Stainless Steel Spiral Coil Tube — Coiltube (Model No. 1402)
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd. (温州吉星金属材料有限公司)
Product Category: Literature & Technical Learning Reference — Spiral Coil Water Jacket Furnace Application
Classification: Literature Study (一级分类: 文献学习)
1. Product Overview
The Spiral Coil Tube (盘管 Coiltube), designated as Model No. 1402, is a precision-engineered stainless steel tubing product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is specifically designed for integration into Spiral Coil Water Jacket Furnaces (螺旋盘管水套炉), a specialized thermal processing system widely employed in petrochemical, power generation, and industrial heating applications.
The coil tube serves as the critical heat exchange and fluid circulation medium within the furnace system. Its spiral geometry maximizes the surface-area-to-volume ratio, enabling highly efficient heat transfer between the combustion chamber and the circulating working fluid (typically water or steam). Wenzhou Jixing Metal Materials Co., Ltd. applies rigorous metallurgical standards and advanced forming technologies to ensure the coil tube meets the demanding requirements of high-temperature, high-pressure, and corrosive operating environments.
The knowledge base associated with this product (Reference No. 1402) encompasses technical documentation, operational guidelines, and engineering insights derived from the study and implementation of spiral coil water jacket furnace systems, providing comprehensive guidance for design, installation, and maintenance personnel.
2. Material & Properties
2.1 Material Grades
The coil tube is fabricated from high-performance austenitic stainless steel grades, selected based on the specific thermal and chemical demands of the application:
- SAE 304 (UNS S30408): General-purpose grade with excellent corrosion resistance, suitable for moderate temperature applications up to approximately 870°C (1,600°F).
- SAE 316L (UNS S31603): Enhanced grade with molybdenum addition, providing superior resistance to pitting and crevice corrosion in chloride-containing environments. Recommended for petrochemical and marine-related furnace applications.
- SAE 321 (UNS S32100): Titanium-stabilized grade offering excellent resistance to intergranular corrosion and suitable for sustained high-temperature service up to approximately 925°C (1,700°F).
- SAE 310S (UNS S31008): High-temperature grade with chromium-nickel composition optimized for thermal cycling and oxidation resistance at temperatures exceeding 1,100°C (2,012°F).
2.2 Key Mechanical Properties
- Tensile Strength: 515–750 MPa (varies by grade and heat treatment condition)
- Yield Strength: 205–310 MPa (0.2% offset)
- Elongation: ≥ 40% (at break, for annealed condition)
- Thermal Conductivity: 16–30 W/(m·K) (at 25°C)
- Coefficient of Thermal Expansion: 16–18 × 10⁻⁶ /°C (20–100°C)
- Maximum Service Temperature: 870–1,150°C (grade-dependent)
- Corrosion Resistance: Excellent against atmospheric, aqueous, and many chemical environments
2.3 Chemical Composition (Typical)
| Element | SAE 304 | SAE 316L | SAE 321 | SAE 310S |
|---|---|---|---|---|
| C (Carbon) | ≤ 0.08% | ≤ 0.03% | ≤ 0.08% | ≤ 0.08% |
| Cr (Chromium) | 18.0–20.0% | 16.0–18.0% | 18.0–20.0% | 24.0–26.0% |
| Ni (Nickel) | 8.0–10.5% | 10.0–14.0% | 9.0–12.0% | 19.0–22.0% |
| Mn (Manganese) | ≤ 2.0% | ≤ 2.0% | ≤ 2.0% | ≤ 2.0% |
| P (Phosphorus) | ≤ 0.045% | ≤ 0.045% | ≤ 0.045% | ≤ 0.045% |
| S (Sulfur) | ≤ 0.030% | ≤ 0.030% | ≤ 0.030% | ≤ 0.030% |
| Mo (Molybdenum) | — | 2.0–3.0% | — | — |
| Si (Silicon) | ≤ 1.0% | ≤ 1.0% | ≤ 1.0% | ≤ 1.5% |
| Ti (Titanium) | — | — | 5×(C–0.02)–0.70% | — |
3. Specifications
| Parameter | Specification |
|---|---|
| Product Name | Spiral Coil Tube / Coiltube (盘管) |
| Model / Reference No. | 1402 |
| Tube Type | Spiral wound coil tube (helical configuration) |
| Outer Diameter (OD) | Φ12 mm – Φ50 mm (customizable upon request) |
| Wall Thickness | 0.5 mm – 3.0 mm (tolerance: ±10%) |
| Coil Pitch | 15 mm – 60 mm (adjustable per furnace design) |
| Coil Diameter | Φ200 mm – Φ1,500 mm (determines furnace footprint) |
| Coil Length (Developed) | 5 m – 200 m (per assembly unit) |
| Surface Finish | Mirror polished (Ra ≤ 0.4 μm), matte (Ra ≤ 1.6 μm), or 2B finish |
| End Condition | Plain ends, beveled, or with welded fittings (flange, socket, threaded) |
| Heat Treatment | Solution annealed (1050–1150°C followed by rapid quench) |
| Operating Pressure | Up to 4.0 MPa (600 psi) — design-dependent |
| Operating Temperature Range | −196°C to +1,150°C (grade-dependent) |
| Applicable Standards | ASTM A213, ASTM A269, ASME SB167, GB/T 12771, EN 10217-7 |
| Packaging | Wooden crate or steel drum; desiccant-sealed; protective end caps |
4. Manufacturing Process
The production of Model No. 1402 Spiral Coil Tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a meticulously controlled multi-stage process to ensure dimensional accuracy, metallurgical integrity, and long-term service reliability.
