Special Ni-Material Coil Tube for Heated Spiral Plate Condenser (Coiltube)
Product Reference No.: 506 | Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The Special Ni-Material Coil Tube (Coiltube) is a precision-engineered stainless steel tubing product specifically designed for integration into heated spiral plate condensers (Spiral Plate Heat Exchangers with Coil-Tube Heating). This product represents an advanced solution in heat exchange technology, combining the high corrosion resistance and thermal conductivity of nickel-based stainless steel alloys with the geometric efficiency of coiled configurations. The coil tube serves as the heat transfer medium within spiral plate condenser assemblies, enabling superior thermal performance in demanding industrial environments.
The product is manufactured in accordance with international metallurgical standards and is engineered to withstand extreme operating conditions including high temperatures, aggressive chemical media, and cyclic thermal loading. Its helical geometry maximizes surface-area-to-volume ratio, facilitating efficient heat dissipation or absorption within the condenser system.
2. Material & Properties
2.1 Base Material Composition
The coil tube is fabricated from specialty nickel-enhanced stainless steel grades, selected for their exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC). Typical alloy designations include:
- 316L Stainless Steel (UNS S31603): Low-carbon variant with enhanced weldability and corrosion resistance
- 310S Stainless Steel (UNS S31008): High-temperature grade with superior oxidation resistance up to 1093°C (2000°F)
- Custom Ni-Alloy Blends: Tailored compositions with elevated nickel (Ni) content (8–25 wt%) for specialized applications
2.2 Key Mechanical Properties
| Property | Specification | Test Standard |
|---|---|---|
| Tensile Strength (UTS) | ≥ 520 MPa (75,400 psi) | ASTM A240 / GB/T 24511 |
| Yield Strength (0.2% offset) | ≥ 205 MPa (29,700 psi) | ASTM A240 / GB/T 24511 |
| Elongation at Break | ≥ 40% | ASTM A240 |
| Hardness (HBW) | ≤ 220 HBW | ISO 6506 |
| Thermal Conductivity (25°C) | 14–16 W/(m·K) | ASTM E1225 |
| Thermal Expansion Coefficient (20–100°C) | 17.3 × 10⁻⁶ /°C | ASTM E228 |
2.3 Corrosion Resistance Characteristics
- Excellent resistance to atmospheric corrosion and mild acid environments
- High resistance to chlorinated media (chloride ion content up to 500 ppm)
- Outstanding performance in oxidizing and reducing acidic environments
- Resistance to intergranular corrosion after welding (due to low carbon content ≤ 0.03%)
- Pitting Resistance Equivalent Number (PREN) ≥ 24
3. Specifications
| Parameter | Specification |
|---|---|
| Product Name | Coiltube (Spiral Coil Tube) |
| Reference No. | 506 |
| Outer Diameter (OD) | Φ6.0 mm – Φ25.0 mm (customizable) |
| Wall Thickness | 0.5 mm – 3.0 mm |
| Coil Pitch | 3.0 mm – 15.0 mm (configurable per design requirements) |
| Coil Length | Up to 50,000 mm per continuous coil (spooled) |
| Coil Forming Diameter | Min. bending radius ≥ 5× OD |
| Surface Finish | Ba ≤ 0.5 μm (electropolished) or Ra ≤ 0.8 μm (mechanically polished) |
| Dimensional Tolerance | ±0.05 mm (OD), ±0.02 mm (wall thickness) |
| Operating Temperature Range | −196°C to +1100°C (depending on grade) |
| Operating Pressure | Up to 25 MPa (3,625 psi) |
| End Treatment | Plain end, beveled, threaded, or socket-weld preparation |
| Packaging | Anti-corrosion wrapping, wooden crate or steel drum |
4. Manufacturing Process
The production of the Special Ni-Material Coil Tube involves a multi-stage, precision-controlled manufacturing sequence:
- Raw Material Selection & Inspection: Virgin stainless steel billets or strip stock sourced from certified mills, subjected to spectrographic analysis (OES) for chemical composition verification.
- Hot Rolling / Cold Drawing: Initial tube forming via hot extrusion or cold drawing to achieve precise OD and wall thickness tolerances.
