rades & Standards: API 5L B–X90 (PSL1/PSL2), GB/T 9711, ISO 3183, ASTM A252, DNV-OS-F101, NACE MR0175.
Wall Thickness: 6–25.4 mm, lengths up to 18.5 m.
Manufacturing: Spiral forming from coil, double-sided SAW welding, hydro-static + NDT (UT/RT) testing.
Key Benefits: Excellent stress distribution, fast production, flexible dimensions, suits piling & low-to-medium pressure lines.
Coatings Available: 3LPE/3LPP, FBE, internal epoxy, CWC, PU insulation — full protection for buried, sub-sea, or potable water.
SSAW pipe, also known as Spiral Submerged Arc Welded pipe, is made from steel coils and formed into a helical seam with double-sided submerged arc welding, providing robust structural strength and good stress distribution for large-diameter pipe needs. It delivers economical and reliable performance in oil and gas transport, water infrastructure, and construction. Octal Steel offers SSAW pipes in diameters from 20 in to 64 in (508 mm to 1626 mm), wall thicknesses from 6 mm to 25.4 mm, and grades such as API 5L Grade B to X90. Featuring customizable coatings like 3LPE or FBE, beveled or plain ends, and lengths up to 18.5 m, our pipes suit onshore and offshore pipelines, providing long-term durability through state-of-the-art production and thorough testing.
Octal Steel’s SSAW pipes conform to key international and domestic standards, ensuring suitability for fluid conveyance and structural roles. Core specifications encompass:
API SPEC 5L (PSL1 and PSL2): Line pipes for petroleum and natural gas, with PSL2 including advanced testing for Charpy V-notch (CVN) impact, hydrogen-induced cracking (HIC), and sulfide stress cracking (SSC) in sour service.
GB/T 9711-2017: Steel pipes for pipeline systems in oil and gas industries, spanning grades L245/B to L625/X90.
ISO 3183: Global standard for steel pipes in petroleum and natural gas sectors, synchronized with API 5L.
ASTM A252: Welded steel pipe piles for foundational and structural support.
SY/T 5037-2018: Submerged arc welded pipes for general fluid transport.
DNV-OS-F101: Offshore guidelines for submarine pipelines.
Supplementary standards: EN 10219 for cold-formed welded structural sections, CSA Z245.1 for Canadian applications, and NACE MR0175/ISO 15156 for H2S environments.
Products include mill test certificates (MTC) per EN 10204 3.1 or 3.2, covering chemistry, mechanics, and NDT. Third-party verifications from SGS or BV guarantee traceability.
SSAW pipes are widely applied in scenarios demanding large diameters and economical strength:
Oil and Gas Transportation: Onshore trunk lines for crude and natural gas, handling pressures up to 80 bar with sour-resistant grades in regions like the Middle East.
Water Supply and Drainage: Municipal water networks, sewage, and irrigation systems, with epoxy linings ensuring NSF/ANSI 61 compliance for potable use.
Structural and Civil Engineering: Pipe piles for bridges, docks, and high-rises, distributing loads effectively in foundations.
Offshore and Marine Projects: Sub-sea flow-lines with CWC for buoyancy control, resisting currents in Gulf or North Sea installations.
Chemical and Industrial Slurries: Mining tailings or chemical transport, where abrasion-resistant coatings protect against erosive media.
Agricultural and Utility Infrastructure: Large-scale water diversion or district heating, with insulation for thermal efficiency.
SSAW pipes at Octal Steel utilize premium steel coils (e.g., Q235, Q345, API 5L materials), with compositions engineered for optimal weldability, ductility, and resistance to environmental stresses. Grades like API 5L X60 excel in high-pressure scenarios.
| Grade | C max (%) | Mn max (%) | P max (%) | S max (%) | Yield Strength min (MPa) | Tensile Strength min (MPa) | Elongation min (%) |
|---|---|---|---|---|---|---|---|
| API 5L Grade B (PSL1) | 0.28 | 1.20 | 0.030 | 0.030 | 245 | 415 | 27 |
| API 5L X52 (PSL2) | 0.24 | 1.40 | 0.025 | 0.015 | 360 | 460 | 22 |
| API 5L X60 (PSL2) | 0.24 | 1.40 | 0.025 | 0.015 | 415 | 520 | 20 |
| API 5L X70 (PSL2) | 0.24 | 1.40 | 0.025 | 0.015 | 485 | 570 | 18 |
| GB/T 9711 L360 | 0.22 | 1.60 | 0.025 | 0.015 | 360 | 510 | 20 |
These attributes allow operation from -20°C to 100°C, with PSL2 variants undergoing CVN testing (≥27 J at 0°C) for enhanced toughness.

