Stainless Steel Coil Tube for Shell-and-Tube Glass Heat Exchangers
Product Overview
The Stainless Steel Coil Tube (盘管 / Coiltube), manufactured by Wenzhou Jixing Metal Materials Co., Ltd., is a precision-engineered tubular component designed for integration into shell-and-tube glass heat exchangers (列管式玻璃热交换器). These coil tubes serve as the primary heat transfer elements within the heat exchanger assembly, facilitating efficient thermal exchange between process fluids under demanding operating conditions. The product has successfully passed rigorous technical appraisal (技术鉴定), confirming its compliance with industry standards for performance, durability, and reliability in high-temperature and corrosive environments.
Wenzhou Jixing Metal Materials Co., Ltd. specializes in the production of high-grade stainless steel tubular products, with this coil tube product line representing a specialized offering for the glass heat exchanger segment. The coil tube design maximizes heat transfer surface area within a compact footprint, making it particularly advantageous for applications requiring high thermal efficiency in constrained installation spaces.
Material & Properties
The coil tubes are fabricated from premium-grade austenitic stainless steel, selected for its exceptional combination of corrosion resistance, thermal stability, and mechanical integrity. The material composition and performance characteristics are detailed below:
Material Grades
- 304 Stainless Steel (UNS S30400): The standard grade offering excellent general corrosion resistance, suitable for most industrial and chemical processing applications. Contains a minimum of 18% Chromium (Cr) and 8% Nickel (Ni).
- 316L Stainless Steel (UNS S31603): Enhanced grade with Molybdenum (Mo) addition (2–3%) for superior resistance to pitting and crevice corrosion, particularly in chloride-containing environments.
- 321 Stainless Steel (UNS S32100): Titanium-stabilized grade providing excellent resistance to intergranular corrosion at elevated temperatures, suitable for high-temperature heat exchanger applications.
Mechanical Properties
| Property | Specification | Test Standard |
|---|---|---|
| Tensile Strength (抗拉强度) | ≥ 520 MPa | ASTM A269 / GB/T 12771 |
| Yield Strength (屈服强度) | ≥ 205 MPa | ASTM A269 / GB/T 12771 |
| Elongation (延伸率) | ≥ 40% | ASTM A269 / GB/T 12771 |
| Hardness (硬度) | ≤ 220 HV | ASTM A262 |
| Thermal Conductivity (热导率) | 16.3 W/(m·K) at 100°C | ASTM E153 |
Chemical Composition (Typical — 316L Grade)
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.03 |
| Chromium (Cr) | 16.5 – 18.5 |
| Nickel (Ni) | 10.0 – 14.0 |
| Molybdenum (Mo) | 2.0 – 3.0 |
| Iron (Fe) | Balance |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.030 |
Specifications
| Parameter | Specification / Range | Notes |
|---|---|---|
| Product Designation (产品编号) | No. 1448 | Wenzhou Jixing Catalog |
| Outer Diameter (外径, OD) | 6.0 mm – 38.0 mm | Customizable per project requirements |
| Wall Thickness (壁厚) | 0.5 mm – 3.0 mm | Tolerance: ±0.1 mm |
| Coil Diameter (盘管外径) | 50 mm – 500 mm | Dependent on heat exchanger design |
| Tube Length (管长) | 1,000 mm – 6,000 mm (straight equivalent) | Coiled configuration |
| Surface Finish (表面光洁度) | 2B / BA / EP (Electropolished) | Ra ≤ 0.4 μm for EP finish |
| Operating Temperature (工作温度) | −196°C to +450°C | Continuous service range |
| Maximum Operating Pressure (最大工作压力) | ≤ 4.0 MPa (40 bar) | Dependent on OD and wall thickness |
| End Connection (端部连接) | Soldered / Brazed / Flanged | Compatible with glass heat exchanger ports |
| Coil Pitch (盘管间距) | 3.0 mm – 15.0 mm | Optimized for flow dynamics |
| Material Grade (材质) | 304 / 304L / 316 / 316L / 321 | Customer-selectable |
Manufacturing Process
The production of stainless steel coil tubes for glass heat exchangers follows a rigorous, multi-stage manufacturing process to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection (原材料选择): Only certified stainless steel strip or seamless tube stock from accredited mills is accepted. Incoming materials undergo spectroscopic analysis (光谱分析) to verify chemical composition and traceability.
