DSAW Pipe

DSAW Pipe

High-strength Welded Pipe For Demanding Applications

Dsaw pipe offers high-strength, durable solutions for oil and gas pipelines, water transmission, and structural applications with superior weld quality.

DSAW Pipe

High-strength Welded Pipe For Demanding Applications

Dsaw pipe offers high-strength, durable solutions for oil and gas pipelines, water transmission, and structural applications with superior weld quality.

DSAW Pipe
Double Submerged Arc Welded Pipe
LSAW Steel Pipe

DSAW Pipe (Double Submerged Arc Welded Pipe) is a high-quality welded steel pipe produced using a double-sided submerged arc welding process, ensuring exceptional strength and durability. Available in Longitudinal Submerged Arc Welded (LSAW) and Spiral Submerged Arc Welded (SSAW) configurations, DSAW pipes are designed for high-pressure applications in oil and gas pipelines, water transmission, and structural projects, adhering to standards like API 5L, ASTM A252, and ASME B36.10.

The manufacturing process involves forming steel plates or coils into cylindrical shapes, with V-shaped grooves prepared on both interior and exterior surfaces for welding. A single pass of submerged arc welding on both sides, protected by flux, ensures 100% weld penetration, creating a robust and reliable bond. DSAW pipes are available in diameters from 4 inches to 167 inches (100 mm to 4267 mm) and wall thicknesses from 3/32 inch to 4 inches (2.1 mm to 100 mm), making them suitable for large-diameter and thick-walled applications.

DSAW pipes undergo stringent quality control, including ultrasonic testing, hydrostatic testing, and non-destructive examinations, to ensure defect-free welds and compliance with industry standards. Protective coatings such as 3LPE, galvanizing, or Fusion Bonded Epoxy (FBE) enhance corrosion-resistant DSAW pipe performance in harsh environments like offshore pipelines or chemical processing plants. Available in lengths up to 155 feet for spiral formats, these pipes are ideal for long-distance pipelines.

Compared to Electric Resistance Welded (ERW) or seamless pipes, DSAW pipes offer superior weld quality and dimensional accuracy, making them ideal for large-diameter, high-pressure applications such as load-bearing piles or combination wall piles. With tensile strengths starting at 415 MPa for API 5L Grade B, they provide excellent mechanical performance. Customizable end finishes (beveled, plain, or threaded) ensure compatibility with complex piping systems.

DSAW pipes address critical challenges like corrosion, high pressure, and structural stress, making them a reliable choice for engineers seeking durable industrial piping solutions for oil and gas, water supply, and construction projects. Their high weld quality and versatility ensure long-term performance in demanding conditions.

Double submerged arc welded (DSAW) spiral steel pipe is favored in industries such as oil and gas, slurry transportation, and urban construction due to its high-pressure capacity, low resistance, low-temperature resistance, corrosion resistance, and ease of installation and maintenance.

Spiral Double Welding Pipe Process

  • Double Submerged Arc Welding: Ensures uniform plate deformation, minimal residual stress, and scratch-free surfaces. Offers flexibility in producing pipes with varying diameters and wall thicknesses, especially for high-grade, thick-walled, large-diameter pipes, meeting diverse user specifications.
  • Pre-Welding and Fine Welding: Welding is performed in optimal positions, reducing defects such as misalignment, incomplete penetration, or poor weld quality, ensuring precise control.
  • Mechanical Diameter Expansion: Enhances dimensional accuracy and improves stress distribution in the steel pipe, preventing stress corrosion damage and facilitating on-site welded construction.
  • 100% Quality Inspection: Comprehensive monitoring and detection throughout the production process ensure the quality of DSAW pipes.
  • Automated Production Line: Integrated with a computer data acquisition system for real-time data transmission, centralizing control of production parameters and quality indicators.

Advantages of Double Submerged Arc Welding

Introduced in 1940, double submerged arc welding (DSAW) is a highly efficient welding method distinct from manual welding. It uses a flux system delivered through a funnel to the welding area, protecting the weld with molten flux rather than electrode coating. The continuous wire feed eliminates the need to replace electrodes, ensuring uninterrupted welding.

In DSAW, the arc burns within a cavity formed by the welding wire, base material, and flux, creating stable combustion known as submerged arc welding. Key advantages include:

  • Full Automation: Streamlines the welding process for consistency and efficiency.
  • Superior Heat Exchange and Protection: Welding under flux provides excellent heat management and high-quality welds.
  • High Current Capability: Enables high welding efficiency, ideal for large-scale projects like the West-East Gas Pipeline.

