Stainless Steel Coil Tube (Coiltube) — Product Technical Specification
Product Overview
The Stainless Steel Coil Tube (also referred to as Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd is a precision-engineered continuous length tubing product, supplied in coiled configuration for ease of transportation, storage, and downstream processing. This product is specifically designed for applications demanding high thermal efficiency, corrosion resistance, and structural integrity — most notably in Fan Coil Units (FCUs), heat exchangers, refrigeration systems, and HVAC (Heating, Ventilation, and Air Conditioning) installations.
Coil tubes offer significant advantages over straight-length tubing in terms of material utilization, reduced welding joints, and streamlined fabrication workflows. The continuous coiled form factor minimizes waste during cutting and forming operations, aligning with modern energy-saving design principles in industrial and commercial building systems.
Material Composition & Properties
Stainless steel coil tubes are fabricated from austenitic and/or duplex stainless steel grades, selected to meet rigorous performance requirements across diverse operating environments.
- Common Grades: SUS304, SUS316, SUS316L, SUS321, SUS310S, and duplex grades (e.g., 2205)
- Key Mechanical Properties: High tensile strength (typically ≥ 520 MPa for 304 grade), elongation ≥ 40%, and excellent fatigue resistance
- Corrosion Resistance: Superior resistance to oxidation, pitting, crevice corrosion, and intergranular corrosion, particularly in chloride-containing environments
- Thermal Conductivity: Suitable for efficient heat transfer applications in refrigeration and HVAC systems
- Temperature Range: Operational capability from cryogenic temperatures (−196°C / −321°F) to elevated temperatures up to 870°C (1,598°F) depending on grade
- Hygienic Surface: Passivated surface finish ensuring non-toxicity and compliance with food-grade and pharmaceutical standards
Technical Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) | — |
| Product Code | 934 | Internal Catalog |
| Outer Diameter (OD) | Φ3.0 mm – Φ50.8 mm (customizable) | ASTM A213 / GB/T 12771 |
| Wall Thickness | 0.3 mm – 3.0 mm (customizable) | ASTM A269 / GB/T 12771 |
| Coil Inner Diameter | 500 mm – 1,200 mm | Manufacturer Standard |
| Coil Length per Roll | 10 m – 500 m (configurable) | — |
| Surface Finish | Bright Annealed (BA), No.1 Pickled, Polished (Ra ≤ 0.8 μm) | ASTM A240 / GB/T 4237 |
| Tolerance (OD) | ±0.05 mm (precision grade); ±0.10 mm (standard grade) | ISO 1128 |
| Tolerance (Wall Thickness) | ±0.03 mm (precision grade); ±0.05 mm (standard grade) | ISO 1128 |
| Available Grades | SUS304, 304L, 316, 316L, 321, 310S, 2205 Duplex | ASTM / JIS / GB |
| End Condition | Plain ends, cut to length, or custom-formed | — |
| Delivery Form | Continuous coil on wooden pallet or steel drum | — |
| Test Standards | Hydrostatic test, dimensional inspection, surface inspection, spectral analysis | ASTM A213 / GB/T 12771 |
Manufacturing Process
The production of high-quality stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorously controlled multi-stage manufacturing process:
- Raw Material Sourcing & Inspection: Ingot-grade stainless steel from certified mills undergoes incoming spectral analysis (PMI — Positive Material Identification) to verify chemical composition compliance.
- Hot Rolling & Annealing: Billet stock is hot-rolled into seamless tube blanks, followed by solution annealing to relieve internal stresses and establish the desired austenitic microstructure.
- Precision Cold Drawing: The tube blanks are cold-drawn through precision dies to achieve tight dimensional tolerances (±0.05 mm), ensuring uniform wall thickness and smooth surface finish critical for heat transfer performance.
- Pickle & Passivation: The drawn tubes undergo acid pickling to remove oxide scale, followed by passivation treatment to form a protective chromium oxide layer, enhancing corrosion resistance.
- Coiling & Winding: The processed tubing is wound onto precision-controlled coils using automated winding systems that maintain consistent tension, preventing deformation, kinking, or surface damage.
