Stainless Steel Coil Tube (Coiltube) — Wenzhou Jixing Metal Materials Co., Ltd
Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered tubing product supplied in continuous coil form, designed for high-purity, corrosion-resistant applications in industrial HVAC, cleanroom systems, and process engineering. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd, this product is specifically optimized for integration into dry coil (dry pipe) systems and fresh air pre-treatment units operating within clean workshop environments. The coil tube delivers superior thermal conductivity, mechanical integrity, and long-term chemical stability, making it an ideal material for air-handling components where contamination control and hygienic performance are paramount.
Material & Properties
The coil tube is fabricated from austenitic stainless steel grades, most commonly SUS304 (UNS S30400) and SUS316L (UNS S31603), selected for their exceptional resistance to oxidation, pitting, and crevice corrosion. Key material properties include:
- Corrosion Resistance: Superior resistance to atmospheric, chemical, and microbial degradation; particularly suited for cleanroom-grade air handling where particulate and microbial contamination must be minimized.
- Thermal Conductivity: Austenitic stainless steel provides adequate heat transfer performance for dry coil applications, enabling efficient sensible heat exchange without moisture condensation on the coil surface.
- Mechanical Strength: High yield strength and tensile strength ensure dimensional stability under thermal cycling and internal pressure loads typical in HVAC and process piping systems.
- Hygienic Surface Finish: Available in electropolished (Ra ≤ 0.5 μm) or passivated surface finishes, facilitating easy cleaning and preventing biofilm formation — critical for pharmaceutical, biotechnology, and semiconductor cleanroom environments.
- Non-magnetic (Austenitic): Suitable for environments where magnetic interference must be avoided.
- Weldability: Excellent formability and weldability permit seamless integration into custom system assemblies.
Specifications
| Parameter | Specification / Range |
|---|---|
| Material Grade | SUS304 (UNS S30400), SUS316L (UNS S31603), or custom austenitic grades |
| Outer Diameter (OD) | 6.0 mm – 50.8 mm (¼" – 2") |
| Wall Thickness (WT) | 0.5 mm – 3.0 mm |
| Coil Width | Standard coil widths up to 1200 mm; custom widths available |
| Coil Length | Continuous coil, typically 50 m – 500 m per coil |
| Surface Finish | No. 1, 2B, BA (Bright Annealed), Electropolished (Ra ≤ 0.5 μm), Passivated |
| Manufacturing Standard | ASTM A213 / A269, EN 10216-5, GB/T 12771 |
| Temperature Range | −196 °C to +870 °C (SUS304); −196 °C to +870 °C (SUS316L) |
| Maximum Operating Pressure | Up to 2.0 MPa (dependent on OD and WT) |
| Acid Number (AN) / Nickel Content | Cr: 18.0–20.0% (304) / 16.5–18.5% (316L); Ni: 8.0–10.5% (304) / 10.0–14.0% (316L) |
| Packaging | Wooden pallet with moisture-proof wrapping; coil core with protective end caps |
Manufacturing Process
The production of the stainless steel coil tube follows a rigorous multi-stage process to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Material Selection & Incoming Inspection: Raw stainless steel strip is sourced from certified mills. Chemical composition is verified via Optical Emission Spectroscopy (OES) and Positive Material Identification (PMI) to confirm grade compliance.
- Slitting & Coiling: Wide-strip stainless steel is precision-slitted to the required coil tube dimensions using servo-controlled slitting lines, ensuring tight dimensional tolerances (±0.05 mm).
- Forming & Seaming: The slit strip is formed into a tubular geometry through roll-forming or UO (U-shaped bending + Overlap) processes, followed by high-frequency resistance welding or orbital TIG welding to create a continuous, leak-tight seam.
- Heat Treatment & Annealing: Tubes undergo controlled solution annealing at 1050 °C – 1150 °C followed by rapid quenching to restore full austenitic structure, eliminate residual stresses, and maximize corrosion resistance.
