Stainless Steel Coil Tube — Product Technical Specification
1. Product Overview
The Stainless Steel Coil Tube (Product No. 1200) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This coil tube is supplied in continuous coil form, offering flexibility in downstream processing, cutting, forming, and installation. The product is designed for applications demanding high corrosion resistance, mechanical integrity, and hygienic performance. As a coiled configuration, it enables efficient material utilization and minimizes waste during fabrication, making it particularly suitable for high-volume production environments including HVAC (Heating, Ventilation, and Air Conditioning) systems, fluid conveying networks, and structural assemblies.
2. Material & Properties
2.1 Base Material
The coil tube is fabricated from austenitic stainless steel, predominantly conforming to grades such as AISI 304 (UNS S30400) and AISI 316L (UNS S31603). These grades provide excellent resistance to pitting, crevice corrosion, and general atmospheric degradation due to their chromium (Cr) and nickel (Ni) alloying content.
2.2 Key Mechanical Properties
- Tensile Strength: 515–720 MPa (depending on grade and cold-work condition)
- Yield Strength (0.2% offset): ≥205 MPa
- Elongation at Break: ≥40% (annealed condition)
- Hardness: 80–120 HRB (annealed condition)
- Operating Temperature Range: −196 °C to +870 °C (304 grade); −196 °C to +870 °C (316L grade)
2.3 Corrosion Resistance
- Outstanding resistance to atmospheric corrosion and oxidizing acids
- 316L grade provides enhanced resistance to chlorides and marine environments
- Low carbon content (316L: ≤0.03% C) minimizes intergranular corrosion risk during welding
2.4 Surface Finish Options
- No. 1 (Hot-rolled annealed and pickled)
- 2B (Cold-rolled, annealed, and bright pickled)
- No. 4 (Brushed / Satin finish)
- Mirror finish (Ra ≤ 0.4 μm)
- Electropolished (Ra ≤ 0.25 μm) for hygienic applications
3. Specifications
| Parameter | Specification |
|---|---|
| Product Name | Stainless Steel Coil Tube (盘管 / Coil Tube) |
| Product No. | 1200 |
| Material Grades | AISI 304, 304L, 316, 316L, 321, 310S (custom available) |
| Outer Diameter (OD) | 3.0 mm – 108 mm (custom sizes available) |
| Wall Thickness (WT) | 0.3 mm – 6.0 mm |
| Coil Inner Diameter | 200 mm / 300 mm / 500 mm (configurable) |
| Coil Length | 15 m – 100 m per coil (or continuous supply) |
| Dimensional Tolerance (OD) | ±0.1 mm – ±0.5 mm (per ASTM A213 / GB/T 14976) |
| Dimensional Tolerance (WT) | ±10% of nominal |
| End Condition | Plain / Beveled / Threaded / Flanged |
| Manufacturing Method | ERW (Electric Resistance Welding) / Seamless / Laser Welding |
| Standards | ASTM A213/A213M, ASME SA-213, GB/T 14976, EN 10216-5 |
| Packaging | Export-grade wooden crate / steel band bundling with moisture-proof wrapping |
4. Manufacturing Process
The production of stainless steel coil tubes follows a rigorous multi-stage manufacturing workflow designed to ensure dimensional accuracy, metallurgical homogeneity, and surface quality:
- Strip Preparation: Cold-rolled stainless steel strip is inspected for surface defects and compositional conformity.
- Forming (Rolling): The strip is passed through a series of precision roll stands to progressively form the desired tube cross-section (round, rectangular, or oval).
- Welding: ERW or laser welding is employed to close the seam, producing a fusion bond with minimal heat-affected zone (HAZ) distortion.
- Heat Treatment: Solution annealing at 1050–1150 °C followed by rapid quenching to achieve full austenitic microstructure and maximum corrosion resistance.
- Pickling & Passivation: Removal of oxide scale and formation of a protective chromium oxide passive layer.
- Coiling & Inspection: The finished tube is wound into coils and subjected to 100% visual inspection, dimensional verification, and hydrostatic pressure testing.
5. Applications
The Stainless Steel Coil Tube (No. 1200) is engineered for versatility across multiple industrial sectors:
- HVAC Systems: Fan coil units (FCUs), air handling units, refrigeration condensers, and evaporators. The coil tube configuration is particularly suited for indoor pollutant concentration management in fan coil + fresh air systems, where thermal exchange efficiency and hygienic surface properties are critical for maintaining indoor air quality (IAQ).
- Fluid Conveyance: Water supply, chemical processing, food and beverage transfer, and pharmaceutical piping systems.
- Automotive & Aerospace: Exhaust systems, fuel lines, and hydraulic circuits requiring high-temperature and corrosion-resistant tubing.
- Medical Equipment: Endoscopy instrument channels, dialysis tubing, and sterilization equipment.
- Architectural & Decorative: Structural handrails, furniture frames, and building facades.
- Energy Sector: Solar thermal collectors, heat exchanger bundles, and geothermal well casings.
6. Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring product conformity to international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- CE Marking — European Conformity compliance
- EN 10204 3.1 — Material Test Certificate (MTC) issued for every batch
- ASTM / ASME — Product conformance to North American standards
- GB/T — Chinese national standard compliance for domestic market
Each production lot undergoes non-destructive testing (NDT) including eddy current inspection and dye penetrant testing (DPT) to guarantee seam integrity. Chemical composition analysis (spectrometry) and mechanical property verification (tensile testing, hardness testing) are performed in accordance with applicable standards.
7. Unique Selling Points
- Continuous Coil Supply: Eliminates butt-weld joints in downstream fabrication, reducing leak points and improving structural continuity.
- Wide Size Range: Customizable OD and wall thickness accommodate diverse engineering requirements from micro-tubing to large-diameter process pipes.
- HVAC-Optimized Design: Particularly suited for fan coil unit applications where efficient heat transfer, low pressure drop, and resistance to condensation-induced corrosion are paramount for managing indoor pollutant distribution.
- Hygienic Grade Available: Electropolished surfaces with Ra ≤ 0.25 μm suitable for pharmaceutical and food-grade applications.
- Full Traceability: Each coil is marked with heat number, grade, dimensions, and production date for complete supply chain traceability.