Stainless Steel Coil Tube (盘管) — Product Technical Specification
Product Code: 1217
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Category: Coil Tube / Coil Pipe (盘管)
1. Product Overview
The Stainless Steel Coil Tube (盘管) is a precision-engineered tubular component manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is designed in a continuous helical or spiral coil configuration, enabling high surface-area-to-volume ratios that are critical for heat exchange, fluid distribution, and chemical dosing applications. The coil tube is fabricated from high-grade austenitic stainless steel, offering superior corrosion resistance, mechanical integrity, and long-term thermal stability under demanding industrial conditions.
Wenzhou Jixing Metal Materials Co., Ltd. has accumulated extensive expertise in the design and manufacturing of stainless steel coil tubes, with particular proficiency in applications involving heating, cooling, and chemical solution preparation systems. The company's coil tube products have been successfully deployed in retrofitted cooling systems for chemical dosing tanks (配药罐), where reliable thermal management and material compatibility are paramount.
2. Material & Properties
2.1 Base Material Composition
The coil tube is typically fabricated from the following austenitic stainless steel grades, selected based on application-specific requirements:
- 304 (UNS S30408): General-purpose grade with excellent corrosion resistance in mild environments. Contains 18–20% Chromium (Cr) and 8–10% Nickel (Ni).
- 316 (UNS S31608): Enhanced corrosion resistance with 2–3% Molybdenum (Mo) addition, suitable for chloride-containing environments and chemical processing.
- 316L (UNS S31603): Low-carbon variant of 316, preferred for welded assemblies and high-purity applications where sensitization must be avoided.
- 321 (UNS S32108): Titanium-stabilized grade for elevated-temperature service (up to 870°C), resisting intergranular corrosion.
2.2 Key Material Properties
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, mild acids, alkalis, and organic/inorganic chemicals. The passive chromium oxide layer (Cr₂O₃) self-repairs in oxidizing environments.
- Thermal Conductivity: Approximately 16 W/(m·K) for 304 grade; 14 W/(m·K) for 316 grade — adequate for heat exchange coil applications.
- Thermal Expansion Coefficient: 17.3 × 10⁻⁶ /°C (304), 17.8 × 10⁻⁶ /°C (316) — requires consideration in thermal cycling designs.
- Mechanical Strength: Tensile strength ≥ 515 MPa (annealed 304); Yield strength ≥ 205 MPa.
- Temperature Range: Operational range from cryogenic temperatures (−196°C) up to 870°C (304) or 925°C (316) in oxidizing atmospheres.
- Hygienic Surface: Surface finish available in Ra ≤ 0.4 μm (electropolished) for pharmaceutical and food-grade applications.
3. Specifications
| Parameter | Specification / Range | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6 mm – 50 mm (custom sizes available) | ASTM A213 / GB/T 12771 |
| Wall Thickness (WT) | 0.5 mm – 3.0 mm | ASTM A269 / GB/T 13296 |
| Coil Diameter (CD) | 100 mm – 1000 mm | — |
| Coil Length (L) | Up to 50 m (continuous coil) | — |
| Surface Finish | No. 4 Brushed / BA (Bright Annealed) / Electropolished (Ra ≤ 0.4 μm) | ASTM A479 / GB/T 13318 |
| End Connection | Threaded (BSP/NPT), Flanged, Welded, or Socket | ASME B16.11 / GB/T 12459 |
| Pressure Rating | Up to 2.5 MPa (design dependent) | — |
| Operating Temperature | −196°C to +870°C | — |
| Material Grade | 304 / 304L / 316 / 316L / 321 | ASTM A270 / GB/T 13296 |
| Tolerance (OD) | ±0.1 mm (precision) / ±0.2 mm (standard) | ASTM A213 |
| Tolerance (WT) | ±10% | ASTM A269 |
4. Manufacturing Process
4.1 Raw Material Procurement
High-purity stainless steel seamless tubes conforming to ASTM A213/A269 or GB/T 12771/13296 are sourced from certified mills. Incoming material undergoes spectroscopic analysis (OES) to verify chemical composition and mechanical property testing to ensure compliance with specified grades.
4.2 Precision Cutting & Preparation
Raw tube stock is cut to specified lengths using precision plasma or laser cutting systems. Cut ends are deburred and chamfered to prevent stress concentration and facilitate welding or fitting attachment.
4.3 Coil Forming (Coiling)
The straight tube sections are cold-formed into helical coils using CNC-controlled coiling machinery. The forming process is carefully controlled to:
- Prevent excessive work hardening and maintain ductility
- Ensure uniform coil diameter and pitch throughout the length
- Avoid kinking, wrinkling, or ovality beyond acceptable tolerances
4.4 Welding & Assembly
For multi-section coils or configurations requiring end connections, welding is performed using:
- Orbital TIG (Tungsten Inert Gas) Welding: For circumferential welds with full penetration and consistent quality.
