Horizontal Continuous Bright Annealed (BA) Stainless Steel Coil Tube
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Wenzhou Jixing Metal Materials Co., Ltd. offers premium-grade Bright Annealed (BA) stainless steel coil tubes produced through an advanced horizontal continuous BA furnace process. This manufacturing method represents the industry mainstream for conventional BA tube production, delivering exceptional surface quality, superior dimensional consistency, and outstanding cost efficiency at high-volume capacity.
Product Overview
The Bright Annealed (BA) stainless steel coil tube is a precision-engineered product designed to deliver a clean, oxide-free surface finish without the need for subsequent pickling or mechanical polishing. Produced via a horizontal continuous bright annealing furnace, these coil tubes maintain a uniform, passivated surface that meets the stringent requirements of demanding industrial applications including food processing, pharmaceutical equipment, and chemical handling systems.
The horizontal continuous BA furnace process represents the most widely adopted and technologically mature method for producing bright annealed stainless steel tubing. This approach enables continuous, high-throughput processing while maintaining tight control over temperature uniformity, cooling atmosphere purity, and mechanical properties throughout the entire coil length.
Unique Selling Points
- High Production Capacity: The horizontal continuous BA furnace design enables uninterrupted, high-volume production with minimal downtime, ensuring reliable supply for large-scale orders.
- Low Manufacturing Cost: Continuous processing eliminates the batch-to-batch variability and energy waste associated with intermittent furnace operations, delivering competitive pricing without compromising quality.
- Excellent Surface Consistency: Uniform temperature distribution along the horizontal furnace length ensures a homogeneous surface finish across the entire coil, eliminating banding, discoloration, or localized annealing defects.
- Industry-Standard Process: As the mainstream production method for conventional BA tubes, this process is well-documented, highly reproducible, and trusted by global OEMs and system integrators.
- Superior Surface Finish: The protective atmosphere annealing eliminates the need for post-annealing pickling or passivation treatments, preserving the metallurgical integrity of the surface.
Material & Properties
Available Grades
- Austenitic: 304, 304L, 316, 316L, 321, 347
- Super Austenitic: 904L, 2205 (Duplex), 2507 (Super Duplex)
- Custom Grades: Available upon request for specialized applications
Key Properties
- Surface Finish: Bright Annealed (BA) — smooth, oxide-free, reflective surface with Ra ≤ 0.4 μm typical
- Surface Condition: Passivated; no residual scale, discoloration, or oxidation
- Mechanical Properties: Annealed condition providing excellent ductility and formability
- Corrosion Resistance: Enhanced surface integrity with no micro-cracks or residual stress
- Hygienic Performance: Smooth surface minimizes bacterial adhesion and biofilm formation
Specifications
| Parameter | Specification |
|---|---|
| Product Form | Coil Tube (continuous coil length) |
| Outer Diameter (OD) | Φ3.0 mm – Φ50.8 mm (custom sizes available) |
| Wall Thickness | 0.3 mm – 3.0 mm |
| Coil Length | 50 m – 200 m per coil (configurable) |
| Surface Treatment | Bright Annealed (BA) — protective atmosphere continuous furnace |
| Annealing Temperature | 1010°C – 1150°C (grade-dependent) |
| Protective Atmosphere | Endothermic gas / cracked ammonia / high-purity nitrogen |
| Surface Roughness (Ra) | ≤ 0.4 μm (typical) |
| Dimensional Tolerance | ±0.05 mm OD / ±0.03 mm wall thickness |
| Delivery Condition | Annealed (soft), bright surface, ready for secondary processing |
| Coil Core Diameter | Φ76 mm / Φ152 mm (standard options) |
| Coil Outer Diameter | Φ500 mm – Φ1200 mm |
| Surface Appearance | No scale, no discoloration, no scratches, uniform luster |
Manufacturing Process
Process Flow
- Raw Material Preparation: Cold-rolled stainless steel strip is slit to precise width and coiled for tube forming.
- Tube Forming: The strip is formed into seamless or welded coil tube via roll-forming or induction welding, depending on the grade and specification.
- Horizontal Continuous BA Furnace Annealing: The coil tube passes through a horizontally oriented continuous furnace under a controlled protective atmosphere. The furnace maintains uniform temperature zones for preheating, soaking, and controlled cooling.
- Atmosphere Control: A reducing atmosphere (endothermic gas or cracked ammonia) prevents oxidation during the high-temperature annealing cycle, preserving a bright, oxide-free surface.
- Controlled Cooling: Post-annealing cooling is managed to prevent re-oxidation and minimize residual stresses, ensuring optimal mechanical properties.
- Coil Winding & Packaging: The annealed coil is wound onto standard cores, protected with anti-corrosion wrapping, and packaged for shipment.
- Quality Inspection: Each coil undergoes dimensional verification, surface inspection, and mechanical property testing prior to release.
Horizontal Continuous BA Furnace Advantages
- Continuous Operation: Unlike batch-type furnaces, the horizontal continuous design enables uninterrupted processing, maximizing throughput and minimizing energy consumption per unit length.
- Uniform Temperature Profile: The horizontal orientation ensures consistent heat transfer across the tube cross-section, eliminating the surface variation common in vertical or rotary furnace configurations.
- Scalability: The furnace can be configured to handle multiple coil diameters and wall thicknesses without significant downtime or reconfiguration.
- Atmosphere Efficiency: Continuous gas flow management reduces atmosphere consumption and ensures stable reducing conditions throughout the annealing cycle.
Applications
- Food & Beverage Processing: Hygienic-grade tubing for dairy, brewing, and food processing equipment where surface cleanliness and corrosion resistance are critical.
- Pharmaceutical Equipment: Precision tubing for bioreactors, CIP/SIP systems, and pharmaceutical fluid transfer lines requiring aseptic-grade surfaces.
- Chemical Processing: Corrosion-resistant tubing for chemical reactors, heat exchangers, and process piping in aggressive chemical environments.
- Medical Devices: High-purity tubing for medical gas systems, dialysis equipment, and surgical instrument manufacturing.
- Heat Exchangers: Coil tubing for shell-and-tube heat exchangers, condensers, and evaporators requiring uniform surface quality and thermal efficiency.
- Aerospace & Automotive: Precision tubing for hydraulic systems, fuel lines, and structural applications demanding consistent mechanical properties.
- Ornamental & Architectural: Bright surface finish suitable for visible structural and decorative applications.
Quality Certifications
- ISO 9001:2015 — Quality Management System Certification
- ISO 3834 — Welding Quality Management (where applicable)
- EN 10204 3.1 — Material Test Certificate
- ASTM A269 / A270 — Compliance with seamless and welded stainless steel tube standards
- EN 10217-7 — European standard for austenitic stainless steel tubes
- GB/T 12771 — Chinese national standard for austenitic stainless steel seamless tubes
- Food Safety Compliance: FDA 21 CFR compliant (available upon request)
- Mill Test Reports: Provided with every shipment, including chemical composition, mechanical properties, and surface inspection results
Ordering Information
Wenzhou Jixing Metal Materials Co., Ltd. supports both standard and custom specifications for horizontal continuous BA furnace-produced stainless steel coil tubes. Customers are encouraged to provide detailed specifications including grade, dimensions, surface requirements, and quantity for tailored quoting and production planning.
Why Choose Wenzhou Jixing? With state-of-the-art horizontal continuous BA furnace facilities, rigorous quality control protocols, and deep expertise in stainless steel coil tube manufacturing, Wenzhou Jixing delivers the reliability, consistency, and value that global industrial customers demand.