Stainless Steel Coil Tube (Coiltube) — Product Technical Specification
1. Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered continuous-length tubular product wound into a compact coil configuration. This product category is specifically designed for applications requiring long, uninterrupted runs of tubing without the joints or welds associated with straight-length pipe sections. The coil tube geometry provides inherent flexibility during installation while maintaining the mechanical integrity and corrosion resistance characteristic of stainless steel alloys.
Coil tubes are extensively utilized in thermal energy systems, including solar water heating collectors, heat exchangers, refrigeration circuits, and fluid distribution networks. The coiled form factor minimizes material waste, reduces handling damage, and enables efficient transportation and storage compared to equivalent-length straight pipe segments.
2. Material Composition & Properties
Wenzhou Jixing Metal Materials Co., Ltd. produces coil tubes in a range of austenitic and duplex stainless steel grades, each selected to address specific environmental and mechanical demands:
- AISI 304 (UNS S30400) — General-purpose corrosion resistance; suitable for food-grade, chemical, and architectural applications.
- AISI 316L (UNS S31603) — Enhanced chloride and pitting resistance due to molybdenum (Mo) content of 2.0–2.5%; preferred for marine and aggressive chemical environments.
- AISI 321 (UNS S32100) — Stabilized with titanium (Ti); excellent resistance to intergranular corrosion at elevated temperatures (up to 870 °C).
- AISI 310S (UNS S31008) — High-temperature oxidation resistance; suitable for furnace components and thermal processing equipment.
- Super Duplex 2205 (UNS S31803) — Combined high strength (yield strength ≥ 450 MPa) and superior chloride stress corrosion cracking resistance.
3. Technical Specifications
| Parameter | Specification / Range |
|---|---|
| Outer Diameter (OD) | 3.0 mm – 50.8 mm (⅛" – 2") |
| Wall Thickness (WT) | 0.3 mm – 3.0 mm |
| Coil Length | 15 m – 200 m per coil (configurable) |
| Coil Inner Diameter (CID) | 200 mm – 1,200 mm |
| Tolerance on OD | ±0.05 mm (precision grade); ±0.1 mm (standard grade) |
| Tolerance on Wall Thickness | ±10% of nominal |
| Surface Finish | 2B (cold-rolled), BA (Bright Annealed), No. 4 Brushed, Mirror (#1A/#8) |
| End Condition | Plain cut, beveled, or threaded (on request) |
| Applicable Standards | ASTM A269, ASTM A270, EN 10217-7, GB/T 12771, JIS G3459 |
| Operating Temperature Range | −196 °C to +1,150 °C (grade-dependent) |
| Maximum Working Pressure | Up to 40 MPa (subject to grade and dimensions) |
4. Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorously controlled multi-stage process:
- Raw Material Procurement — Certified stainless steel strip (cold-rolled coil) sourced from accredited mills with full chemical and mechanical traceability.
- Edge Trimming & Surface Preparation — Precision edge machining to eliminate burrs and surface defects that could compromise weld quality.
- Forming & Welding — The strip is formed into a tubular geometry and joined via a high-frequency resistance welding (HFRW) or orbital TIG welding process, ensuring a continuous, uniform weld seam with minimal heat-affected zone.
- Heat Treatment (Annealing) — Post-weld solution annealing at temperatures between 1,010 °C and 1,150 °C followed by controlled cooling to restore full austenitic microstructure and eliminate residual stresses.
- Pickling & Passivation — Acid pickling (HNO₃/HF blend) to remove oxide scale, followed by nitric acid passivation to establish a protective chromium oxide passive film.
- Dimensional Inspection — Automated gauging of outer diameter, wall thickness, and straightness tolerance using laser-based measurement systems.
- Coiling & Packaging — The continuous tube is wound onto a spool with appropriate protective wrapping (PE film, paper wrap, or wooden crate) to prevent mechanical damage and moisture exposure during transit.
5. Applications
The coil tube product line serves a diverse range of industrial and commercial sectors:
- Solar Thermal Systems — Evacuated tube solar collectors, flat-plate heat collectors, and large-area solar water heating systems where continuous tubing eliminates leakage points and maximizes heat transfer efficiency.
- Heat Exchangers & Condensers — Double-pipe heat exchangers, plate-and-frame assemblies, and shell-and-tube configurations in HVAC and process cooling.
- Refrigeration & Air Conditioning — Capillary tubes, expansion coils, and refrigerant distribution lines operating under cryogenic conditions.
- Food & Beverage Processing — Sanitary fluid transfer lines, CIP (Clean-in-Place) systems, and pasteurization circuits requiring hygienic-grade surfaces.
- Chemical & Petrochemical — Corrosive fluid transport, reactor cooling loops, and distillation column internals.
- Automotive & Aerospace — Fuel lines, hydraulic circuits, and exhaust system components requiring high-temperature and vibration resistance.
- Medical Equipment — Endoscope guide tubes, infusion lines, and sterilization-compatible fluid pathways.
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains the following quality management and product certifications:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing and supply chain operations.
- ISO 14001:2015 — Environmental Management System ensuring sustainable production practices.
- CE Marking (EU) — Conformity with European directives for pressure equipment (PED 2014/68/EU) where applicable.
- EN 10204 3.1 Certificates — Third-party inspection and material certification for each production batch.
- Mill Test Reports (MTR) — Full chemical composition and mechanical property documentation traceable to the heat number.
- NSF/ANSI 61 — Drinking water system component compliance (for food-grade and potable water applications).
7. Unique Selling Points
- Seamless Continuity — The coil format provides uninterrupted tube length, eliminating field welds and reducing the risk of leak points in critical service.
- Customizable Geometry — Outer diameter, wall thickness, coil length, and coil inner diameter are all configurable to meet project-specific engineering requirements.
- Multi-Grade Availability — A comprehensive material portfolio spanning standard austenitic grades to super duplex alloys enables optimal material selection for any corrosive or thermal environment.
- Precision Tolerances — Automated dimensional control ensures consistent geometry, facilitating reliable press-fit, brazed, and orbital-welded connections downstream.
- Full Traceability — Each coil is traceable to its raw material heat, manufacturing lot, and inspection records, supporting regulatory compliance in pharmaceutical, aerospace, and nuclear industries.
- Scalable Production — Capability to supply both small-batch custom orders and high-volume production runs, supported by flexible manufacturing capacity.
8. Conclusion
The Stainless Steel Coil Tube product line from Wenzhou Jixing Metal Materials Co., Ltd. represents a high-performance solution for engineers and procurement specialists seeking reliable, corrosion-resistant, continuous-length tubing for thermal, fluid handling, and structural applications. The combination of precision manufacturing, comprehensive material options, rigorous quality assurance, and adherence to international standards positions this product as a dependable component in demanding industrial systems.