Modern advancements include double-wire and multi-wire DSAW, further enhancing efficiency for large-scale applications.

DSAW Pipe Capabilities

Our technical team provides comprehensive solutions for pipeline projects, tailored to meet system and budgetary requirements. In collaboration with partners, we offer integrated services, including:

  • Production of DSAW pipes.
  • Internal and external coating applications.
  • Double jointing for enhanced structural integrity.
  • Transportation logistics for seamless project execution.

Chemical Composition of DSAW Pipes (Typical Grades)

Chemical Composition of API 5L Grade B, ASTM A252 Grade 2, and ASTM A671
Grade C (% max) Si (% max) Mn (% max) P (% max) S (% max)
API 5L Grade B 0.28 0.45 1.20 0.03 0.03
ASTM A252 Grade 2 0.26 - 1.40 0.04 0.05
ASTM A671 0.24 0.13-0.45 0.98 0.035 0.035

The chemical composition ensures weldability, strength, and corrosion resistance for DSAW pipe in demanding industrial applications.

Mechanical Properties of DSAW Pipes (Typical Grades)

Mechanical Properties of API 5L Grade B, ASTM A252 Grade 2, and ASTM A671
Grade Tensile Strength (MPa min) Yield Strength (MPa min) Elongation (% min)
API 5L Grade B 415 245 23
ASTM A252 Grade 2 414 241 25
ASTM A671 450 240 22

These properties ensure DSAW pipes deliver robust performance in high-pressure and structural applications.

Comparison with Other Welded Pipes

DSAW Pipes (LSAW and SSAW) offer superior weld quality and large-diameter capabilities compared to other welded pipes like ERW or HFW. Below is a comparison highlighting key differences.

Comparison of DSAW Pipes with ERW and HFW Pipes
Feature DSAW Pipe (LSAW/SSAW) ERW Pipe HFW Pipe
Welding Process Double Submerged Arc Welding (inside and outside) Electric Resistance Welding High-Frequency Welding
Diameter Range 4–167 inches 1/2–24 inches 1/2–24 inches
Wall Thickness 2.1–100 mm 1.5–20 mm 1.5–20 mm
Applications Oil/gas pipelines, water transmission, structural piles Water, gas, low-pressure systems Water, oil, low-pressure systems
Weld Quality High (100% penetration) Moderate Moderate
Cost Higher (complex process) Lower Lower

Why Choose DSAW Pipes? Their superior weld quality, large diameter range, and high-pressure resistance make DSAW pipes the preferred choice for critical applications compared to ERW or HFW pipes.

Key Benefits

Superior Weld Quality

Double-sided welding ensures 100% penetration and strength.

Large Diameter Range

Available from 4 to 167 inches for diverse projects.

Corrosion Resistance

Enhanced by 3LPE, FBE, or galvanizing coatings.

High Pressure Resistance

Ideal for oil, gas, and water pipelines.

Dimensional Accuracy

Precise sizes for seamless installation.

Standards Compliance

Meets API 5L, ASTM A252, and ASME B36.10 standards.

DSAW pipes on process

DSAW pipes on process

How Are DSAW Thick-Walled

Spiral Steel Pipes Made?

Double-Sided Submerged Arc Welding (DSAW) spiral steel pipes are manufactured from strip steel coils using a precise, multi-step process to ensure strength, durability, and quality for demanding applications.

Spiral steel pipes are formed from strip steel coils, welding wires, and fluxes, which undergo strict physical and chemical testing. The process begins with butt joint welding of strip head and tail using single or double-wire submerged arc welding, followed by automatic repair welding after coiling. The strip is leveled, trimmed, planed, cleaned, and pre-bent before forming, with electric contact pressure gauges ensuring smooth conveying. Roll forming (external or internal control) and weld gap control devices maintain precise pipe diameter, alignment, and weld quality.

Welding is performed using American Lincoln electric welding machines for stable single or double-wire submerged arc welding. Welds are inspected via online continuous ultrasonic testing for 100% coverage, with defects marked and addressed. Pipes are cut into individual pieces using air plasma cutting, followed by first inspection for mechanical properties, chemical composition, weld fusion, and surface quality. Additional manual ultrasonic and X-ray inspections verify defect repairs, and X-ray television or filming checks butt welds and D-shaped joints. Each pipe undergoes a hydrostatic pressure test with radial sealing, and pipe ends are mechanically processed for precise verticality, bevel angle, and edge finish.

