Stainless Steel Coil Tube (Coiltube) — Wenzhou Jixing Metal Materials Co., Ltd.

Product Overview

The Stainless Steel Coil Tube (hereinafter referred to as "Coiltube") is a continuous-length tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd., designed for large-scale construction, infrastructure, and industrial applications requiring extended, seamless runs of stainless steel pipe. Unlike conventional straight-length pipe sections, Coiltube is wound onto a spool or coil, enabling transportation and deployment of extremely long continuous lengths — as demonstrated in the landmark 1800-meter horizontal coil tube installation trial using C120 high-strength high-performance concrete (HSRPC). This product eliminates the need for numerous field welds or mechanical couplings, thereby reducing joint-related failure points, minimizing construction time, and significantly enhancing structural integrity and hydraulic performance.

The Coiltube product line leverages advanced cold-drawing and cold-rolling forming technologies to produce high-precision, corrosion-resistant stainless steel tubes suitable for demanding environments including deep foundation piles, grouting conduits, geothermal systems, chemical processing, and large-scale civil engineering projects.

Material & Properties

The Coiltube is manufactured from premium-grade austenitic stainless steel, primarily utilizing the following material grades:

Key Mechanical Properties:

Specifications

Parameter Specification
Outer Diameter (OD) Φ25 mm – Φ219 mm (custom sizes available)
Wall Thickness (WT) 0.5 mm – 12 mm
Coil Length Up to 1,800 m per continuous run
Coil Inner Diameter Φ600 mm – Φ1,500 mm
Coil Weight Up to 30 tons per coil
Dimensional Tolerance (OD) ±0.10 mm (precision grade); ±0.25 mm (standard grade)
Dimensional Tolerance (WT) ±10% of nominal wall thickness
Surface Finish Mirror polished (Ra ≤ 0.4 μm), Electropolished, Brushed, or 2B finish
End Condition Plain, Beveled (45°), Threaded, or Flanged
Standard References ASTM A554, ASTM A269, EN 10217-7, GB/T 12771, JIS G3459
Delivery Condition Annealed (A), Cold-Worked (CW), Solution Annealed + Pickled (SA+P)
Applicable Standards ASME B36.19M, ISO 15765-2, DIN 17457

Manufacturing Process

The production of high-quality Stainless Steel Coiltube involves a multi-stage precision manufacturing process:

  1. Raw Material Selection & Inspection: High-purity stainless steel strip or plate is sourced from certified mills. Incoming materials undergo spectroscopic analysis (PMI — Positive Material Identification) to verify chemical composition compliance with specified grades.
  2. Coil Slitting & Edge Preparation: The master coil is slit to precise widths using high-speed slitting lines with laser-guided edge trimming. Edges are deburred and inspected for defects.
  3. Forming (Cold-Rolling / Cold-Drawing): The flat strip is progressively formed into a tubular cross-section through a series of precision roll stations. This cold-forming process imparts beneficial work-hardening, enhancing mechanical strength while maintaining dimensional accuracy.
  4. Seam Welding: The formed tube undergoes high-frequency induction welding (HFW) or orbital TIG welding to create a continuous longitudinal seam. The weld zone is ground and polished to eliminate stress concentrations and achieve surface continuity.
  5. Heat Treatment: Where required, the tube undergoes solution annealing (1050–1150°C) followed by controlled cooling to restore full austenitic microstructure and optimize corrosion resistance. Stress-relief annealing is performed for cold-worked products.
  6. Precision Sizing & Straightening: The tube passes through rotary plug sizing machines to achieve final OD and WT tolerances. Straightening ensures the tube maintains consistent geometry throughout the coil length.
  7. Surface Treatment: Depending on application requirements, the tube receives acid pickling, passivation, electropolishing, or mechanical polishing to achieve the specified surface finish and enhance passive film integrity.
  8. Coiling & Packaging: The finished tube is wound onto a steel spool using a tension-controlled coiling head to prevent deformation. Each coil is wrapped with protective film, moisture-barrier packaging, and secured with steel strapping for safe transport.
  9. Quality Control & Testing: Every production lot undergoes hydrostatic pressure testing, dimensional verification, surface inspection (eddy current and visual), and chemical analysis per applicable standards.

Applications

The Coiltube product is engineered for a wide spectrum of demanding applications:

Quality Certifications & Compliance

Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and holds the following certifications and compliance credentials:

Unique Selling Points

The Coiltube product from Wenzhou Jixing Metal Materials Co., Ltd. distinguishes itself through the following competitive advantages:

  1. Extraordinary Continuous Length Capability: Proven deployment of up to 1,800-meter continuous runs — as validated in the C120 HSRPC horizontal coil tube construction trial — dramatically reduces the number of field joints, minimizing potential failure points and accelerating installation timelines.
  2. Superior Dimensional Precision: Advanced cold-forming and rotary plug sizing technology achieves OD tolerances of ±0.10 mm, ensuring compatibility with precision-machined fittings and flanges without secondary processing.
  3. Enhanced Structural Integrity: Cold-working during the forming process imparts beneficial work-hardening, yielding 15–25% higher tensile strength compared to hot-rolled equivalents while maintaining full corrosion resistance.
  4. Multi-Grade Versatility: Comprehensive product range spanning Grades 304, 316, 321, 430, and duplex alloys (2205, 2507) accommodates the full spectrum of environmental and mechanical requirements.
  5. Integrated Surface Engineering: In-house electropolishing and passivation capabilities deliver hygienic-grade finishes (Ra ≤ 0.4 μm) directly from the production line, eliminating costly post-processing.
  6. Full Traceability & Documentation: Every coil is accompanied by complete material traceability records, including heat numbers, chemical analysis, mechanical test results, and hydrostatic pressure test certificates.
  7. Cost Efficiency: By eliminating field welding, mechanical couplings, and associated labor, Coiltube systems deliver 20–40% total installed cost savings compared to conventional straight-length pipe assemblies for long-run applications.

Technical Reference: C120 HSRPC 1800-Meter Horizontal Coil Tube Construction Trial

The landmark application of Coiltube technology in the C120 High-Strength High-Performance Concrete (HSRPC) 1800-Meter Horizontal Coil Tube Construction Technology research project demonstrated the product's exceptional capability in extreme engineering conditions. Key findings from this trial include:

This trial validates the Coiltube product as a next-generation solution for mega-infrastructure projects demanding unparalleled reliability, longevity, and construction efficiency.