- Quality Inspection & Testing: Each coil undergoes comprehensive inspection including hydrostatic pressure testing, dimensional verification using laser gauging, surface defect detection, and non-destructive testing (NDT) such as eddy current or ultrasonic inspection.
- Packaging & Protection: Coils are wrapped with protective film, moisture-absorbing desiccants, and secured on wooden pallets or enclosed in steel drums for safe transit.
Applications
Stainless steel coil tubes find extensive application across multiple industries, with particular emphasis on energy-efficient thermal management systems:
- HVAC & Fan Coil Units (FCUs): Primary application in the design and manufacturing of fan coil unit heat exchangers, where coil tubes serve as the core heat transfer medium. Their high thermal conductivity and corrosion resistance contribute to improved energy efficiency in commercial and residential air conditioning systems.
- Refrigeration Systems: Used in evaporators, condensers, and capillary tubes for industrial and domestic refrigeration equipment, where cryogenic temperature resistance and long-term reliability are paramount.
- Heat Exchangers & Radiators: Employed in plate-fin heat exchangers, brazed heat exchangers, and automotive radiators requiring compact design and efficient thermal exchange.
- Food & Beverage Processing: Compliant with FDA and EU 1935/2004 standards for sanitary tubing used in dairy, beverage, and pharmaceutical processing lines.
- Chemical & Petrochemical Industry: Resistant to aggressive chemical media, making them suitable for chemical transport lines, reactor cooling systems, and process heat exchangers.
- Marine & Offshore Applications: 316L grade coil tubes resist chloride-induced pitting in seawater environments, suitable for shipboard HVAC systems and offshore platform cooling circuits.
- Medical Equipment: Biocompatible, autoclavable tubing for medical gas delivery systems, dialysis machines, and sterilization equipment.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework ensuring that every coil tube product meets international standards:
- ISO 9001:2015 — Quality Management System certification ensuring consistent product quality and process control
- ISO 14001:2015 — Environmental Management System certification reflecting sustainable manufacturing practices
- CE Marking — Conformity with European health, safety, and environmental protection standards
- ASTM Compliance — Full compliance with ASTM A213 (seamless tubing), ASTM A269 (welded tubing), and ASTM A240 (plate/strip) specifications
- GB/T Standards — Compliance with Chinese national standards including GB/T 12771, GB/T 4237, and GB/T 24511
- JIS Compliance — Conformity with Japanese Industrial Standards (JIS G3459, JIS G3446) for export markets
- Third-Party Testing — Products available with independent laboratory test reports from accredited bodies (e.g., SGS, BV, TUV) covering chemical composition, mechanical properties, dimensional accuracy, and corrosion resistance
Unique Selling Points
- Superior Energy Efficiency: The precision-drawn uniformity of wall thickness and bore diameter ensures optimal fluid flow dynamics and maximized heat transfer coefficients, directly contributing to energy savings in fan coil unit and heat exchanger applications.
- Extended Service Life: Austenitic stainless steel grades provide exceptional resistance to corrosion and fatigue, significantly reducing maintenance intervals and total cost of ownership (TCO) over the system lifecycle.
- Customization Flexibility: Full customization of OD, wall thickness, coil diameter, coil length, surface finish, and material grade to meet specific engineering requirements.
- Continuous Length Advantage: The coiled delivery format eliminates the need for butt welding of straight pipe sections, reducing potential leak points and improving structural integrity of heat exchanger assemblies.
- Hygienic & Food-Grade Compliance: Passivated surface finish with Ra values as low as 0.4 μm meets the stringent requirements of food, beverage, and pharmaceutical industries.
- Environmental Sustainability: High recyclability of stainless steel (over 90% recyclable) combined with material utilization optimization in coil form reduces manufacturing waste and carbon footprint.
Note: All specifications are subject to verification against the applicable purchase order and technical agreement. Custom specifications beyond the standard range are available upon request and subject to engineering review and minimum order quantity (MOQ) requirements. Wenzhou Jixing Metal Materials Co., Ltd reserves the right to refine manufacturing processes and specifications without prior notice, provided that such changes do not adversely affect product performance or compliance with stated standards.