4.1 Process Flow
- Raw Material Procurement: High-purity stainless steel strip or seamless tube stock is sourced from certified mills, with full material traceability documentation (Mill Test Certificate — MTC) provided for every batch.
- Dimensional Cutting & Preparation: Raw stock is precision-cut to the required developed length. Surface contaminants, scale, and oxides are removed through mechanical or chemical cleaning.
- Forming & Coiling: The tube is fed through a precision spiral coiling machine equipped with programmable tooling. The coil geometry (pitch, diameter, number of turns) is controlled by CNC-driven systems to maintain ±0.5 mm dimensional tolerance throughout the assembly.
- Welding (if applicable): For coil tubes fabricated from strip, longitudinal or spiral seams are welded using Tungsten Inert Gas (TIG) welding (GTAW — Gas Tungsten Arc Welding) under shielded argon atmosphere to prevent oxidation. Weld quality is verified via visual inspection and, where required, radiographic testing (RT).
- Heat Treatment: Completed coil assemblies undergo solution annealing in a continuous or batch furnace at 1050–1150°C, followed by controlled cooling (air or water quench) to restore full austenitic structure, relieve residual stresses, and maximize corrosion resistance.
- Pickling & Passivation: Post-heat treatment, the coil is subjected to acid pickling (nitric-hydrofluoric acid blend) to remove thermal scale, followed by passivation treatment to establish a stable chromium oxide protective layer.
- Surface Finishing: Depending on the specified finish grade, the coil undergoes mechanical polishing, electrolytic polishing, or mechanical brushing to achieve the required surface roughness (Ra value).
- Quality Inspection & Testing: Comprehensive final inspection includes dimensional verification (OD, wall thickness, coil pitch), visual surface examination, pressure testing (hydrostatic or pneumatic), and metallurgical verification (spectroscopic chemical analysis, hardness testing, grain size assessment).
- Packaging & Dispatch: Inspected coil assemblies are cleaned, protected with anti-corrosion wrapping, and packaged in export-grade wooden crates or steel drums with desiccant packets to prevent moisture ingress during transit.
4.2 Key Process Parameters
- Coiling Tension Control: ±5% of nominal tension to prevent ovality and dimensional drift
- Welding Parameters: TIG welding at 80–180 A, travel speed 40–80 mm/min, pure argon shielding (99.99% purity), flow rate 15–20 L/min
- Annealing Cycle: Ramp rate ≤ 5°C/min, soak time 30–60 minutes at temperature, controlled cooling
- Hydrostatic Test Pressure: 1.5× maximum working pressure, held for minimum 5 minutes with no visible leakage or deformation
5. Applications
The Model No. 1402 Spiral Coil Tube is engineered for use in demanding industrial thermal systems, with primary applications including:
5.1 Spiral Coil Water Jacket Furnace Systems
This is the primary application domain. The coil tube functions as the heat transfer element within a water jacket furnace, where:
- Combustion gases flow through the furnace chamber, heating the coil tube walls
- Circulating water or steam within the coil absorbs thermal energy
- The heated working fluid is directed to downstream processes (steam generation, process heating, power generation)
5.2 Additional Applications
- Petrochemical Industry: Feed preheating coils, reboiler tubes, and heat exchanger elements in refining and chemical processing plants
- Power Generation: Auxiliary heating coils in boiler systems and waste heat recovery units
- Food & Beverage Processing: Sanitary-grade heating coils for pasteurization, sterilization, and process heating equipment
- Pharmaceutical Industry: Clean-room compatible heating elements for reactors and distillation systems
- Textile & Paper Manufacturing: Drying oven heating coils and thermal processing equipment
- Oil & Gas: Subsea heating coils for pipeline flow assurance and offshore platform heating systems
- Heat Recovery Steam Generators (HRSG): Integral coil assemblies in combined-cycle power plants
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring that every Model No. 1402 Spiral Coil Tube meets international standards and regulatory requirements.
6.1 Quality Management Systems
- ISO 9001:2015 — Quality Management Systems certification
- ISO 14001:2015 — Environmental Management Systems certification
- ISO 45001:2018 — Occupational Health and Safety Management Systems certification
6.2 Product Standards & Testing Compliance
- ASTM A213: Standard Specification for Seamless Ferritic, Austenitic, and Ferritic-Austenitic Stainless Steel Tubing for High Temperature Service
- ASTM A269: Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for Chemical and General Industrial Applications
- ASME SB167: Specification for Seamless and Welded Austenitic Stainless Steel Tube for High Temperature Service
- GB/T 12771: Chinese National Standard for Stainless Steel Tubes for General Purposes
- EN 10217-7: European Standard for Non-alloy and Heat Resistant Steel Tubes for Technical Purposes
- ASME BPV Code Section I: Compliance for pressure vessel and power boiler applications
6.3 Inspection & Testing Protocols
- Mechanical Testing: Tensile testing, hardness testing (Brinell/Vickers), impact testing (Charpy V-notch) per ASTM E8/E10
- Chemical Analysis: Optical Emission Spectroscopy (OES)