- Surface Finishing: Depending on application requirements, tubes are subjected to pickling and passivation (to remove scale and form a protective chromium oxide layer), or electropolishing for ultra-low surface roughness (Ra ≤ 0.5 μm).
- Quality Control & Testing: Each batch undergoes hydrostatic pressure testing, dimensional inspection (laser gauge), surface roughness measurement, and visual inspection. Radiographic testing (RT) may be performed on weld seams for critical applications.
- Packaging & Dispatch: Finished coils are wound onto protective cores, wrapped in moisture-barrier film, and secured on wooden pallets for safe transit.
Applications
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd is engineered for demanding applications where material purity, corrosion resistance, and hygienic performance are non-negotiable:
- Dry Coil (Dry Pipe) Systems in Clean Workshops: The primary application domain. In cleanroom HVAC systems, the coil tube serves as the heat exchange medium in dry coil units that dehumidify air without surface condensation. This prevents microbial growth and particulate generation on wet surfaces, maintaining ISO 14644 cleanroom classification integrity.
- Fresh Air Pre-treatment Systems: Used in pre-filter and pre-conditioning modules that condition incoming outdoor air before it enters the cleanroom environment, ensuring temperature and humidity stability at the source.
- Pharmaceutical & Biotechnology Processing: Suitable for piping and heat exchange in GMP (Good Manufacturing Practice) compliant facilities where product purity and process integrity are regulated.
- Food & Beverage Industry: Hygienic-grade coil tubes used in pasteurization, sterilization, and sanitary piping systems.
- Semiconductor Manufacturing: Ultra-clean process piping for ultra-pure water (UPW), chemical delivery, and vacuum systems in wafer fabrication facilities.
- Chemical & Petrochemical Processing: Corrosion-resistant coil tubing for aggressive chemical environments, acid handling, and high-purity process streams.
- Medical Equipment: Components for medical gas delivery, sterilization equipment, and diagnostic instrument housings.
- Heat Exchanger Manufacturing: Coil tubes are used as raw material for fabricating shell-and-tube heat exchangers, air-to-air heat exchangers, and evaporator/condenser coils.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework to ensure consistent product performance and regulatory compliance:
- ISO 9001:2015 — Quality Management Systems certification, demonstrating systematic commitment to customer satisfaction and continuous improvement.
- ISO 14001:2015 — Environmental Management Systems certification, reflecting responsible manufacturing practices and environmental stewardship.
- ISO 45001:2018 — Occupational Health and Safety Management Systems certification.
- CE Marking — Conformity with European Union health, safety, and environmental protection standards.
- EN 10204 3.1 — Third-party material certification for each production batch, providing independent verification of chemical composition, mechanical properties, and dimensional accuracy.
- Mill Test Reports (MTR) — Comprehensive documentation including chemical analysis, mechanical test results, heat treatment records, and non-destructive testing reports supplied with every shipment.
- ASTM / GB Standards Compliance — Products manufactured and tested in accordance with ASTM A213, ASTM A269, and GB/T 12771 standards.
Unique Selling Points
1. Cleanroom-Grade Hygiene: Electropolished surface finish with Ra ≤ 0.5 μm ensures minimal particulate shedding and eliminates harborage points for microbial contamination — a critical advantage in dry coil and fresh air pre-treatment applications within clean workshops.
2. Seamless Integration with Dry Coil Systems: The coil tube geometry is specifically optimized for dry coil heat exchanger fabrication, enabling efficient sensible heat exchange while preventing condensation — the root cause of microbial growth in conventional wet coils.
3. Dual-Grade Availability: Both SUS304 and SUS316L grades are available, providing customers with flexibility to select the optimal balance of cost and corrosion resistance for their specific application environment.
4. Continuous Coil Format: The coil supply format enables high-speed automated cutting and forming, reducing manufacturing waste and lead times for downstream fabricators of HVAC components and process piping.
5. Full Traceability: Every coil is serialized and accompanied by a complete MTR package, ensuring full material traceability from mill origin to final installation — essential for regulated industries.
6. Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd offers custom OD, wall thickness, surface finish, and coil dimensions to meet project-specific engineering requirements.