- Manual TIG Welding: For custom fittings and non-standard connections.
- Shielding Gas: Argon (Ar) or Helium (He) to prevent oxidation of the weld zone.
4.5 Surface Treatment & Finishing
- Pickling & Passivation: Removal of heat-affected discoloration and contamination, followed by passivation to restore the protective chromium oxide layer.
- Electropolishing: Available for high-purity applications, achieving surface roughness Ra ≤ 0.4 μm and enhancing corrosion resistance.
- Chemical Cleaning: Final cleaning with food-grade or industrial-grade cleaners to remove all residues.
4.6 Quality Inspection
Each coil tube undergoes comprehensive inspection prior to shipment:
- Dimensional Inspection: OD, WT, coil diameter, and length verified with calibrated instruments.
- Visual Inspection (VT): 100% examination for surface defects, weld quality, and overall integrity.
- Pressure Testing: Pneumatic or hydraulic testing at 1.5× design pressure for a minimum of 15 minutes.
- Chemical Analysis: Spectroscopic verification of material grade (OES or XRF).
- Non-Destructive Testing (NDT): Penetrant testing (PT) or eddy current testing (ECT) for critical welds.
5. Applications
The Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. is deployed across a broad spectrum of industrial applications:
- Chemical Dosing & Solution Preparation (配药罐系统): Coil tubes serve as heating or cooling elements within chemical dosing tanks, enabling precise temperature control of prepared solutions. The company's experience includes successful cooling retrofit projects for coil-heated chemical dosing tanks, demonstrating expertise in thermal management optimization.
- Heat Exchangers: Spiral coil heat exchangers for liquid-liquid and liquid-gas heat transfer in chemical, petrochemical, and power generation industries.
- Pharmaceutical Processing: Sanitary-grade coil tubes for CIP (Clean-In-Place) heating systems, reactor jacket coils, and sterile fluid handling.
- Food & Beverage Industry: Heating and cooling coils for pasteurization, sterilization, and temperature-controlled storage systems.
- Water Treatment: Coil tubes used in heating elements for water treatment plants, desalination systems, and boiler feedwater preparation.
- Oil & Gas: Subsea coil tubing for oil well completion, acidizing, and stimulation operations (using 316L grade).
- Heating & HVAC Systems: Coil elements for industrial heating systems, thermal oil loops, and process heating applications.
- Power Generation: Tubular heating elements and cooling coils in thermal power plants and nuclear facilities.
6. Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and certifications to ensure product reliability and international compliance:
- ISO 9001:2015: Quality Management System certification ensuring consistent product quality and process control.
- ISO 14001: Environmental Management System certification for sustainable manufacturing practices.
- ISO 45001: Occupational Health and Safety Management System certification.
- CE Marking: Conformity with European Union directives for pressure equipment and machinery.
- ASME (American Society of Mechanical Engineers): Compliance with ASME B31.3 (Process Piping) and ASME Section VIII (Pressure Vessels) where applicable.
- GB Standards (Chinese National Standards): Full compliance with GB/T 12771, GB/T 13296, GB/T 13318, and related specifications.
- ASTM Standards: Material and dimensional compliance with ASTM A213, A269, A270, and A479.
- EN Standards (European): Compliance with EN 10216-5 and EN 10217-7 for stainless steel tubes.
7. Unique Selling Points
- Application-Specific Engineering: Deep expertise in thermal management applications, particularly in chemical dosing tank cooling and heating retrofits, providing optimized coil geometries for maximum heat transfer efficiency.
- Customizable Configurations: Full customization of coil diameter, pitch, tube dimensions, end connections, and surface finish to meet specific project requirements.
- Material Expertise: Proficiency in selecting and processing multiple stainless steel grades (304, 316, 316L, 321) to match specific corrosion and temperature requirements.
- End-to-End Quality Assurance: Comprehensive inspection protocols including material verification, dimensional control, pressure testing, and NDT ensure zero-defect delivery.
- Proven Retrofit Capability: Demonstrated success in modifying existing heating systems to cooling configurations, offering solutions that improve process efficiency and safety.
- Cost-Effective Solutions: Competitive pricing without compromising on material quality or manufacturing standards, leveraging direct manufacturing capabilities.
This technical specification is intended for reference purposes. For detailed product inquiries, custom design requirements, or project-specific consultations, please contact Wenzhou Jixing Metal Materials Co., Ltd. directly.