Stainless Steel Coil Tube (Coiltube) — Model JX-CT Series
Product Overview
The Stainless Steel Coil Tube (Coiltube), manufactured by Wenzhou Jixing Metal Materials Co., Ltd, is a precision-engineered tubular product formed into continuous coil configurations. Designed for high-performance thermal exchange and fluid conveying applications, this product line leverages the superior corrosion resistance, mechanical integrity, and thermal conductivity inherent to austenitic and ferritic stainless steel grades. The coil tube is particularly valued in HVAC (Heating, Ventilation, and Air Conditioning) systems, where it serves as the core heat transfer element in fan coil units and air handling assemblies. Its seamless coil geometry ensures uniform fluid distribution, minimal pressure drop, and extended operational life under demanding environmental conditions.
This product has been extensively studied and validated in academic and engineering contexts, including research on microcontroller-based temperature control systems (e.g., designs utilizing the STC51W408AS microcontroller for centralized air conditioning fan coil unit regulation), which underscore the critical role of coil tube performance characteristics in thermal management efficiency.
Material & Properties
The JX-CT Series coil tubes are fabricated from high-purity stainless steel alloys, selected for their exceptional balance of strength, ductility, and resistance to chemical attack. The following material grades are available:
- 304 / 1.4301 (AISI 304): General-purpose austenitic stainless steel offering excellent corrosion resistance in non-reducing environments. Contains 18% Chromium (Cr) and 8% Nickel (Ni).
- 316 / 1.4401 (AISI 316): Enhanced austenitic grade with 2–3% Molybdenum (Mo) for superior resistance to pitting and crevice corrosion, suitable for marine and chemical processing applications.
- 321 / 1.4541 (AISI 321): Titanium-stabilized austenitic grade providing excellent resistance to intergranular corrosion at elevated temperatures (up to 870°C).
- 430 / 1.4016 (AISI 430): Ferritic stainless steel with good oxidation resistance at moderate temperatures, offering a cost-effective alternative for less aggressive environments.
Key Material Properties:
- Corrosion resistance to atmospheric, aqueous, and food-grade environments
- High-temperature oxidation resistance (up to 800–870°C depending on grade)
- Non-magnetic (austenitic grades) or weakly magnetic (ferritic grades)
- Hygienic, non-toxic surface finish suitable for pharmaceutical and food processing
- Weldable and formable without loss of structural integrity
Specifications
| Parameter | Specification / Range | Standard / Reference |
|---|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) | — |
| Model Series | JX-CT Series | Wenzhou Jixing Metal Materials Co., Ltd |
| Material Grade | 304, 316, 321, 430, and custom alloys | ASTM A213 / A269; EN 10216-5 |
| Outer Diameter (OD) | 6 mm – 219 mm (customizable) | ISO 3505 / ASTM A511 |
| Wall Thickness | 0.3 mm – 6.0 mm (customizable) | ASTM A213 / EN 10216-5 |
| Coil Inner Diameter (ID) | 200 mm – 2,000 mm (adjustable per order) | Manufacturer specification |
| Coil Length | 50 m – 2,000 m per coil (continuous) | Customer requirement |
| Surface Finish | 2B, BA (Bright Annealed), No.4, No.8 (Mirror), HL (Hairline) | ASTM A480 |
| Tolerance on OD | ±0.05 mm – ±0.5 mm (depending on diameter) | ISO 8494 / GB/T 14976 |
| Tolerance on Wall Thickness | ±0.02 mm – ±0.3 mm | ISO 8494 / GB/T 14976 |
| Operating Temperature Range | −196°C to +870°C (grade-dependent) | ASME BPVC Section II |
| Maximum Working Pressure | Up to 6.3 MPa (design-dependent) | ASME B31.3 / EN 13480 |
| End Treatment | Plain end, beveled, or custom per customer specification | ISO 15494 |
| Coil Packaging | Wooden pallet with moisture-proof wrapping; export-grade packaging available | ISO 4180 |
Manufacturing Process
The JX-CT Series coil tubes are produced through a rigorously controlled multi-stage manufacturing process to ensure dimensional accuracy, metallurgical homogeneity, and surface quality:
- Raw Material Procurement: High-purity stainless steel strip or tube blanks are sourced from certified suppliers and subjected to incoming inspection, including spectroscopic composition analysis (Optical Emission Spectroscopy, OES) and mechanical property verification.
- Forming / Coiling: Precision tube blanks are wound into continuous coil configurations using CNC-controlled coiling machinery. The coil diameter and pitch are programmatically adjusted to meet customer specifications, ensuring uniform curvature without plastic deformation or wall thinning.
- Welding (if applicable): For welded coil tube configurations, TIG (Tungsten Inert Gas) welding or laser welding is employed with a protective inert gas atmosphere (Argon or Helium) to prevent oxidation. Weld seams are ground and inspected for continuity.
- Heat Treatment / Annealing: Solution annealing is performed in a controlled atmosphere furnace to relieve residual stresses, restore full austenitic microstructure, and enhance corrosion resistance. Annealing temperatures are maintained between 1010°C and 1150°C followed by rapid water quenching.
- Pickling and Passivation: The coil tube surface is cleaned via acid pickling (nitric/hydrofluoric acid blend) to remove oxide scale, followed by passivation to restore the protective chromium oxide layer (Cr₂O₃) essential for corrosion resistance.
