Stainless Steel Coiled Tubing for Reactor Jacket Applications
Product Overview
The Stainless Steel Coiled Tubing (also referred to as Coiltube or Continuous-Length Coil Pipe) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered, cold-drawn stainless steel tube supplied in continuous coiled form. This product is specifically designed for integration into reactor jacket systems used in chemical, pharmaceutical, and bioprocessing industries, where thermal management, chemical resistance, and long-term operational reliability are paramount.
Unlike conventional straight-length piping, coiled tubing offers inherent advantages in flexibility, installation efficiency, and spatial adaptability within complex reactor jacket geometries. The continuous coil form factor minimizes the number of weld joints, thereby reducing potential leak points and enhancing the overall integrity of the thermal transfer system.
Material & Properties
Wenzhou Jixing Metal Materials Co., Ltd. produces coiled tubing from premium-grade austenitic stainless steels, selected to meet the rigorous demands of chemical cleaning and thermal cycling environments.
- Primary Grades: AISI 304 (UNS S30400), AISI 316 (UNS S31600), and AISI 316L (UNS S31603)
- Alternative Grades: AISI 321 (UNS S32100), AISI 347 (UNS S34700) for high-temperature service
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and intergranular corrosion, particularly in chloride-containing environments
- Chemical Cleaning Compatibility: The alloy composition ensures resistance to common chemical cleaning agents including nitric acid (HNO₃), hydrochloric acid (HCl), citric acid (C₆H₈O₇), and alkaline cleaning solutions (NaOH, Na₃PO₄)
- Temperature Range: Operational from cryogenic temperatures (−196 °C) to approximately 870 °C (304) / 925 °C (316L)
- Mechanical Properties: Tensile strength ≥ 515 MPa; Yield strength ≥ 205 MPa; Elongation ≥ 40% (annealed condition)
- Surface Finish: Mirror polished (Ra ≤ 0.05 μm) to sanitary electropolished (Ra ≤ 0.25 μm), suitable for pharmaceutical and food-grade applications
- Magnetism: Non-magnetic in annealed condition; minimal induced magnetism after cold working
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | 6.0 mm – 50.8 mm (¼" – 2") |
| Wall Thickness | 0.5 mm – 3.0 mm |
| Coil Inner Diameter | 300 mm – 600 mm |
| Coil Length | Continuous; typically 50 m – 500 m per coil |
| Manufacturing Standard | ASTM A269 / ASTM A270 / ASME B36.19M |
| Heat Treatment | Solution Annealed (1050 °C – 1150 °C, water quenched) |
| Surface Treatment | Pickled & Passivated; optional electropolishing |
| Tolerance (OD) | ±0.05 mm (precision grade) |
| Tolerance (Wall) | ±10% of nominal |
| Delivery Condition | Coiled, individually packaged with protective end caps |
| Chemical Cleaning Resistance | Qualified for repeated CIP (Clean-In-Place) and chemical acid washing cycles |
Manufacturing Process
The production of high-quality stainless steel coiled tubing follows a rigorous multi-stage manufacturing sequence designed to ensure dimensional precision, metallurgical integrity, and surface quality:
- Hot Rolling: Stainless steel slabs are hot-rolled into seamless or welded tube blanks to the approximate outer diameter and wall thickness requirements.
- Piercing & Stretch Reduction: For seamless tube production, the hot-rolled billet is pierced on a mandrel mill and subsequently stretch-reduced to achieve the final dimensional tolerances.
- Cold Drawing: The tube blank is cold-drawn through precision dies to achieve exact dimensions, improved mechanical properties, and superior surface finish. This process is critical for achieving the tight tolerances required in reactor jacket applications.
- Coiling: The continuously drawn tube is wound onto a precision coil former to produce the coiled configuration. Tension control during coiling ensures uniform coil geometry without deformation.
- Solution Annealing: The coiled tube undergoes solution annealing at 1050 °C – 1150 °C followed by controlled quenching to restore full austenitic microstructure, relieve cold-work stresses, and maximize corrosion resistance.
- Pickling & Passivation: The annealed tube is subjected to acid pickling (typically a mixed acid bath of HNO₃ and HF) to remove oxide scale, followed by passivation treatment to establish a stable, protective chromium oxide film on the surface.
