Stainless Steel Coil Tube (Coiltube) – Wenzhou Jixing Metal Materials Co., Ltd.
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a high-performance tubular product supplied in continuous coil form, engineered for seamless integration into HVAC (Heating, Ventilation, and Air Conditioning) systems, industrial heat exchangers, dry coil systems, and precision fluid transport applications. The coil configuration enables efficient downstream processing—such as coil forming, bending, and cut-to-length operations—without the introduction of weld seams, thereby preserving material integrity and maximizing hydraulic efficiency.
This product is particularly valued in dry coil system architectures, where the coil tube serves as the primary heat transfer medium for sensible cooling and dehumidification processes. The continuous coil geometry facilitates compact, high-surface-area heat exchanger designs that are critical in modern energy-efficient building systems and process engineering.
Material & Properties
The coil tube is fabricated from austenitic stainless steel grades conforming to international standards, ensuring superior corrosion resistance, mechanical strength, and thermal conductivity across a broad range of operating conditions.
- Primary Grades: AISI 304 (UNS S30400), AISI 316 (UNS S31600), AISI 321 (UNS S32100)
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, chemical media, and high-temperature oxidation; particularly suitable for chlorinated environments when 316 grade is selected
- Thermal Conductivity: 14.9–16.3 W/(m·K) at 20°C (AISI 304), providing reliable heat transfer performance
- Operating Temperature Range: −196°C to +870°C (AISI 304); −196°C to +815°C (AISI 316)
- Surface Finish Options: 2B (mill finish), No. 4 (brushed), BA (Bright Annealed), EP (Electro-Polished)
- Hygienic Compliance: Available in sanitary-grade finishes meeting FDA and 3-A (Three-A Sanitary Standards) requirements
Specifications
| Parameter | Specification / Range |
|---|---|
| Outer Diameter (OD) | Φ3.0 mm – Φ50.8 mm (custom diameters available upon request) |
| Wall Thickness | 0.3 mm – 3.0 mm |
| Coil Length | Typically 50 m – 500 m per coil (custom lengths available) |
| Coil Inner Diameter (ID) | Φ300 mm – Φ1200 mm (configurable to customer requirements) |
| Dimensional Tolerance | OD: ±0.05 mm; Wall Thickness: ±0.02 mm (precision grades) |
| Strain Hardening | Available in annealed (soft), semi-hard, and hard-tempered conditions |
| End Condition | Plain ends, beveled ends, or threaded ends per customer specification |
| Standards Referenced | ASTM A213/A213M, ASTM A269/A269M, EN 10217-7, GB/T 12771, JIS G3459 |
| Packaging | Wooden pallet with moisture-proof wrapping; protective end caps; coil cradles for transport |
Manufacturing Process
The production of stainless steel coil tube at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous multi-stage manufacturing sequence designed to ensure dimensional accuracy, metallurgical uniformity, and surface quality:
- Raw Material Selection: High-purity stainless steel strip or seamless tube blanks are sourced from certified mills, with incoming material subjected to spectroscopic analysis for chemical composition verification.
- Coil Winding / Tube Drawing: Continuous coil tube is produced via cold-drawing through precision-die systems, achieving tight dimensional tolerances and superior surface finish without introducing thermal distortion.
- Heat Treatment (Annealing): Tubes are annealed in a controlled atmosphere furnace to relieve residual stresses from cold working, restore full soft temper, and eliminate carbide precipitation in stabilized grades.
- Pickle & Passivate: Surface contaminants and scale are removed through acid pickling, followed by passivation treatment to form a protective chromium oxide layer, enhancing long-term corrosion resistance.
- Precision Surface Finishing: Electropolishing or mechanical polishing is applied where hygienic or optical surface quality is required, achieving Ra values as low as 0.1 μm.
- Quality Inspection: Each coil undergoes hydrostatic pressure testing, dimensional measurement (laser-based OD and wall thickness scanning), visual inspection, and, where applicable, eddy current testing for internal defect detection.
