Stainless Steel Coil Tube for Tubular Heating Furnace Applications
Product Overview
The Stainless Steel Coil Tube (Coiltube), manufactured by Wenzhou Jixing Metal Materials Co., Ltd, is a specialized heat-transfer tube product engineered for use in tubular heating furnaces (Tube Furnaces) and industrial process heating systems. This product is designed to maximize thermal efficiency, structural integrity, and material utilization rates within high-temperature radiant and convective heating environments. The coil tube configuration allows for compact installation while providing extensive heat-transfer surface area, making it an optimal choice for energy-intensive industrial applications.
This product line addresses a critical industry challenge: improving the utilization rate of coil tube materials in tubular heating furnaces (Convective Coil Tubes), thereby reducing material waste, lowering production costs, and extending service life under demanding thermal cycling conditions.
Material & Properties
The coil tubes are fabricated from premium-grade austenitic and austenitic-ferritic stainless steels, selected for their exceptional resistance to oxidation, thermal fatigue, and scaling at elevated operating temperatures. The primary material grades include:
- SAE 304 / 304L (UNS S30400 / S30403) — General-purpose austenitic stainless steel with excellent corrosion resistance and formability
- SAE 316 / 316L (UNS S31600 / S31603) — Molybdenum-bearing grade offering superior resistance to pitting and crevice corrosion
- SAE 310 / 310S (UNS S31000 / S31008) — High-temperature grade suitable for prolonged service up to 1150°C (2094°F) with outstanding oxidation resistance
- SAE 321 / 321H (UNS S32100 / S32109) — Titanium-stabilized grade providing excellent resistance to intergranular corrosion and thermal stress cracking
- SAE 347 / 347H (UNS S34700 / S34709) — Niobium-stabilized grade for high-temperature structural applications
Key mechanical and physical properties include:
- Tensile Strength (Rm): ≥ 520 MPa (304), ≥ 515 MPa (310S), ≥ 550 MPa (321H)
- Yield Strength (Rp0.2): ≥ 205 MPa (304), ≥ 205 MPa (310S), ≥ 275 MPa (321H)
- Elongation (A): ≥ 35% (minimum)
- Thermal Conductivity: 16.3 W/(m·K) at 100°C (304), 21.5 W/(m·K) at 100°C (310S)
- Maximum Service Temperature: 870°C (304), 1150°C (310S), 980°C (321H)
- Surface Finish: No. 1 Pickled & Annealed, 2B, or custom polished finishes
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | Φ10 mm – Φ168 mm (custom sizes available) | ASTM A213 / GB/T 12771 |
| Wall Thickness | 0.5 mm – 8.0 mm | ASTM A213 / GB/T 12771 |
| Coil Diameter (Bundle) | Φ300 mm – Φ2000 mm (configurable) | Manufacturer Specification |
| Length per Coil | 5 m – 50 m (continuous coil) | Manufacturer Specification |
| Material Grades | 304, 304L, 316, 316L, 310S, 321H, 347H | ASTM A213 / ASME SA-213 |
| Surface Treatment | Pickled & Annealed, Passivated | ASTM A380 |
| Heat Treatment | Solution Annealed (1050°C – 1150°C), Water Quenched | ASTM A999 |
| Welding Method | TIG (GTAW) / Orbital Automatic Welding | ASME BPV Code Section IX |
| Coil Pitch | 5 mm – 30 mm (adjustable per application) | Manufacturer Specification |
| Operating Pressure | Up to 15 MPa (design-dependent) | ASME BPV Code Section I |
| Operating Temperature Range | –196°C to +1150°C (grade-dependent) | Material Specification |
| Tolerance on OD | ±0.05 mm to ±0.50 mm (per size range) | ASTM A213 / GB/T 12771 |
| Tolerance on Wall Thickness | ±10% of nominal | ASTM A213 |
Manufacturing Process
The production of high-quality stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous multi-stage manufacturing process designed to ensure dimensional accuracy, metallurgical homogeneity, and optimal thermal performance:
- Raw Material Selection & Incoming Inspection — Certified stainless steel hot-rolled coils are sourced from approved mills, subjected to spectrographic analysis (PMI — Positive Material Identification), and verified against mill test reports (MTR).
- Cold Drawing / Cold Forming — Tubes are cold-drawn or cold-formed to achieve precise outer diameter and wall thickness tolerances, improving grain structure and mechanical properties.
