Stainless Steel Coil Tube — Wenzhou Jixing Metal Materials Co., Ltd.
Product Code: No. 961 | Classification: Technical Reference 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 a continuous coil configuration. This product is designed to meet the demanding requirements of industrial applications where corrosion resistance, mechanical integrity, and dimensional accuracy are paramount. The coil tube is produced through advanced cold-drawing and coiling processes, resulting in a seamless tubular product with superior surface finish and consistent wall thickness throughout its length.
The coiled configuration offers significant logistical advantages, enabling continuous feeding into downstream processing equipment such as tube cutting machines, bending stations, and welding systems. This makes the product particularly suitable for high-volume manufacturing environments where uninterrupted material flow is essential for productivity optimization.
Material & Properties
Material Grades
- Austenitic Stainless Steels: Grades 304 (UNS S30400), 304L (UNS S30403), 316 (UNS S31600), and 316L (UNS S31603)
- Duplex Stainless Steels: Grade 2205 (UNS S32205) available upon request
- Super Austenitic Grades: 904L (UNS N08904) for extreme corrosion environments
Mechanical Properties
- Tensile Strength (Ultimate Tensile Strength, UTS): ≥ 520 MPa (Grade 304), ≥ 550 MPa (Grade 316)
- Yield Strength (0.2% Proof Stress): ≥ 205 MPa
- Elongation at Break: ≥ 40% (minimum)
- Hardness: ≤ 210 HB (annealed condition)
- Impact Toughness: ≥ 27 J at −40°C (Charpy V-Notch)
Corrosion Resistance
- Excellent resistance to atmospheric corrosion and general chemical attack
- Grade 316/316L provides superior resistance to chlorides, acids, and marine environments
- Resistance to pitting and crevice corrosion governed by the Corrosion Resistance Index (CRI) and Pitting Resistance Equivalent Number (PREN) ≥ 26
- Resistance to intergranular corrosion (IGC) verified per ASTM A240/A240M
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6.0 mm – 108.0 mm | ASTM A554 / EN 10216-5 |
| Wall Thickness (WT) | 0.5 mm – 6.0 mm | ASTM A554 / EN 10216-5 |
| OD Tolerance | ±0.05 mm (precision grade); ±0.10 mm (standard grade) | ISO 13070 |
| Wall Thickness Tolerance | ±10% of nominal (standard); ±5% (precision grade) | ISO 13070 |
| Coil Inner Diameter | 150 mm – 300 mm | Manufacturer Specification |
| Coil Length per Spool | 100 m – 500 m (configurable) | — |
| Surface Finish | 2B (Cold Rolled & Annealed); BA (Bright Annealed); No. 4 Brushed; No. 8 Mirror Polish | ASTM A480 / GB/T 343 |
| Surface Roughness (Ra) | ≤ 0.8 μm (2B); ≤ 0.4 μm (BA); ≤ 0.2 μm (Mirror) | ISO 1302 |
| Heat Treatment Condition | Solution Annealed (1050°C – 1150°C, water quenched) | ASTM A270 |
| Maximum Operating Temperature | 870°C (Grade 304); 870°C (Grade 316) | ASME BPV Code |
| Minimum Operating Temperature | −196°C (cryogenic capable) | — |
| Packaging | Wooden crate / Steel banding with moisture barrier; export-grade protection | ISO 4180 |
Manufacturing Process
- Raw Material Selection: Virgin stainless steel strip or hot-rolled coil sourced from certified mill suppliers, with full chemical composition verification via spectroscopic analysis (OES — Optical Emission Spectroscopy).
- Decoiling & Leveling: Incoming coil material is uncoiled and passed through a precision leveling machine to eliminate coil set and ensure flatness prior to tube forming.
- Tube Forming (Seamless or Welded): The flat strip is formed into tubular geometry through either:
- Seamless process: Extrusion or piercing followed by cold drawing for high-precision dimensions.
- Welded process: Roll-forming into a C-shape, followed by high-frequency induction welding (HFW — High Frequency Welding) or TIG welding for joint integrity.
- Pipe Milling & Sizing: Precision rotary piercing or cold drawing to achieve exact outer diameter and wall thickness tolerances.
- Solution Annealing: Tubes are heated to 1050°C – 1150°C in a controlled-atmosphere furnace (nitrogen or vacuum) and rapidly quenched to achieve a fully solution-annealed microstructure, ensuring maximum corrosion resistance and ductility.