- Coil Spooling & Packaging: Finished coils are spooled onto protective cradles, wrapped in moisture-barrier film, and secured for international shipping compliance.
Applications
The stainless steel coil tube is engineered for a wide spectrum of demanding industrial and commercial applications:
- DRY COIL SYSTEMS (Sensible Cooling): Primary heat transfer tubes in dry coil air handling units (AHUs), where the coil tube facilitates sensible heat exchange for dehumidification-free cooling in data centers, hospitals, and precision manufacturing facilities. The coil tube geometry enables compact serpentine or plate-and-fin heat exchanger configurations that integrate with fresh air unit selection for optimal thermal performance.
- HVAC Heat Exchangers: Evaporator and condenser tubes in commercial and industrial refrigeration systems, air source heat pumps, and chiller units.
- Food & Beverage Processing: Hygienic-grade coil tubes in pasteurizers, condensers, and CIP (Clean-In-Place) systems where sanitary surface requirements are paramount.
- Pharmaceutical & Biotechnology: GMP (Good Manufacturing Practice) compliant tubing in bioreactors, fermentation vessels, and pharmaceutical fluid transfer lines.
- Chemical Processing: Corrosion-resistant coil tubes in acid handling, solvent recovery, and chemical heat exchanger applications, particularly utilizing AISI 316 grade for chlorinated media.
- Automotive & Aerospace: Lightweight coil tubes in fuel lines, brake systems, and hydraulic circuits requiring high strength-to-weight ratios and vibration resistance.
- Solar Thermal Systems: Absorber tubes in evacuated tube solar collectors and solar water heating systems.
- Oil & Gas: Downhole tubing and surface flow lines in corrosive well environments.
Unique Selling Points
- Continuous Coil Configuration: Eliminates field welding, reducing leak points and maintenance requirements while enabling automated, high-speed downstream forming operations.
- Precision Dimensional Control: Laser-monitored production ensures ±0.05 mm OD tolerance, critical for press-fit heat exchanger tube sheet assembly.
- Multi-Grade Flexibility: Availability in 304, 316, and 321 grades allows engineers to optimize material selection for specific corrosion and temperature environments.
- Hygienic Surface Options: Electropolished finish with Ra ≤ 0.1 μm meets the most stringent sanitary and pharmaceutical requirements.
- Full Traceability: Each coil is accompanied by a mill test certificate (MTC) with heat number, chemical analysis, and mechanical test results, ensuring complete supply chain traceability.
- Custom Engineering Support: Wenzhou Jixing provides OEM/ODM customization for coil diameter, wall thickness, length, and surface treatment to match specific project requirements.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework validated by internationally recognized certifications:
- ISO 9001:2015 – Quality Management System certification, demonstrating adherence to internationally accepted quality standards for consistent product excellence.
- ISO 14001:2015 – Environmental Management System certification, confirming responsible environmental practices throughout the manufacturing lifecycle.
- ISO 45001:2018 – Occupational Health and Safety Management System certification, ensuring workplace safety and regulatory compliance.
- CE Marking – Conformity with European Union directives for products marketed in the European Economic Area (EEA).
- SGS Testing – Third-party verification of material composition, mechanical properties, and dimensional accuracy by SGS (Société Générale de Surveillance).
- ASTM & EN Compliance: Products manufactured and tested in accordance with ASTM A213, ASTM A269, EN 10217-7, and applicable national standards.
- Mill Test Certificate (MTC): Every shipment is accompanied by a comprehensive MTC including heat number, chemical composition analysis, mechanical test data (tensile strength, yield strength, elongation), and hydrostatic test results.
Note: The coil tube product line is designed with particular attention to its integration in dry coil system architectures, where proper coil tube specification and fresh air unit (FAU) selection are interdependent factors in achieving optimal sensible cooling capacity, energy efficiency, and system longevity. Wenzhou Jixing Metal Materials Co., Ltd. offers technical consultation support for system-level design optimization.