Stainless Steel Coil Tube (盘管) — Product Technical Specification
Product Overview
The Stainless Steel Coil Tube (Coil Tube, 盘管) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is produced in continuous coiled form, offering superior flexibility in installation and fabrication compared to straight-pipe alternatives. Coil tubes serve as critical heat exchange elements in HVAC (Heating, Ventilation, and Air Conditioning) systems, particularly in Fan Coil Units (FCU), where they facilitate efficient thermal transfer between refrigerants or hot water and ambient air.
Compliant with and informed by the national standard GB/T 19232-2003 (Fan Coil Units), this coil tube product is designed to meet rigorous performance requirements for thermal efficiency, structural integrity, and long-term corrosion resistance in demanding industrial and commercial environments.
Material & Properties
Coil tubes are fabricated from high-grade stainless steel alloys, selected for their exceptional balance of mechanical strength, corrosion resistance, and thermal conductivity. The primary material grades offered include:
- AISI 304 / SUS 304 (06Cr19Ni10) — General-purpose austenitic stainless steel with excellent corrosion resistance and formability; the industry standard for HVAC coil applications.
- AISI 316L (022Cr17Ni12Mo2) — Enhanced molybdenum content provides superior resistance to chloride-induced pitting corrosion, ideal for marine and chemical processing environments.
- AISI 321 (06Cr18Ni11Ti) — Titanium-stabilized grade offering improved resistance to intergranular corrosion at elevated temperatures.
- AISI 316Ti (022Cr17Ni12Mo2Ti) — Combines the corrosion resistance of 316L with enhanced mechanical strength and weldability.
Key Material Properties (Typical for AISI 304)
| Property | Value | Unit |
|---|---|---|
| Tensile Strength (抗拉强度) | ≥ 520 | MPa |
| Yield Strength (屈服强度) | ≥ 205 | MPa |
| Elongation (延伸率) | ≥ 40 | % |
| Thermal Conductivity (热导率, 20°C) | 16.3 | W/(m·K) |
| Operating Temperature Range (工作温度范围) | −196 to +870 | °C |
| Density (密度) | 8.00 | g/cm³ |
| Chromium Content (铬含量) | 18.0 – 20.0 | % |
| Nickel Content (镍含量) | 8.0 – 10.5 | % |
Specifications
| Parameter | Specification |
|---|---|
| Product Name (产品名称) | Stainless Steel Coil Tube (盘管) |
| Catalog No. (序号) | 1047 |
| Outer Diameter (外径) | 6.35 mm, 9.52 mm, 12.70 mm, 15.88 mm (custom sizes available) |
| Wall Thickness (壁厚) | 0.50 – 2.00 mm (tolerance ±0.10 mm) |
| Coil Inner Diameter (盘管内径) | 150 – 600 mm (customizable) |
| Coil Length (盘管长度) | 3 – 50 m per coil (continuous) |
| Surface Finish (表面光洁度) | 2B, BA (Bright Annealed), No. 4 Brushed |
| Manufacturing Standard (制造标准) | GB/T 19232-2003, ASTM A213/A269, EN 10217-7 |
| End Condition (端部状态) | Plain end, thread-formed, or flanged (as specified) |
| Heat Treatment (热处理) | Solution Annealed (固溶处理) |
| Packing (包装) | Wooden pallet with moisture-proof wrapping |
Manufacturing Process
The production of stainless steel coil tubes follows a rigorous, multi-stage manufacturing process to ensure dimensional accuracy, metallurgical homogeneity, and surface quality:
- Hot Rolling (热轧) — Stainless steel slabs are hot-rolled into seamless tube blanks (管坯), establishing initial cross-sectional geometry and eliminating internal defects through plastic deformation.
- Heat Treatment & Pickling (热处理与酸洗) — The rolled blanks undergo solution annealing at 1050–1150°C followed by rapid water quenching to achieve a uniform austenitic microstructure. Subsequent acid pickling removes oxide scale, revealing a clean, passive surface.
- Piercing & Seamless Tube Forming (穿孔与无缝管成型) — Blanks are pierced and drawn through calibrated dies to produce seamless tubes with precise outer diameter and wall thickness tolerances.
- Pipe Coiling / Coil Winding (盘管成型) — The straight seamless tube is fed through a precision coiling station where controlled bending forces are applied to form a continuous helical coil. The bending process is carefully managed to prevent ovality, wrinkling, or work-hardening at the bend radius. The minimum bend radius is maintained at ≥ 2× the outer diameter to preserve structural integrity.
