Stainless Steel Coil Tube with Rotating Probe Eddy Current Inspection
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. manufactures high-precision stainless steel coil tubes engineered for demanding industrial applications requiring superior structural integrity and defect-free performance. This product line features a state-of-the-art rotating probe eddy current testing (ET) inspection system — a high-resolution non-destructive testing (NDT) methodology that enables precise localization of defects along the circumferential position of the tube. This advanced inspection capability distinguishes our coil tubes from standard offerings, ensuring that every length delivered meets the highest standards of quality and reliability.
The rotating probe configuration provides exceptional sensitivity for evaluating weld quality and detecting minute anomalies in small-bore tubing, making it an ideal solution for applications where even microscopic defects can compromise system performance or safety.
Material & Properties
- Material Grades: 304, 304L, 316, 316L, 321, 321H, 310S, 904L, and custom duplex stainless steel compositions
- Corrosion Resistance: Superior resistance to pitting, crevice, and intergranular corrosion across a wide range of chemical environments
- Mechanical Properties: High tensile strength with excellent ductility, suitable for cold forming and precision bending without cracking
- Surface Finish: Available in No. 4, 2B, BA (Bright Annealed), and mirror-polished finishes
- Operating Temperature Range: From cryogenic temperatures up to 870°C (depending on grade)
- Food-Grade Compliance: Fully compliant with FDA, NSF, and EU 1935/2004 food contact regulations
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | 3.0 mm – 108.0 mm |
| Wall Thickness | 0.3 mm – 6.0 mm |
| Coil Length | Up to 3,000 m per coil (standard); custom lengths available |
| OD Tolerance | ±0.05 mm (precision grade); ±0.10 mm (standard grade) |
| Wall Thickness Tolerance | ±0.02 mm (precision grade); ±0.05 mm (standard grade) |
| Roundness | ≤ 0.03 mm |
| Coil Inner Diameter | 250 mm – 500 mm (configurable) |
| Surface Roughness (Ra) | ≤ 0.4 μm (electropolished); ≤ 0.8 μm (standard) |
| Defect Detection Sensitivity | ≥ 5% AT (Area × Thickness) via rotating probe ET |
| Circumferential Defect Localization | ±2° angular accuracy |
Manufacturing Process
- Raw Material Selection: Only certified, mill-tested stainless steel strip from approved suppliers is used, with full traceability from heat number to finished coil.
- Forming & Welding: Precision roll-forming machines shape the strip into seamless or welded coil tubes. Where welded construction is required, high-frequency induction welding (HFW) or orbital TIG welding ensures consistent, uniform weld seams.
- Precision Sizing: Multi-stand cold sizing reduces OD and wall thickness to exact specifications while maintaining dimensional consistency across the entire coil length.
- Heat Treatment: Solution annealing in a protective atmosphere eliminates residual stresses and restores full corrosion resistance, particularly critical for 304L and 316L grades.
- Surface Finishing: Electropolishing or mechanical polishing is applied as required to achieve specified surface finish and remove any surface contaminants.
- Rotating Probe Eddy Current Inspection (NDT): Each coil undergoes 100% inline inspection using our proprietary rotating probe ET system. The rotating probe configuration provides high-resolution scanning capability with the unique ability to determine the exact circumferential position of any detected defect. This is particularly advantageous for:
- Weld Seam Evaluation: Precise assessment of weld integrity, including detection of undercut, porosity, incomplete fusion, and cracks along the full weld length.
- Small-Bore Tube Inspection: The compact rotating probe design is optimized for tubes with OD as small as 3.0 mm, where conventional straight probes may lack adequate sensitivity or resolution.
- Defect Characterization: High-resolution signal processing enables differentiation between surface and subsurface defects, providing actionable data for quality disposition.
Applications
- Heat Exchangers & Boilers: Coil tubes for shell-and-tube heat exchangers, condensers, and evaporators in chemical, petrochemical, and power generation plants.
- Food & Beverage Processing: Sanitary-grade tubing for dairy, brewing, pharmaceutical, and cosmetic processing equipment requiring CIP/SIP compatibility.
- Automotive Industry: Turbocharger exhaust manifolds, fuel injection lines, and EGR (Exhaust Gas Recirculation) systems.
- Medical Devices: Precision tubing for surgical instruments, endoscopes, and implant manufacturing.
- Petrochemical & Oil/Gas: High-pressure piping systems, downhole tools, and offshore platform instrumentation.
- Semiconductor & Electronics: Ultra-pure fluid delivery systems and vacuum chamber components.
- Aerospace: Hydraulic lines, fuel systems, and structural tubing requiring weight optimization with high strength-to-weight ratio.
Quality Certifications & Standards Compliance
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System
- ASME SA-213 / SA-269 — Boiler and Heat Exchanger Tube Standards
- ASTM A213 / A269 — Stainless Steel Tubing Specifications
- EN 10216-5 — European Stainless Steel Tube Standard
- JIS G3459 — Japanese Industrial Standard for Stainless Steel Tubes
- AMS 5600 Series — Aerospace Material Specifications
- ECRIN / PED 2014/68/EU — European Pressure Equipment Directive Compliance
- NDT Certification: Level II certified personnel per EN ISO 9712 / ASNT NDT Level II standards
- Mill Test Reports (MTR): Provided with every shipment, including chemical composition, mechanical properties, and full NDT inspection records
Unique Selling Points
- Industry-Leading NDT Technology: Our rotating probe eddy current inspection system offers unmatched circumferential defect localization capability — a critical advantage for weld seam evaluation and small-bore tube quality assurance.
- 100% Full-Length Inspection: Every meter of tubing is inspected, eliminating sampling bias and ensuring zero-defect delivery.
- Small-Bore Expertise: Specialized probe design and signal processing algorithms optimized for tubes as small as 3.0 mm OD, where traditional inspection methods fall short.
- Full Traceability: From raw material heat number through every processing step to final NDT results, complete traceability is maintained and documented.
- Customization Capability: Flexible manufacturing capacity allows for tailored specifications including custom dimensions, surface finishes, coil configurations, and specialized inspection protocols.
Wenzhou Jixing Metal Materials Co., Ltd. — Delivering precision-engineered stainless steel coil tubes backed by world-class non-destructive testing capabilities. Our rotating probe eddy current inspection system ensures that every defect, regardless of its circumferential position, is detected and documented — giving you absolute confidence in product integrity.