- Pickling & Passivation: Surface treatment to remove scale, oxide layers, and contamination. Passivation treatment establishes a chromium-rich oxide layer for enhanced passive film stability.
- Surface Finishing: Polishing, brushing, or bright annealing to achieve the specified surface finish grade.
- Coiling: The finished tube is wound onto a precision coil former to create the final coil configuration, with controlled tension to prevent deformation or kinking.
- Quality Inspection: Comprehensive inspection including visual examination, dimensional verification (laser measurement), hydrostatic or pneumatic pressure testing, and non-destructive testing (EDDY — Eddy Current Testing; UT — Ultrasonic Testing).
- Packaging & Marking: Each coil is labeled with product identification, heat number, grade, dimensions, and compliance documentation.
Applications
- Heating, Ventilation & Air Conditioning (HVAC): Fan coil units, chiller coils, condenser tubes, and heat exchanger assemblies where thermal efficiency and corrosion resistance are critical.
- Food & Beverage Industry: Sanitary piping, brewing systems, dairy processing equipment, and CIP (Clean-In-Place) compatible transfer lines.
- Pharmaceutical Manufacturing: GMP-compliant process piping, reactor internals, and sterile fluid transfer systems requiring electropolished surfaces.
- Chemical Processing: Acid and chemical transfer lines, reactor coil internals, and corrosion-resistant heat exchangers.
- Marine & Offshore: Seawater cooling systems, ballast water treatment, and offshore platform piping where chloride resistance is essential.
- Automotive Industry: Precision fuel lines, exhaust system components, and hydraulic tubing for high-performance vehicles.
- Energy & Power Generation: Solar thermal collectors, geothermal heat exchangers, and nuclear-grade process tubing.
- Medical Devices: Endoscopy tubing, surgical instrument shafts, and implant-grade component fabrication.
Quality Certifications & Compliance
| Certification / Standard | Description |
|---|---|
| ISO 9001:2015 | Quality Management System certification ensuring consistent product quality and process control. |
| ISO 14001:2015 | Environmental Management System certification for sustainable manufacturing practices. |
| ISO 45001:2018 | Occupational Health & Safety Management System compliance. |
| EN 10204 3.1 | Material test certificates with independent inspection body verification. |
| ASME BPV Code Section VIII | Compliance for pressure vessel and piping applications. |
| ASTM A554 / A554M | Standard specification for seamless and welded austenitic stainless steel tubing. |
| GB/T 12771 | Chinese national standard for seamless stainless steel tubes for general purposes. |
| PED 2014/68/EU | European Pressure Equipment Directive compliance for applicable pressure-rated applications. |
| NACE MR0175 / ISO 15156 | Resistance to sulfide stress cracking for oil and gas industry applications. |
Unique Selling Points
- Continuous Coil Configuration: Eliminates butt welds and joints inherent in straight-length tubing, reducing potential failure points and minimizing material waste during downstream fabrication.
- Precision Dimensional Control: Tight tolerance manufacturing (±0.05 mm OD) ensures reliable fit-up in automated assembly systems and reduces secondary machining requirements.
- Multi-Grade Availability: Comprehensive range of stainless steel grades accommodates diverse environmental and performance requirements from a single supplier.
- Full Traceability: Each coil is associated with a unique heat number and accompanied by mill test certificates (MTC — Mill Test Certificate), enabling complete material traceability throughout the supply chain.
- Custom Configuration: Flexible customization of coil diameter, tube dimensions, surface finish, and packaging to meet specific customer requirements.
- Comprehensive Testing: Multi-stage quality assurance including chemical analysis, mechanical testing, dimensional inspection, hydrostatic testing, and non-destructive examination ensures conformance to the highest quality standards.
Technical Notes
Users should note that the coiled configuration of this product is optimized for continuous processing applications. For applications requiring discrete lengths with machined ends, the coil tube can be cut and end-prepared to specification. Storage should be in a dry, well-ventilated environment away from dissimilar metals to prevent galvanic corrosion and contamination. Handling should utilize appropriate equipment to avoid coil unwinding or deformation.
For HVAC-specific applications, this coil tube product is compatible with integrated temperature control systems utilizing microcontroller-based controllers (e.g., MSP430-based platforms) for precise thermal management of fan coil units and related heat exchange systems. The combination of the tube's thermal conductivity properties and corrosion resistance makes it an ideal medium for refrigerant or hydronic fluid circulation in precision climate control applications.