I. Overview of Spiral Welded Pipes
i. What are spiral welded steel pipes?
Spiral welded pipes are high-strength welded steel pipes. They are manufactured using a unique spiral forming process: steel strips are rolled and welded into a tubular shape. This process offers significant advantages.
ii.Core Manufacturing Advantages
Narrow steel strips can be used to produce pipes with extremely large diameters. The maximum diameter of spiral welded steel pipes can reach 3,000 millimeters.
Its weld seam strength typically outperforms ERW LSAW pipe.
iii. Quality Control System
The production process employs double-sided submerged arc welding technology. We adhere to 14 stringent quality inspection procedures, including:
Online ultrasonic testing (100% weld seam coverage)
Hydrostatic testing (ensuring radial seal integrity)
The quality control of this submerged arc welding steel pipe far exceeds industry standards.
iv. Application Areas
Spiral welded pipes are widely used in:
• Oil and natural gas transmission pipelines
• Infrastructure pile foundation projects
• Municipal water supply systems
• Emerging hydrogen energy pipeline networks
Their deformation resistance and corrosion resistance make them the preferred choice for critical infrastructure.
v. Procurement Decision Guidelines
Steel grade certification (e.g., Q235B/X70) must be provided
Compliance with international standards: API 5L or GB/T 9711
Manufacturers must hold certifications such as ISO 3183
II. Production Process Flow Chart for Spiral Welded Pipes
III. Application Areas of Spiral Welded Pipes
（1）Energy sector: Used in oil and natural gas transmission pipelines, as well as cooling water, steam, and flue gas emission systems in thermal power plants.
（2）Urban construction: Suitable for urban water supply and drainage pipelines, as well as pile driving pipes, bridges, docks, roads, and other supporting structures.
（3）Industrial Sector: Used in the chemical industry for transporting chemical media, and in mechanical manufacturing for producing components and equipment.
（4）Agricultural Sector: Used in agricultural irrigation systems for transporting irrigation water.
（5）Marine Engineering: Used in offshore platforms, drilling platforms, and subsea pipelines.
（6）Emerging Sectors: Also applied in the manufacturing and transportation of new energy equipment, urban wastewater treatment facilities, and other areas.
IV. Spiral Welded Pipe Procurement Risk Mitigation Guide
i. Key Points for Supplier Selection
Qualification Verification
• Verify the validity of production licenses and quality system certifications
• Qualifications for structural welded pipe suppliers ≠ requirements for spiral pipes
Performance Evaluation
• Prioritize manufacturers with a good industry reputation
Equipment and Raw Materials
• Review standardized management processes for raw materials
• Equipment for construction-grade welded pipes is not suitable for high-pressure pipeline production
ii. Contract Term Standards
Technical Parameters
• Clearly specify: diameter/wall thickness/weld height
• The ellipticity of circular welded pipes must be ≤0.6%
Payment Terms
• 30% deposit + 60% upon shipment + 10% upon inspection
Breach of Contract Clauses
• Daily penalty of 0.5% of the contract amount for delayed delivery
• Return shipping costs for quality issues are borne by the supplier
iii. Seven-step quality inspection method
Document review: Verify quality certificates and material specifications
Visual inspection: No rust on the surface/no cracks in the welds
Dimensional accuracy: Laser gauge inspection of outer diameter deviation (±0.5 mm)
Non-destructive testing: 100% ultrasonic coverage of welds
Strength testing: No cracks at 30-degree bending
Random sampling: Hardness testing + flatness inspection
Surface rating: Scratch depth ≤ 0.3mm
iv. Logistics and Warehousing Requirements
Transportation protection
• Install collision-proof rings on pipe ends
• Prohibit mixing with construction-grade welded pipes
Storage standards
• Stack height off the ground ≤ 3 layers
• Humidity control <60% RH
v. After-sales support mechanism
• 24-hour response to quality issues
• Provide welding process repair solutions
• Replacement parts for round welded pipes delivered within 48 hours
V. Spiral Welded Pipe Production Process
Raw Material Inspection → Steel Pre-Treatment → Coil Forming → Pre-Welding → Final Welding → Cooling → Sizing → Expanding → Visual Inspection → Non-Destructive Testing → Hydrostatic Testing → Corrosion Protection → Packaging and Labeling → Storage and Shipping
(1) Raw Material Inspection: Strict quality inspections are conducted on purchased steel to ensure compliance with production standards.
(2) Steel Pre-Treatment: Steel undergoes rust removal, dust removal, and other pre-treatment processes to ensure welding quality.
(3) Roll Forming: Steel is rolled into a spiral shape to form the pipe blank.
(4) Pre-Welding: The pipe blank undergoes pre-welding to ensure accurate welding positions.
(5) Precision Welding: Advanced welding technology is used to perform precise welding on the tube blanks.
(6) Cooling: The welded tubes are cooled to stabilize their performance.
(7) Sizing: The outer diameter of the tubes is adjusted to standard dimensions using sizing equipment.
(8) Expanding: The tubes are expanded to improve dimensional accuracy and roundness.
(9) Visual Inspection: The tubes are inspected for weld defects, scratches, and other issues.
(10) Non-destructive testing: Use non-destructive testing methods such as ultrasonic testing and X-ray testing to inspect the internal quality of the tubes.
(11) Hydrostatic testing: Conduct hydrostatic testing on the tubes to ensure their sealing and pressure resistance.
(12) Corrosion protection: Apply corrosion protection to the tubes as needed to enhance their corrosion resistance.
(13) Packaging and labeling: Package the qualified tubes and apply labels for convenient transportation and use.
(14) Storage and shipping: Store packaged pipes properly and arrange for shipping.