- Heat Treatment (Solution Annealing): Controlled annealing at 1050–1150°C followed by rapid water quenching to achieve full solution treatment, eliminating carbide precipitation at grain boundaries.
- Precision Coiling (Helical Forming): Computer-controlled CNC coiling equipment forms the straight tube into a helical spiral configuration with uniform pitch and controlled residual stress. The coiling process is performed at ambient temperature (cold forming) or elevated temperature (warm forming) depending on material grade and coil geometry requirements.
- Surface Treatment: Electropolishing or mechanical polishing to achieve the specified surface roughness, critical for minimizing fouling and maximizing heat transfer efficiency.
- Non-Destructive Testing (NDT): 100% inline ultrasonic testing (UT), eddy current testing (ECT), and hydrostatic pressure testing (at 1.5× working pressure for 30 minutes minimum) to ensure structural integrity.
- Final Dimensional Inspection: Coordinate Measuring Machine (CMM) verification of coil geometry, pitch consistency, and dimensional conformance.
5. Applications
The Special Ni-Material Coil Tube is engineered for the following critical industrial applications:
- Spiral Plate Condensers (Heated Type): Primary application — the coil tube functions as the heat transfer element within spiral plate heat exchanger assemblies, providing efficient condensation of process vapors.
- Petrochemical Processing: Condensation and heat recovery in refining units, distillation columns, and process vapor handling systems.
- Pharmaceutical & Food Processing: Sanitary-grade heat exchange systems requiring high purity and corrosion resistance.
- Power Generation: Waste heat recovery systems, economizers, and auxiliary condensation units.
- Marine & Offshore Engineering: Seawater-cooled condensers where chloride resistance is paramount.
- Chemical Processing: Handling of aggressive chemical media including acids, alkalis, and halogenated compounds.
6. Quality Certifications & Standards Compliance
The product is manufactured under a comprehensive quality management system with the following certifications and standards compliance:
| Certification / Standard | Description |
|---|---|
| ISO 9001:2015 | Quality Management System certification |
| ISO 14001:2015 | Environmental Management System certification |
| ISO 45001:2018 | Occupational Health and Safety Management System |
| EN 10204 Type 3.1 | Test Report with detailed chemical and mechanical data |
| ASTM A213 / A269 | Standard specification for seamless austenitic stainless steel tubing |
| ASTM A240 | Standard specification for chromium and chromium-nickel stainless steel plate |
| GB/T 12771 | National standard for stainless steel welded tubes for general applications |
| GB/T 24511 | National standard for pressure vessels — materials, design, and fabrication |
| ASME BPV Section II | Materials for pressure vessels (where applicable) |
| PED 2014/68/EU | Pressure Equipment Directive compliance (European market) |
7. Unique Selling Points
The Special Ni-Material Coil Tube distinguishes itself through the following competitive advantages:
- Superior Thermal Efficiency: The helical coil geometry combined with nickel-enhanced alloy composition achieves heat transfer coefficients 15–25% higher than conventional straight-tube designs.
- Extended Service Life: Nickel content elevation provides exceptional resistance to stress corrosion cracking and chloride-induced pitting, extending operational life beyond 15 years in aggressive environments.
- Customizable Geometry: Full parametric design capability for coil pitch, diameter, and length to optimize performance for specific condenser configurations.
- Integrated Manufacturing: End-to-end production from raw material to finished coil tube under single-site quality control, ensuring traceability and consistency.
- Wide Grade Selection: Available in multiple stainless steel grades (316L, 310S, 321, 347H, custom Ni-alloys) to match specific operating conditions and media compatibility requirements.
- Full Traceability: Every coil tube batch is accompanied by complete material traceability documentation, heat number identification, and third-party inspection reports.
8. Conclusion
The Special Ni-Material Coil Tube (Reference No. 506) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. represents a state-of-the-art solution for heated spiral plate condenser applications. Its combination of metallurgical excellence, precision manufacturing, and geometric optimization makes it an ideal choice for engineers and procurement specialists seeking reliable, high-performance heat exchange components in demanding industrial environments. The product embodies the convergence of advanced materials science and precision tube forming technology, delivering measurable improvements in thermal performance, operational reliability, and total cost of ownership.