Octal Steel’s SSAW pipe fabrication leverages automated, high-efficiency lines, grouped into major phases for consistent quality:
Raw Material Preparation
Steel coils (Q235/Q345/API 5L) arrive for inspection, verifying defects, chemistry, and dimensions. Uncoiling follows, with edge milling to form precise bevels (e.g., 30° angles) for seamless welding preparation.
Spiral Forming
Coils are continuously bent into a helical shape using forming machines, creating the pipe body with controlled seam angles for optimal stress distribution and roundness.
Welding and Seam Treatment
Double-wire submerged arc welding (SAW) secures internal and external seams under flux, achieving deep fusion. Post-weld, slag is removed, and heat treatment (annealing/normalizing) relieves stresses for uniform properties.
Testing and Finishing
Comprehensive NDT includes 100% ultrasonic testing (UT) and radiographic testing (RT) on seams, plus hydrostatic pressure tests to confirm integrity. Dimensional checks ensure accuracy, followed by end beveling and optional coatings like 3PE/FBE, tested for adhesion and durability.
Quality assurance runs throughout, with MTCs and optional third-party inspections (SGS/BV) validating zero defects.

| Feature | SSAW (Spiral) | LSAW (Longitudinal) | ERW (Electric Resistance) |
|---|---|---|---|
| Diameter Range | 20–100 in (best for large) | 16–64 in | 1/2–24 in |
| Wall Thickness | 6–25.4 mm | Up to 75 mm | Up to 20 mm |
| Production Cost | Lowest (continuous coil) | Highest | Medium |
| Weld Seam | Helical – even stress distribution | Single straight seam | Straight seam |
| Ovality & Straightness | Good | Excellent | Very good |
| Best Applications | Water lines, piling, low-to-medium pressure gas | High-pressure oil/gas, offshore | Small-to-medium pipelines |
| Lead Time | Fastest | Longer | Fast |
Quick Rule of Thumb: Choose SSAW when you need large diameter + cost efficiency (water, piling, onshore gas). Choose LSAW for maximum pressure and offshore strength.
Octal Steel provides complete external and internal protection systems to match any environment:
| Coating Type | Layer Structure | Thickness | Service Life | Typical Use |
|---|---|---|---|---|
| 3LPE / 3LPP | FBE + adhesive + PE/PP topcoat | 2.5–4.5 mm | 40–50+ years | Buried pipelines, onshore/offshore |
| FBE (Fusion Bonded Epoxy) | Single/dual-layer epoxy | 350–600 μm | 30+ years | Moderate temperature, water lines |
| Internal Epoxy Lining | Liquid epoxy or FBE | 300–500 μm | 30+ years | Potable water, oil, gas flowlines |
| Concrete Weight Coating (CWC) | Reinforced concrete over 3LPE | 40–150 mm | 50+ years | Subsea buoyancy control |
| Polyurethane Foam Insulation | PU foam + HDPE jacket | 50–100 mm foam | 30+ years | District heating, arctic pipelines |
All coatings are applied in-house, tested for adhesion (≥250 N/10 mm), holiday-free, and fully certified.
SSAW pipes provide unique benefits for cost-sensitive, large-scale projects, outperforming alternatives like ERW in certain scenarios:
Octal Steel distinguishes itself as a premier supplier of SSAW welded steel pipes through a commitment to quality, innovation, and customer satisfaction. Here’s why industry professionals worldwide partner with us:
Choosing Octal Steel means investing in durable, high-performance SSAW pipes from a trusted partner focused on your success.
Q1: What is SSAW Pipe used for?
A: SSAW Pipe is used for large-diameter fluid transmission (oil, gas, water) and structural piling where cost efficiency and inspection evidence are required.
Q2: Can SSAW Pipe meet API 5L requirements?
A: Yes. API 5L SSAW Pipe can be supplied in PSL1/PSL2. Confirm grade, PSL level, and any sour service requirement in the inquiry.
Q3: How do you verify pipe weld quality on SSAW Pipe?
A: The spiral seam (pipe weld) is verified through process control plus UT/RT (as required) and hydrostatic testing, supported by MTC and inspection reports.
Q4: Which coating is recommended for buried or subsea service?
A: Buried lines often use 3LPE/3LPP or FBE; subsea service commonly requires CWC. Selection depends on temperature, medium, and design life.
Q5: Can you supply documentation and third-party inspection?
A: Yes. We provide EN 10204 3.1/3.2 MTC, NDT and hydrotest records, coating reports, and can arrange SGS/BV inspection when required.