Stainless Steel Coil Tube (Coiltube) — Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is supplied in continuous coil form, enabling seamless integration into automated processing lines and downstream fabrication operations. The coil tube is specifically designed for applications requiring high thermal-hydraulic performance, including Fan Coil Unit (FCU) systems, heat exchangers, refrigeration circuits, and HVAC (Heating, Ventilation, and Air Conditioning) components.
As a supplier of precision stainless steel tubing, Wenzhou Jixing Metal Materials Co., Ltd. adheres to rigorous dimensional tolerances and material purity standards. The coil configuration offers logistical advantages in bulk transport and on-site processing efficiency, making it a preferred choice for OEM (Original Equipment Manufacturer) producers of thermal management systems.
2. Material & Properties
The Coil Tube is fabricated from high-grade austenitic stainless steel, with the following primary material grades available:
- AISI 304 / SUS 304 — General-purpose corrosion resistance with excellent formability (18% Cr, 8% Ni)
- AISI 316 / SUS 316 — Enhanced pitting and crevice corrosion resistance due to 2–3% Molybdenum addition
- AISI 321 / SUS 321 — Stabilized grade with Titanium addition for high-temperature applications
- AISI 316L / SUS 316L — Low-carbon variant for superior weldability and resistance to intergranular corrosion
Key Material Properties:
- Excellent resistance to oxidation and corrosion in a wide range of chemical environments
- Non-magnetic properties in the annealed condition
- High thermal conductivity suitable for heat transfer applications
- Outstanding hygienic surface finish, meeting food-grade and pharmaceutical standards
- Dimensional stability across operating temperatures from cryogenic to 870°C (1600°F)
- Full compliance with ASTM (American Society for Testing and Materials) and EN (European Norms) standards
3. Technical Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 3.0 mm – 50.8 mm (customizable) | ASTM A554 / EN 10216-5 |
| Wall Thickness | 0.3 mm – 3.0 mm (customizable) | ASTM A554 / EN 10216-5 |
| OD Tolerance | ±0.05 mm – ±0.10 mm | ASTM A554 |
| Wall Thickness Tolerance | ±10% or ±0.02 mm (whichever is greater) | EN 10216-5 |
| Coil Length | 5 m – 150 m (configurable per order) | — |
| Surface Finish | Pickled & Annealed (2B), Bright Annealed (BA), or Custom Ra ≤ 0.4 μm | ASTM A473 |
| End Condition | Plain cut, Beveled, or Crimped | — |
| Delivery Form | Continuous Coil on Steel Spool | — |
| Heat Treatment | Solution Annealed at 1010°C – 1150°C with rapid cooling | ASTM A473 |
| Maximum Operating Temperature | 870°C (1600°F) continuous | ASM (American Society for Metals) |
| Minimum Operating Temperature | −196°C (−320°F) cryogenic | ASTM A312 |
| Yield Strength (Typical) | ≥ 205 MPa (304); ≥ 170 MPa (316L) | ASTM A580 |
| Tensile Strength (Typical) | 515 – 750 MPa | ASTM A580 |
| Elongation (Min.) | ≥ 30% | ASTM A580 |
4. Manufacturing Process
The production of the Stainless Steel Coil Tube follows a multi-stage, precision-controlled manufacturing sequence:
- Raw Material Selection: High-purity stainless steel strip (cold-rolled coil) sourced from certified mill producers, verified through Spectrometer analysis for chemical composition compliance.
- Slitting: The master coil is slit to the target width using precision slitting lines with edge-quality control to eliminate burrs and surface defects.
- Forming (Rolling): The flat strip is passed through a series of progressively reducing forming rolls to achieve the desired circular cross-section with uniform wall thickness. Multi-roll forming technology ensures roundness tolerance within ±0.05 mm.
- Welding: Longitudinal weld formation is achieved via High-Frequency Induction Welding (HF-W) or TIG (Tungsten Inert Gas) welding. The weld zone undergoes internal and external grinding to achieve a flush finish.
- Heat Treatment (Solution Annealing): Continuous annealing in a protective atmosphere furnace at temperatures between 1010°C and 1150°C, followed by controlled cooling. This eliminates residual stresses and restores full austenitic microstructure.
- Pickling & Passivation: Chemical pickling removes mill scale and oxide layers; subsequent passivation treatment forms a protective chromium oxide film on the surface.
- Quality Inspection: Each coil undergoes ultrasonic testing (UT), dimensional verification via laser micrometers, and visual inspection for surface integrity.
- Coiling & Packaging: The finished tube is wound onto steel spools with protective wrapping (VCI paper or plastic film) and secured for transport.
5. Applications
The Stainless Steel Coil Tube finds extensive use across multiple high-performance engineering sectors:
- Fan Coil Unit (FCU) Systems: Serves as the primary heat transfer element in mixed thermal-hydraulic FCU systems, where optimal coil geometry and material properties ensure efficient air-side and water-side heat exchange.
- HVAC Heat Exchangers: Used in condenser, evaporator, and plate-fin coil assemblies for commercial and industrial air conditioning.
- Refrigeration & Cryogenics: Suitable for ammonia, Freon, and CO₂ refrigerant circuits due to excellent low-temperature toughness.
- Automotive Industry: Applied in automotive air conditioning condensers and evaporators requiring lightweight, high-efficiency tubing.
- Food & Beverage Processing: Hygienic-grade tubing for pasteurization systems, CIP (Clean-in-Place) loops, and fluid transfer lines.
- Pharmaceutical & Medical Equipment: Used in sterilization systems, fluid delivery lines, and medical device components requiring biocompatibility.
- Energy & Power Generation: Employed in solar thermal collectors, geothermal heat exchangers, and nuclear-grade heat transfer circuits.
- Chemical Processing: Resistant to aggressive chemical media including acids, alkalis, and chlorinated environments (particularly 316/316L grades).
6. Unique Selling Points
The Wenzhou Jixing Metal Materials Co., Ltd. Coil Tube product line distinguishes itself through:
- Precision Dimensional Control: Advanced multi-roll forming and laser inspection systems ensure tight tolerances critical for automated downstream processing.
- Thermal-Hydraulic Optimization: Uniform wall thickness and consistent roundness contribute to predictable flow characteristics and enhanced heat transfer coefficients in FCU and heat exchanger applications.
- Full Traceability: Each coil is accompanied by a Mill Test Certificate (MTC) with heat number, chemical composition, and mechanical property data for complete supply chain traceability.
- Customization Capability: Flexible OD, wall thickness, coil length, and surface finish options accommodate diverse OEM requirements.
- Corrosion Durability: Superior resistance to pitting, stress corrosion cracking (SCC), and intergranular corrosion extends service life in aggressive environments.
7. Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains the following quality management and product certifications:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- CE Marking — European Conformity for pressure equipment and components
- EN 10204 3.1 Certificate — Third-party material inspection certificate
- ASTM Compliance — Products conform to ASTM A554, A580, A473, A312, and A473 specifications
- GB/T Standards Compliance — Chinese National Standards for stainless steel tubing (GB/T 14975, GB/T 12771)
- NSF/ANSI 61 — Drinking water system component certification (available upon request)
All products are subject to incoming material inspection (IQC), in-process quality control (IPQC), and final quality assurance (FQA) before dispatch, ensuring consistent quality from raw material to finished coil delivery.