- Optional Electropolishing: For sanitary and pharmaceutical applications, the tube interior and exterior may undergo electropolishing to achieve a mirror-smooth surface with Ra ≤ 0.05 μm, eliminating micro-crevices that could harbor bacterial contamination.
- Quality Inspection: Each coil undergoes comprehensive inspection including dimensional verification, hydrostatic pressure testing (typically 10–25 MPa), spectroscopic chemical analysis, and visual surface examination.
Applications
The coiled tubing manufactured by Wenzhou Jixing Metal Materials Co., Ltd. finds extensive application in the following domains:
- Chemical Reactor Jackets: The primary application involves thermal transfer jacket systems surrounding chemical reactors, where the coiled tubing forms the heating/cooling circuit. The chemical cleaning compatibility ensures the tubing withstands repeated acid washing cycles required for reactor decontamination between production batches.
- Pharmaceutical Processing: Used in jacketed reactors for fermentation, crystallization, and reaction processes where strict hygienic standards (FDA, EU GMP) must be maintained.
- Food & Beverage Industry: Applied in jacketed kettles, mixers, and heat exchangers where CIP (Clean-In-Place) systems employ aggressive chemical cleaning agents.
- Petrochemical & Refining: Utilized in heat exchanger bundles and reactor jacket cooling systems where resistance to sour gas (H₂S) and high-temperature service is required.
- Biochemical & Biotechnology: Employed in bioreactor jacket systems where repeated sterilization (SIP - Sterilize-In-Place) and chemical cleaning cycles demand exceptional material durability.
- Heat Exchanger Manufacturing: The coiled form factor is particularly advantageous for double-pipe heat exchangers and U-tube configurations, reducing fabrication labor and welding requirements.
Chemical Cleaning Compatibility — Technical Notes
The reactor jacket coiled tubing is specifically engineered to withstand the rigorous chemical cleaning protocols required in process industries. Key considerations include:
- Acid Washing: The tubing maintains its passive film integrity during exposure to dilute nitric acid (2–10% HNO₃), hydrochloric acid (≤10% HCl), and organic acids (citric acid, phosphoric acid) used in scale removal procedures.
- Alkaline Cleaning: Compatible with NaOH-based (2–5% concentration) and phosphate-based alkaline cleaning solutions used in CIP systems.
- Chloride Tolerance: Grade 316L coiled tubing exhibits excellent resistance to chloride-induced pitting, making it the preferred selection for reactor jackets handling chloride-containing process streams.
- Passivation Recovery: After chemical cleaning, the passive chromium oxide layer can be effectively restored through post-cleaning passivation treatment, ensuring long-term corrosion protection.
- Temperature Considerations: Chemical cleaning performance is enhanced at elevated temperatures (60 °C – 80 °C), within which the tubing maintains full mechanical and corrosion resistance properties.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and product certification portfolio to ensure compliance with international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO/TS 22163 — Medical Device Quality Management (for pharmaceutical-grade tubing)
- EN 10204 3.1 — Material Test Certificates provided with each shipment
- ASTM / ASME Compliance — Product manufactured and tested per ASTM A269, ASTM A270, and ASME B36.19M
- PED (Pressure Equipment Directive) — CE marking available for EU market compliance (Category II/III)
- NSF/ANSI 61 — Available for potable water contact applications
- 3-A Sanitary Standards — Available for food and dairy industry applications
Unique Selling Points
- Chemical Cleaning Durability: Specifically validated for repeated chemical cleaning cycles in reactor jacket applications, with proven resistance to both acidic and alkaline cleaning agents without degradation of the passive film.
- Continuous Coiled Configuration: Eliminates multiple butt welds required in straight-length pipe installations, reducing leak risk by up to 90% and simplifying installation in complex jacket geometries.
- Precision Dimensional Control: Tight tolerances (±0.05 mm OD) ensure reliable fit within reactor jacket channels and heat exchanger bundles without excessive clearance or interference.
- Full Traceability: Each coil is accompanied by a complete material traceability package including mill test certificates, chemical composition analysis, and mechanical test data per EN 10204 3.1.
- Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd. offers customized coil configurations, special alloy grades, and tailored surface finishes to meet specific customer application requirements.
- Hygienic Surface Finish: Mirror-polished and electropolished surfaces minimize product contact time and prevent microbial adhesion, meeting the most stringent sanitary requirements in pharmaceutical and food processing.