- Coil Winding & Pitch Adjustment — Straight tubes are precisely wound into coil configurations using CNC-controlled coil winding machines, with adjustable pitch to optimize heat-transfer area and fit within furnace dimensions.
- Welding (if segmented coils) — TIG (Tungsten Inert Gas) welding or orbital automatic welding is employed for joining tube segments, with 100% visual inspection and selective radiographic testing (RT) of weld joints.
- Solution Annealing & Pickling — Coils are solution-annealed at temperatures between 1050°C and 1150°C followed by water quenching to restore full austenitic structure and relieve residual stresses. Subsequent acid pickling removes scale and oxide layers.
- Passivation — Chemical passivation treatment enhances the chromium oxide passive layer, improving long-term corrosion resistance.
- Final Quality Inspection — Dimensional verification (OD, wall thickness, coil diameter, pitch), hydrostatic testing (per ASTM A213), eddy current testing (ECT) for wall thickness uniformity, and surface quality assessment.
Applications
The stainless steel coil tubes manufactured by Wenzhou Jixing Metal Materials Co., Ltd are designed for a broad spectrum of high-temperature industrial applications, with particular emphasis on tubular heating furnace systems:
- Tubular Heating Furnaces (Tube Furnaces) — Convective and radiant coil tubes in petroleum refining, chemical processing, and power generation furnaces
- Convective Section Coil Tubes — Heat recovery in furnace convection zones, designed for maximum material utilization rates and extended service intervals
- Industrial Boilers & Waste Heat Recovery — Steam generation and waste heat recovery systems
- Chemical Processing — Reactor cooling, heat exchangers, and process piping in petrochemical and pharmaceutical industries
- Food & Beverage Processing — Sterilization equipment, pasteurization systems, and sanitary heat exchangers
- Petrochemical Crude Oil Distillation — Overhead coils, fractionator coils, and transfer lines in atmospheric and vacuum distillation units
- Aerospace & Defense — High-temperature components and thermal management systems
- Power Generation — Supercritical and ultra-supercritical boiler systems, steam generator tubes
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains comprehensive quality management systems and certifications to ensure product reliability and international market compliance:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ISO 45001:2018 — Occupational Health & Safety Management System
- ASTM A213 / ASME SA-213 — Standard specification for seamless austenitic stainless steel tubes for high-temperature service
- GB/T 12771 — Chinese national standard for welded and seamless stainless steel tubes for general applications
- ASME BPV Code Section IX — Welding qualification compliance
- EN 10216-5 — European standard for austenitic stainless steel tubes
- JIS G3459 — Japanese Industrial Standard for stainless steel tubes
Unique Selling Points
Optimized Material Utilization — Drawing upon advanced engineering research on improving coil tube material utilization rates in tubular heating furnaces, this product line incorporates design and manufacturing optimizations that reduce material waste by up to 15%, delivering significant cost savings for end-users.
- Customizable Coil Configuration — Flexible coil diameter, pitch, and length options allow precise adaptation to specific furnace geometry and thermal design requirements, minimizing installation challenges and maximizing heat-transfer efficiency.
- Extended Service Life — Premium material selection and rigorous heat treatment protocols ensure resistance to thermal fatigue, oxidation, and scaling, reducing unplanned shutdowns and maintenance frequency.
- Full Traceability — Every coil tube batch is accompanied by a complete mill test report (MTR), heat number traceability, and third-party inspection documentation, ensuring full supply-chain transparency.
- Technical Consultation Support — Wenzhou Jixing Metal Materials Co., Ltd provides engineering support for coil tube system design, including thermal performance modeling, stress analysis, and material selection guidance tailored to specific operating conditions.
- Cost-Effective Solutions — By optimizing the coil tube design for maximum material utilization in furnace applications, customers achieve lower capital expenditure (CAPEX) and reduced operational expenditure (OPEX) over the asset lifecycle.
Technical Documentation & Support
Wenzhou Jixing Metal Materials Co., Ltd provides comprehensive technical documentation including material certificates, dimensional drawings, welding procedure specifications (WPS), and performance data sheets. The company's engineering team is available for on-site technical support, furnace coil tube system design consultation, and post-installation performance monitoring to ensure optimal operational outcomes for each customer application.