Stainless Steel Coil Tube for Heat Pump Systems
Product Overview
The Stainless Steel Coil Tube (Product No. 732) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered tubular product designed specifically for heat pump systems, particularly those employing step-by-step defrost technology. This coil tube serves as a critical heat exchange component, providing superior thermal conductivity, exceptional corrosion resistance, and long-term structural integrity under demanding operating conditions. The product is manufactured to meet the rigorous demands of modern HVAC (Heating, Ventilation, and Air Conditioning) and refrigeration systems where reliable defrost cycles are essential for maintaining peak energy efficiency.
Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, typically conforming to AISI 304 or AISI 316L grades, selected for their outstanding combination of mechanical strength, thermal performance, and resistance to corrosive environments encountered during heat pump operation. Key material properties include:
- Corrosion Resistance: Excellent resistance to oxidation, chlorides, and condensate corrosion commonly encountered in defrost cycles
- Thermal Conductivity: Optimized thermal transfer characteristics ensuring efficient heat exchange between refrigerant and ambient air
- Mechanical Strength: High tensile strength and fatigue resistance to withstand repeated thermal cycling and pressure differentials
- Cryogenic Performance: Maintains ductility and structural integrity at low operating temperatures typical in refrigeration applications
- Hygienic Surface: Smooth internal and external finish minimizing fouling and promoting efficient fluid dynamics
Specifications
| Parameter | Specification |
|---|---|
| Product Designation | Coil Tube (盘管) — Product No. 732 |
| Material Grade | AISI 304 / AISI 316L (ASTM A213/A269) |
| Outer Diameter (OD) | 6.0 mm – 12.7 mm (configurable) |
| Wall Thickness | 0.5 mm – 1.2 mm |
| Tube Length | Custom coil length, typically 5 m – 50 m per spool |
| Coil Diameter | 100 mm – 300 mm (adjustable per application) |
| Surface Finish | Electropolished / Mill finish (Ra ≤ 0.8 μm) |
| Operating Temperature Range | −196 °C to +870 °C |
| Maximum Working Pressure | Up to 2.5 MPa (design-dependent) |
| Defrost Cycle Compatibility | Step-by-step defrost (progressive cycle) systems |
| Manufacturing Standard | GB/T 14976 / ASTM A269 / EN 10216-5 |
Manufacturing Process
The production of the stainless steel coil tube follows a multi-stage precision manufacturing process to ensure dimensional accuracy, material homogeneity, and functional reliability:
- Raw Material Selection: Certified stainless steel wire rod or seamless tube stock is sourced from approved mills with full material traceability documentation.
- Coil Forming: The straight tube is cold-formed into the required coil geometry using precision CNC-controlled bending machinery, ensuring uniform curvature radius and minimal residual stress.
- Heat Treatment: Solution annealing is performed to relieve cold-work stresses, restore full austenitic microstructure, and ensure maximum corrosion resistance.
- Pickling & Passivation: Surface treatment removes oxide scale and forms a protective chromium oxide layer, enhancing corrosion resistance and surface cleanliness.
- Dimensional Inspection: Each coil undergoes verification of OD, wall thickness, coil diameter, and length using calibrated measurement instruments.
- Pressure Testing: Hydrostatic or pneumatic pressure testing confirms the integrity of the tube under simulated operating conditions.
- Final Packaging: Tubes are protected with moisture-absorbent packaging and labeled with full traceability information including heat number, grade, and test certificates.
Applications
The stainless steel coil tube is engineered for use in the following applications:
- Heat Pump Systems: Primary application in air-source, ground-source, and water-source heat pumps utilizing step-by-step defrost technology for enhanced efficiency
- Commercial Refrigeration: Evaporator and condenser coils in cold storage, supermarket display cases, and walk-in coolers
- Industrial Process Heating/Cooling: Heat exchangers in chemical processing, pharmaceutical manufacturing, and food and beverage production
- Domestic HVAC: Residential air conditioning and heating systems requiring reliable defrost functionality
- Marine & Offshore: Corrosion-resistant heat exchange components in saltwater environments
Unique Selling Points
- Step-by-Step Defrost Optimization: Specifically designed for progressive defrost cycles that gradually reduce frost buildup, minimizing energy consumption and maintaining continuous heat transfer efficiency
- Superior Durability: Extended service life compared to copper or aluminum alternatives in corrosive or high-humidity environments
- Full Traceability: Every coil tube is accompanied by mill test certificates (MTC) and product identification for complete supply chain accountability
- Custom Configurations: Flexible manufacturing capability to meet specific coil diameter, tube length, and dimensional requirements per customer specifications
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains comprehensive quality management systems ensuring product conformity with international standards:
- ISO 9001:2015 — Quality Management System certification
- CE Marking — Conformity with European health, safety, and environmental protection standards
- GB/T Standards Compliance — National standards for stainless steel seamless and welded tubes (GB/T 14976, GB/T 12771)
- Mill Test Certificate (MTC) — EN 10204 Type 3.1 certification for each batch
- Non-Destructive Testing (NDT) — Electromagnetic testing (ET) and visual inspection per ASTM E1444
Note: All specifications listed are representative values. Custom specifications are available upon request. Wenzhou Jixing Metal Materials Co., Ltd reserves the right to modify product parameters with prior notification to customers.