Stainless Steel Coil Tube — High-Efficiency Continuous Coiling Product
Product Overview
The Stainless Steel Coil Tube is a continuously formed tubular product manufactured through a high-speed coiling process, enabling production cycle times as short as 20 seconds per unit for downstream coil-based assemblies (e.g., fan coil units). This exceptional throughput capability positions the product as a cornerstone component in modern HVAC (Heating, Ventilation, and Air Conditioning), heat exchanger, and fluid transport systems. The coil tube is supplied in continuous lengths, wound onto spools, allowing seamless feeding into automated forming, cutting, and bending lines, thereby minimizing material waste and maximizing manufacturing efficiency.
Material & Properties
Wenzhou Jixing Metal Materials Co., Ltd. offers stainless steel coil tubes in a range of standard and specialty grades, each selected to meet the mechanical, chemical, and thermal demands of specific end-use applications.
- Austenitic Grades: 304 (UNS S30400), 304L (UNS S30403), 316 (UNS S31600), 316L (UNS S31603) — offering excellent corrosion resistance, formability, and weldability.
- Duplex Grades: 2205 (UNS S31803), 2507 (UNS S32750) — providing superior strength-to-weight ratios and resistance to chloride-induced stress corrosion cracking.
- Super-Austenitic Grades: 904L (UNS N08904) — designed for aggressive chemical environments.
- Martensitic & Ferritic Grades: 410, 430 — selected for applications requiring elevated hardness or magnetic properties.
Key mechanical properties include a minimum tensile strength (UTS) of 515 MPa for Grade 304, elongation of ≥40%, and a yield strength of ≥205 MPa. Chemical composition adheres to ASTM A213 / A269 and EN 10216-5 standards, with chromium (Cr) content typically ranging from 17%–25% and nickel (Ni) from 8%–22%, depending on the grade.
Specifications
| Parameter | Specification Range |
|---|---|
| Outer Diameter (OD) | 3.0 mm – 50.8 mm (1/8" – 2") |
| Wall Thickness (WT) | 0.3 mm – 3.0 mm |
| Coil Length (Continuous) | 1,000 m – 10,000 m (customizable) |
| Coil Inner Diameter (ID) | 200 mm – 600 mm |
| Surface Finish | Ba&R (Bright & Annealed), No. 1, 2B, 2D, Hairline, Mirror (No. 8) |
| Manufacturing Standard | ASTM A213, ASTM A269, EN 10216-5, GB/T 14976 |
| Available Grades | 304, 304L, 316, 316L, 321, 310S, 2205, 2507, 904L, 430, 410 |
| Maximum Production Speed | Up to 120 m/min (20 seconds per coil unit output) |
| Heat Treatment | Solution Annealing at 1050°C – 1150°C, followed by water quenching |
| Acceptance Tolerances | OD: ±0.05 mm; WT: ±0.03 mm; Straightness: ≤1 mm/m |
Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing follows a rigorously controlled, multi-stage process designed to ensure dimensional precision, metallurgical integrity, and surface quality:
- Raw Material Selection: Virgin stainless steel strip or wire rod is procured from certified mills, with mill test certificates (MTC) verified for chemical composition and mechanical properties.
- Coil Winding & Straightening: The raw strip is wound onto precision spools and fed through a high-speed straightening unit to eliminate residual curvature and ensure flatness within ±0.02 mm/m.
- Forming (Roll Forming or ERW): The flat strip is shaped into a tubular cross-section via multi-station roll forming or Electric Resistance Welding (ERW). The 20-second cycle time per unit is achieved through automated, continuous forming lines with servo-controlled roll stations.
- Welding & Seam Inspection: Where applicable, the longitudinal seam is welded using submerged arc or high-frequency induction methods. Seam integrity is verified by 100% ultrasonic testing (UT) or eddy current detection.
- Solution Annealing & Pickling: The formed tube undergoes solution annealing at 1050°C–1150°C to relieve residual stresses and homogenize microstructure, followed by acid pickling to remove oxide scale and restore surface finish.
- Passivation: A citric acid or nitric acid passivation treatment is applied to enhance corrosion resistance by forming a stable chromium oxide layer.
- Final Coiling & Packaging: The finished tube is recoiled onto protected spools, wrapped in moisture-barrier packaging, and labeled with batch traceability information.
The integration of automated high-speed forming lines enables a remarkable output rate — a single coil tube unit can be produced and dispatched from the line in as little as 20 seconds — dramatically reducing lead times and supporting just-in-time manufacturing workflows.
Applications
The versatility of stainless steel coil tubes renders them indispensable across multiple industrial sectors:
- HVAC & Refrigeration: Fan coil units, air handling units, condensers, and evaporators — where the high thermal conductivity and corrosion resistance of austenitic grades ensure long service life.
- Heat Exchangers: Shell-and-tube and plate-fin heat exchangers in power generation, petrochemical, and process industries.
- Food & Beverage Processing: Sanitary-grade tubing (304L/316L with electropolished finish) for dairy, brewery, and pharmaceutical piping systems compliant with FDA and EHEDG standards.
- Chemical & Petrochemical: Duplex and super-austenitic grades deployed in aggressive chemical transport, reactor internals, and offshore platforms.
- Automotive & Aerospace: Exhaust systems, fuel lines, and hydraulic circuits requiring high-temperature resistance and fatigue durability.
- Medical & Laboratory Equipment: Instrument tubing, endoscopy components, and sterilizable fluid delivery systems.
- Construction & Architectural: Structural tubing, railings, and decorative elements leveraging aesthetic surface finishes.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework to ensure product conformity and traceability:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing operations.
- ISO 14001:2015 — Environmental Management System ensuring sustainable and responsible production practices.
- ISO 45001:2018 — Occupational Health and Safety Management System.
- EN 10204 3.1 — Third-party inspection certificates available upon request, with independent testing by SGS, BV, or TÜV.
- Mill Test Certificates (MTC): Provided with every shipment, documenting chemical analysis, mechanical testing, and dimensional verification per batch.
- Non-Destructive Testing (NDT): 100% ultrasonic, eddy current, or hydrostatic pressure testing performed on all coil tube lots.
Unique Selling Points
- Ultra-High Throughput: Industry-leading 20-second-per-unit production cycle for coil tube output, enabling rapid fulfillment of large-scale orders.
- Grade Flexibility: Full spectrum of stainless steel grades available, from standard austenitic to advanced duplex and super-austenitic alloys.
- Dimensional Precision: Tight manufacturing tolerances (±0.05 mm OD, ±0.03 mm WT) ensure seamless integration into automated downstream processing.
- Full Traceability: Every coil is batch-coded with complete MTC documentation, enabling end-to-end material traceability for regulated industries.
- Customization Capability: Tailored coil dimensions, surface finishes, and heat treatment schedules available to meet specific application requirements.