This rigorous DSAW process ensures spiral steel pipes meet high standards for applications in oil and gas, construction, and water pipelines, delivering robust performance and reliability.

FAQ

A DSAW pipe is a welded steel pipe made using double submerged arc welding, available in LSAW or SSAW formats, ideal for oil and gas, water transmission, and structural applications.

Carbon steel grades like API 5L Grade B, ASTM A252 Grade 2, or ASTM A671, ensuring strength and weldability.

- API 5L Grade B: C ≤0.28%, Si ≤0.45%, Mn ≤1.20%, P ≤0.03%, S ≤0.03%
- ASTM A252 Grade 2: C ≤0.26%, Mn ≤1.40%, P ≤0.04%, S ≤0.05%
- ASTM A671: C ≤0.24%, Si 0.13–0.45%, Mn ≤0.98%, P ≤0.035%, S ≤0.035%

- API 5L Grade B: Tensile ≥415 MPa, Yield ≥245 MPa, Elongation ≥23%
- ASTM A252 Grade 2: Tensile ≥414 MPa, Yield ≥241 MPa, Elongation ≥25%
- ASTM A671: Tensile ≥450 MPa, Yield ≥240 MPa, Elongation ≥22%

Diameters from 4 inches to 167 inches, wall thicknesses from 2.1 mm to 100 mm, lengths up to 155 feet for spiral formats.

Ultrasonic, hydrostatic, and non-destructive examinations ensure defect-free welds and compliance with API 5L, ASTM A252, and ASME B36.10 standards.

Oil and gas pipelines, filtration systems, refrigeration, refining, petrochemical, offshore applications, structural piles, and infrastructure projects.

3LPE, FBE, or galvanizing coatings protect against corrosion in harsh environments like offshore or chemical processing.

DSAW pipes offer superior weld quality and larger diameter ranges, making them ideal for high-pressure and large-scale applications.

API 5L, ASTM A252, ASME B36.10, and other standards upon consultation.

You Can Also Search DSAW Pipes by

Explore DSAW pipes with targeted long-tail keywords for specifications, applications, and materials.

Standards and Specifications
  • • API 5L DSAW pipe
  • • ASTM A252 double submerged arc welded pipe
  • • ASME B36.10 LSAW steel pipe
  • • DSAW pipe standards
Applications
  • • DSAW pipe for oil and gas pipelines
  • • LSAW steel pipe for water transmission
  • • Spiral welded pipe for structural piles
  • • Corrosion-resistant DSAW pipe for petrochemical industry
Material and Grades
  • • API 5L Grade B DSAW pipe
  • • ASTM A252 Grade 2 LSAW pipe
  • • ASTM A671 spiral welded pipe
  • • DSAW pipe materials
Manufacturing and Testing
  • • DSAW pipe manufacturing process
  • • Double submerged arc welded pipe production
  • • DSAW pipe testing standards
  • • Corrosion-resistant DSAW pipe quality assurance

Note: DSAW pipes meet international standards, ensuring high performance and reliability. Contact suppliers for detailed specifications.

Industrial Applications

DSAW Pipes provide robust, high-strength solutions for critical applications across a global scale, serving industries such as oil, gas, filtration, refrigeration, refining, petrochemical, and offshore, ensuring durability and reliability in demanding environments.

Oil Industry

Transports crude oil and refined products over long distances.

Gas Industry

Supports natural gas transportation in pipelines.

Filtration Industry

Used in filtration systems for fluid processing.

Refrigeration Industry

Facilitates coolant transport in refrigeration systems.

Refining Industry

Handles refined products in processing plants.

Petrochemical Industry

Transports chemicals in petrochemical facilities.

Offshore Industry

Supports offshore pipelines and structural applications.

Structural Piles

Used in load-bearing and combination wall piles.

Infrastructure

Supports bridges and heavy equipment foundations.

Why Choose DSAW Pipes? Their high weld quality, large diameter range, and corrosion resistance make them ideal for critical applications across oil, gas, filtration, refrigeration, refining, petrochemical, offshore, and infrastructure industries.

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