- Post-Coil Annealing (盘后退火) — Coiled tubes may undergo a controlled annealing cycle to relieve residual stresses introduced during the coiling process, restoring full mechanical properties.
- Surface Finishing (表面处理) — Depending on the application, coils receive additional surface treatment including electropolishing (电解抛光) for ultra-clean surfaces, passivation (钝化) to enhance corrosion resistance, or mechanical brushing for aesthetic purposes.
- Quality Inspection (质量检验) — Each coil undergoes comprehensive inspection including dimensional verification, visual examination, hydrostatic pressure testing (水压试验), and spectroscopic composition analysis.
Applications
The stainless steel coil tube finds extensive application across multiple industries, leveraging its corrosion resistance, thermal efficiency, and hygienic properties:
- HVAC Systems (暖通空调系统) — Primary application in Fan Coil Units (风机盘管机组) per GB/T 19232-2003; used as evaporator and condenser coils in commercial and industrial air conditioning systems.
- Heat Exchangers (换热器) — Spiral heat exchangers for plate-fin and shell-and-coil configurations in process industries.
- Food & Beverage Industry (食品饮料工业) — Hygienic-grade coils for pasteurization equipment, brewing systems, and CIP (Clean-In-Place) compatible thermal processing.
- Pharmaceutical Manufacturing (制药制造) — USP Class VI compliant coils for pharmaceutical reactors, sterilization loops, and cleanroom HVAC systems.
- Chemical Processing (化工处理) — Corrosion-resistant coils for chemical reactors, distillation columns, and acid processing systems (particularly 316L/316Ti grades).
- Marine & Offshore (海洋与海上工程) — Seawater-cooled heat exchanger coils and marine HVAC systems requiring high chloride resistance.
- Refrigeration & Cryogenics (制冷与低温工程) — Refrigerant coils for cold storage, refrigerated transport, and low-temperature process applications.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework to ensure product excellence and regulatory compliance:
- ISO 9001:2015 — Quality Management System certification ensuring consistent production quality and continuous improvement.
- GB/T 19232-2003 — National standard for Fan Coil Units; coil tubes are designed and tested to meet thermal performance and structural requirements specified therein.
- ASTM A213 — Standard specification for seamless austenitic stainless steel tubes, pipes, and heat-exchanger components.
- ASTM A269 — Standard specification for seamless and welded austenitic stainless steel tubing for chemical and heat-exchange equipment.
- EN 10217-7 — European standard for heat-resistant seamless steel tubes, austenitic and ferritic-austenitic steels.
- CE Marking — Conformity with European directives for market access in the European Economic Area.
- Mill Test Certificates (MTC) — Each shipment is accompanied by EN 10204 3.1 or 3.2 type material test certificates verifying chemical composition, mechanical properties, and dimensional compliance.
Unique Selling Points
1. Precision Coiling Technology: Advanced CNC-controlled coiling stations ensure consistent bend radii, minimal ovality (< 2%), and uniform coil geometry, reducing field installation time and improving heat transfer efficiency.
2. Full Material Traceability: Every coil is traceable to its heat number and production batch, enabling complete supply chain accountability from raw material to finished product.
3. Custom Engineering Capability: Flexible customization of diameter, wall thickness, coil pitch, coil diameter, and surface finish to meet specific OEM and project requirements.
4. Extended Service Life: The passive chromium oxide layer formed on stainless steel surfaces provides inherent self-healing corrosion protection, significantly reducing maintenance costs and replacement frequency compared to carbon steel alternatives.
5. Hygienic & Food-Safe Design: Available in electropolished and passivated finishes suitable for FDA, 3-A Sanitary, and EHEDG compliance in food, beverage, and pharmaceutical applications.
Conclusion
The Stainless Steel Coil Tube (Product No. 1047) from Wenzhou Jixing Metal Materials Co., Ltd represents a premium-grade heat exchange component engineered to the highest international standards. Its combination of superior corrosion resistance, precise dimensional control, and versatile application range makes it an indispensable solution for HVAC, industrial process, and hygienic thermal systems worldwide. The product's compliance with GB/T 19232-2003 and international equivalent standards underscores its reliability in critical thermal management applications.