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

Product Overview

The Stainless Steel Coil Tube (also referred to as Coiltube or Coil Pipe) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered continuous length tubing product formed into a helical or serpentine coil configuration. This product category encompasses a wide range of stainless steel coil tubes designed for industrial heat exchange, refrigeration, HVAC (Heating, Ventilation, and Air Conditioning), and fluid conveying applications. The coil tube is produced from high-grade austenitic and duplex stainless steel grades, offering superior corrosion resistance, mechanical strength, and thermal performance in demanding environments.

Wenzhou Jixing Metal Materials Co., Ltd leverages advanced metallurgical expertise and precision forming technology to deliver coil tubes that meet international standards for dimensional accuracy, surface finish, and metallurgical integrity. The product line addresses critical industry challenges, including the failure mechanisms observed in temperature sensing wire coils within air conditioning coil assemblies, where material fatigue, thermal cycling, and corrosion can compromise system reliability.

Material & Properties

The stainless steel coil tubes are manufactured from premium alloy grades selected based on application-specific requirements:

Key Material Properties:

Specifications

Parameter Specification / Range Standard Reference
Outer Diameter (OD) Φ 1.0 mm – Φ 50.8 mm (0.040" – 2.000") ASTM A269 / ASTM A213
Wall Thickness 0.10 mm – 3.00 mm (0.004" – 0.118") ASTM A269 / EN 10216-5
Coil Diameter Φ 300 mm – Φ 3000 mm (configurable) Customer-specific
Tube Length (Continuous) Up to 50,000 m per coil (continuous production) —
Dimensional Tolerance (OD) ±0.05 mm to ±0.20 mm ASTM A269 / GB/T 12771
Dimensional Tolerance (Wall) ±10% of nominal ASTM A269
End Condition Plain end, beveled end, or thread-formable Customer-specific
Surface Roughness (Ra) 0.2 μm – 1.6 μm (electropolished / polished) ISO 1302
Heat Treatment Solution annealed (1050–1150 °C), stress-relieved ASTM A269
Available Grades 304, 304L, 316, 316L, 321, 310S, 31803, 32205, 904L ASTM / EN / JIS / GB
Testing Hydrostatic, eddy current, dimensional, PMI (Positive Material Identification) ASTM A269 / EN 10216-5
Packaging Coiled on wooden reel, VCI (Vapor Corrosion Inhibitor) wrapped, export-grade —

Manufacturing Process

The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous, multi-stage manufacturing workflow designed to ensure consistent quality and dimensional precision:

  1. Raw Material Selection & Inspection: Hot-rolled coil (HRC) or continuous casting slab from certified mills, subjected to incoming material inspection including chemical composition analysis (via OES/Spectroscopy), PMI verification, and mechanical property testing.
  2. Pipe Forming (Seamless or Welded): Seamless tubes are produced via automatic piercing and rolling (e.g., Mannesmann or capillary method); welded tubes are produced via ERW (Electric Resistance Welding) or TIG (Tungsten Inert Gas) welding with precise weld seam control.
  3. Precision Sizing & Cold Drawing: Tubes pass through multi-stage cold drawing and sizing operations to achieve exact OD and wall thickness tolerances while maintaining metallurgical integrity.
  4. Solution Annealing: Tubes are solution-annealed at 1050–1150 °C followed by controlled water quenching to dissolve carbides, restore ductility, and maximize corrosion resistance (particularly critical for preventing sensitization in 304L/316L grades).
  5. Pickling & Passivation: Chemical pickling removes oxide scale; passivation treatment forms a stable chromium oxide layer (Cr₂O₃) for enhanced corrosion protection. Passivation solutions conform to ASTM A967.
  6. Surface Finishing: Options include mechanical polishing, electrolytic polishing (EP), or bright annealing (BA) to achieve specified surface roughness and aesthetic quality.
  7. Coil Winding & Forming: The continuous tube is wound into coil configuration using precision-controlled winding machines with tension regulation to prevent kinking or deformation. Custom coil diameters and pitch configurations are available.
  8. Non-Destructive Testing (NDT): 100% inline eddy current testing (ECT) for seam integrity and wall defects; hydrostatic pressure testing (typically 2–3× working pressure) for leak-tightness verification.
  9. Final Inspection & Packaging: Dimensional verification, surface quality audit, documentation preparation, and export-grade packaging with protective wrapping and securing on wooden or steel reels.

Applications

Stainless steel coil tubes from Wenzhou Jixing Metal Materials Co., Ltd serve a broad spectrum of industrial applications:

Quality Certifications & Standards Compliance

Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system and holds the following certifications and standards compliance:

Unique Selling Points

Technical Notes on Thermal Cycling & Fatigue Performance

Research into the failure mechanisms of temperature sensing line coils in air conditioning coil assemblies has identified thermal fatigue cracking, intergranular corrosion sensitization, and stress corrosion cracking (SCC) as primary degradation pathways. Wenzhou Jixing's coil tube products address these concerns through:

  • Low-carbon grades (304L, 316L with C ≤ 0.03%) to prevent sensitization during thermal cycling.
  • Controlled cold work levels to balance yield strength with fatigue crack growth resistance.
  • Post-manufacture stress relief annealing to eliminate residual stresses from forming operations.
  • Optional stabilizing treatment (Ti/Nb addition in 321/347 grades) for sustained high-temperature service.

Wenzhou Jixing Metal Materials Co., Ltd — Delivering precision-engineered stainless steel coil tube solutions for global industrial applications with uncompromising quality, metallurgical integrity, and technical expertise.