- Surface Finishing: Depending on the specified finish (2B, BA, No.4, No.8, or HL), mechanical polishing, electrolytic polishing, or mechanical buffing is applied to achieve the required surface roughness (Ra ≤ 0.8 μm for BA finish).
- Quality Inspection: Each coil undergoes comprehensive inspection including dimensional measurement (OD, wall thickness, coil diameter), visual surface examination, hydrostatic pressure testing, and optional NDT (Non-Destructive Testing) methods such as Eddy Current Testing (ECT) or Radiographic Testing (RT).
- Packaging and Shipping: Finished coils are wrapped in moisture-proof protective film, placed on wooden pallets, and secured with steel strapping. Export packaging complies with ISPM-15 (International Standards for Phytosanitary Measures) requirements for wooden materials.
Applications
The JX-CT Series stainless steel coil tubes find extensive application across multiple industrial sectors:
- HVAC Systems: Primary application as heat exchange coils in fan coil units, air handling units (AHUs), and chiller systems. The coil tube geometry facilitates efficient heat transfer between refrigerant and air streams, a critical component studied in microcontroller-based temperature control system designs (e.g., STC51W408AS-based controllers for centralized air conditioning).
- Food and Beverage Processing: Hygienic coil tubes used in pasteurization systems, CIP (Clean-in-Place) loops, and sanitary piping networks where non-toxic, corrosion-resistant materials are mandated by FDA and EU regulations.
- Pharmaceutical Manufacturing: GMP-compliant coil tubes for process piping, heat exchangers, and steam distribution systems requiring the highest levels of surface cleanliness and corrosion resistance.
- Chemical Processing: 316 and 316L grade coil tubes deployed in aggressive chemical environments, acid storage systems, and reactor heat exchange loops.
- Marine and Offshore: Resistant to saltwater corrosion, suitable for desalination plants, ballast water systems, and offshore platform piping.
- Energy Sector: Coil tubes in solar thermal collectors, geothermal heat exchange systems, and power plant auxiliary circuits.
- Automotive and Aerospace: Precision coil tubes for fuel lines, hydraulic systems, and thermal management components requiring lightweight, high-strength materials.
- Medical Devices: Biocompatible coil tubes for endoscopic instruments, dialysis equipment, and implantable device components.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system and holds the following certifications and complies with the following international standards:
- ISO 9001:2015 — Quality Management System certification, ensuring consistent product quality and process control across all manufacturing operations.
- ISO 14001:2015 — Environmental Management System certification, demonstrating commitment to sustainable manufacturing practices and environmental stewardship.
- ISO 45001:2018 — Occupational Health and Safety Management System certification, ensuring safe working conditions and regulatory compliance.
- CE Marking — Conformity with European Union directives for product safety and market access.
- ASME Certification — Compliance with American Society of Mechanical Engineers standards for pressure vessels and piping systems.
- EN 10204 3.1 / 3.2 — Third-party inspection and material certification per European standard, available upon request.
- Mill Test Reports (MTR) — Comprehensive chemical composition, mechanical property, and dimensional test data provided with every shipment.
- NSF/ANSI 61 — Compliance for water system components in contact with potable water (where applicable).
- 3-A Sanitary Standards — Compliance with sanitary design requirements for dairy, food, and beverage processing equipment.
- RoHS & REACH Compliance — Restriction of Hazardous Substances and Registration, Evaluation, Authorisation and Restriction of Chemicals compliance for global market access.
Unique Selling Points
- Precision Coiling Technology: CNC-controlled coiling ensures dimensional consistency and eliminates manual errors, delivering uniform coil geometry critical for downstream forming and installation.
- Customization Capability: Full customization of OD, wall thickness, coil diameter, length, surface finish, and end treatment to meet exact customer specifications and project requirements.
- Proven HVAC Application Performance: Extensively validated in centralized air conditioning and fan coil unit applications, with documented integration into microcontroller-based temperature control systems for optimized thermal regulation.
- End-to-End Quality Assurance: From raw material verification through final inspection, a traceable quality chain ensures every coil tube meets the highest international standards.
- Wide Material Grade Availability: Multiple stainless steel grades (304, 316, 321, 430, and custom alloys) provide flexibility for diverse application environments and regulatory requirements.
- Export-Ready Packaging: ISPM-15 compliant, moisture-protected packaging ensures product integrity during international shipping and storage.
Technical Notes
The integration of stainless steel coil tubes into HVAC fan coil units represents a critical interface between passive heat transfer components and active control systems. Research documented in academic literature — including designs based on the STC51W408AS single-chip microcontroller for centralized air conditioning fan coil temperature controllers — highlights the importance of coil tube thermal response characteristics, flow uniformity, and pressure-drop behavior in achieving precise temperature regulation. The JX-CT Series coil tubes are engineered to provide the dimensional accuracy and material consistency required for optimal sensor placement, uniform heat exchange, and reliable long-term operation within automated control loops.
Contact & Ordering
For detailed quotations, technical datasheets, sample requests, or custom specification discussions, please contact Wenzhou Jixing Metal Materials Co., Ltd directly. The engineering team is available to provide application-specific guidance, material selection recommendations, and compliance documentation tailored to project requirements.