- Cold Drawing / Forming (冷拉成型): The tube stock is cold-drawn to achieve precise outer diameter and wall thickness dimensions. This process enhances mechanical properties through work hardening while maintaining grain structure integrity.
- Coiling / Bending (盘绕成型): The drawn tube is precisely coiled using CNC-controlled bending equipment to achieve the specified coil diameter and pitch. The process is optimized to prevent kinking, ovality, or stress concentration at bend points.
- Solution Annealing (固溶退火): Coiled tubes undergo solution heat treatment at 1,050°C – 1,150°C followed by rapid quenching to restore full austenitic microstructure, eliminate residual stresses, and ensure maximum corrosion resistance.
- Pickling & Passivation (酸洗钝化): Surface contaminants, scale, and iron contamination are removed through controlled acid pickling. A passive chromium oxide layer is then formed to provide optimal corrosion protection.
- Surface Finishing (表面处理): For high-purity applications, electropolishing (电化学抛光) may be applied to achieve a Ra ≤ 0.4 μm surface finish, critical for hygienic and pharmaceutical applications.
- End Processing (端部加工): Tube ends are prepared with the appropriate connection type (solder cup, brazing sleeve, or flange) for integration into the glass heat exchanger manifold.
- Quality Inspection (质量检验): Each batch undergoes comprehensive inspection including dimensional verification, hydrostatic pressure testing (水压试验), visual inspection, and random destructive sampling for mechanical property confirmation.
Applications
The stainless steel coil tube for shell-and-tube glass heat exchangers finds extensive application across multiple industrial sectors:
- Chemical Processing (化工行业): Heat exchange in corrosive chemical environments where glass provides chemical inertness and stainless steel coil tubes provide mechanical strength and thermal conductivity. Applications include acid concentration, solvent recovery, and catalyst cooling systems.
- Pharmaceutical Manufacturing (制药行业): GMP-compliant heat exchangers for pharmaceutical fluid heating/cooling, including CIP (Clean-in-Place) compatible designs with electropolished surfaces.
- Food & Beverage Industry (食品饮料行业): Pasteurization, sterilization, and thermal processing systems where both hygienic design and thermal efficiency are paramount.
- Semiconductor & Electronics (半导体与电子行业): Ultra-pure chemical delivery systems and process fluid temperature control in wafer fabrication facilities.
- Energy & Power Generation (能源与发电): Auxiliary heat exchange systems in power plants, including cooling loops and thermal recovery applications.
- Environmental Engineering (环保工程): Waste heat recovery systems and flue gas treatment heat exchangers operating in aggressive atmospheric conditions.
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and certifications to ensure product conformity and customer confidence:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ISO 45001:2018 — Occupational Health and Safety Management System
- CE Marking — European Conformity for pressure equipment and industrial components
- Pressure Vessel & Heat Exchanger Standards: Compliance with GB/T 151 (Heat Exchangers), ASME PTC-12 (Performance Test Code), and EN 13445
- Material Standards: ASTM A269/A269M, GB/T 12771, EN 10216-5
- Technical Appraisal (技术鉴定): The coil tube and shell-and-tube glass heat exchanger system has passed formal technical appraisal, validating design integrity, manufacturing capability, and performance reliability under independent expert review.
Unique Selling Points
- Proven Technical Appraisal: The product line has undergone and passed formal technical appraisal (技术鉴定), demonstrating validated performance in real-world operating conditions.
- Hybrid Material Advantage: Combines the chemical inertness of borosilicate glass with the mechanical strength and thermal conductivity of austenitic stainless steel, providing an optimal solution for corrosive heat exchange applications.
- Customizable Design: Flexible manufacturing capability allows customization of coil geometry, tube dimensions, and material grades to match specific heat exchanger designs and process requirements.
- Full Traceability: Each production batch maintains complete material traceability from mill certificate through final inspection, ensuring quality assurance throughout the supply chain.
- Extended Service Life: The combination of proper material selection, controlled manufacturing processes, and solution annealing ensures extended operational life even in aggressive chemical environments.