Coatings: 3LPE, FBE, coal tar enamel, galvanization.
Internal Coatings: For corrosive fluids, like epoxy coatings.
7. End Type:
Square Ends/Plain Ends (straight cut, saw cut, torch cut), Beveled/Threaded Ends
8. High Strength:
Suitable for high-pressure applications.
9. Large Diameter:
Ideal for large-capacity fluid and gas transport.
10. Precision Welding:
The longitudinal seam is welded using the submerged arc welding process, ensuring high-quality and reliable welds.
11. Cost-Effective:
Ideal for large-diameter applications due to lower production costs compared to seamless pipes.
1. Raw Material Preparation: Thick steel plates are used as the raw material.
2. Edge Preparation: The edges of the steel plate are prepared for welding.
3. Forming: The steel plate is formed into a cylindrical shape using a series of bending operations.
4. Welding: Longitudinal welding is performed using the submerged arc welding method
5. Post-Welding Processes: Depending on the specific type (e.g., UOE or JCOE), the pipe may undergo additional processes such as Uing, Oing, and expanding to achieve the desired dimensions and mechanical properties.
6. Inspection and Testing: The final product is inspected and tested to ensure it meets quality standards.
Pipeline Transportation: LSAW pipes are extensively used for transporting oil, natural gas, and other hydrocarbons due to their high-pressure capabilities and corrosion resistance.
Offshore Platforms: Used in offshore oil and gas platforms for structural support and fluid transportation.
Water Supply: LSAW pipes are used for large-diameter water supply pipelines, ensuring reliable and durable transportation of water over long distances.
Sewage Systems: They are also used in sewage systems where corrosion resistance and high strength are crucial.
Piling: LSAW pipes are used as piles in construction projects due to their high load-bearing capacity and corrosion resistance.
Structural Support: Used in bridges, tunnels, and other infrastructure projects for their strength and durability.
Chemical and Petrochemical Plants: LSAW pipes are used in chemical and petrochemical plants for transporting various fluids and gases.
Power Plants: Used in power plants for transporting water, steam, and other fluids.
