Medium-Length Stainless Steel Coil Tube (100m – 500m/Coil)
Product Overview
The Medium-Length Stainless Steel Coil Tube (中长盘, Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd represents a precision-engineered continuous tubular product supplied in coiled form with lengths ranging from 100 meters to 500 meters per coil. This product category occupies a critical niche in the stainless steel tube supply chain, bridging the gap between short random-length coils and ultra-long seamless tube configurations. The medium-length coil designation provides optimal logistics efficiency, storage compactness, and downstream fabrication versatility for industrial applications demanding uninterrupted tube runs without weld joints.
As a core product within the company's Product Specifications (产品规格) and Geometric Parameters (几何参数) classification system, the Medium-Length Coil Tube is specifically engineered to serve as the primary feedstock for industrial heat exchanger manufacturing and instrument piping systems, where consistent wall thickness, dimensional accuracy, and continuous length are paramount to functional reliability.
Material & Properties
Medium-length coil tubes are typically fabricated from austenitic stainless steel grades selected for their superior corrosion resistance, thermal stability, and mechanical integrity under demanding process conditions. The following materials are standard for this product line:
- ASTM A269 / ASME SA-269 Grade 304 (UNS S30400): General-purpose austenitic stainless steel offering excellent formability, weldability, and resistance to a wide range of corrosive environments. Carbon content ≤ 0.08% ensures resistance to intergranular corrosion.
- ASTM A269 / ASME SA-269 Grade 316 (UNS S31600): Molybdenum-enhanced austenitic grade providing superior resistance to pitting and crevice corrosion, particularly in chloride-containing environments and chemical processing applications.
- ASTM A269 / ASME SA-269 Grade 321 (UNS S32100): Titanium-stabilized austenitic grade suitable for elevated-temperature service up to 870°C, resistant to sensitization during welding.
- ASTM A269 / ASME SA-269 Grade 316L (UNS S31603): Low-carbon variant of 316 with enhanced weldability and resistance to sensitization, preferred for critical hygienic and pharmaceutical applications.
Key mechanical and physical properties for typical Grade 304/316 coil tube include:
- Tensile Strength (抗拉强度): ≥ 515 MPa (Grade 304), ≥ 515 MPa (Grade 316)
- Yield Strength (屈服强度): ≥ 205 MPa (Grade 304), ≥ 205 MPa (Grade 316)
- Elongation (延伸率): ≥ 40% (minimum, per ASTM A269)
- Density (密度): 8.0 g/cm³
- Thermal Conductivity (热导率): 16.3 W/(m·K) at 300 K (Grade 304)
- Maximum Service Temperature (最高使用温度): 870°C (Grade 304), 870°C (Grade 316)
Specifications
The following table summarizes the complete dimensional and performance specifications for the Medium-Length Stainless Steel Coil Tube product:
| Parameter (参数) | Specification (规格) | Standard / Tolerance (标准/公差) |
|---|---|---|
| Coil Length (盘管长度) | 100 m – 500 m per coil (每卷) | ± 5% of nominal length |
| Outer Diameter (外径, OD) | Φ 1.5 mm – Φ 50.8 mm (typical range) | ± 0.05 mm (precision grade) |
| Wall Thickness (壁厚, WT) | 0.1 mm – 3.0 mm | ± 10% of nominal thickness |
| Coil Inner Diameter (盘管内径) | 150 mm – 600 mm (configurable) | As per customer requirement |
| Coil Outer Diameter (盘管外径) | ≤ 1,200 mm (maximum) | As per packaging standard |
| Surface Finish (表面处理) | 2B, No. 1, Pickled & Polished, Mirror (BA) | Per ASTM A478 |
| End Condition (端部状态) | Cut ends, deburred, optionally capped | — |
| Applicable Standards (适用标准) | ASTM A269, ASME SA-269, EN 10216-5, GB/T 12771 | — |
| Heat Treatment (热处理) | Solution Annealed (固溶退火) | 1050°C – 1150°C, water quench |
| Test Methods (检验方法) | Hydrostatic, Eddy Current, Ultrasonic, Visual | Per ASTM E709, ASTM E309 |
Manufacturing Process
The production of medium-length stainless steel coil tubes follows a rigorous multi-stage manufacturing workflow designed to ensure dimensional precision, microstructural integrity, and surface quality throughout the entire coil length:
- Raw Material Preparation (原材料准备): Cold-rolled stainless steel strip (冷轧带钢) is sourced from certified mills, verified for chemical composition via optical emission spectroscopy (OES) and mechanical properties via tensile testing. Incoming strip must conform to ASTM A240 or equivalent specifications.
- Forming & Welding (成型与焊接): The flat strip is fed through a series of progressive forming rolls (成型辊) that gradually shape the material into a near-circular cross-section. A high-frequency induction welding (高频感应焊接) process or orbital TIG welding (轨道TIG焊接) joins the longitudinal seam with filler metal matching the base material grade.
- Pipe Milling & Sizing (管体铣削与定径): The welded tube passes through a pipe mill (管机) equipped with sizing rolls that precisely control outer diameter and wall thickness. Precision tooling ensures uniform dimensional tolerances along the entire 100–500 m coil length.
- Heat Treatment (热处理): Solution annealing (固溶退火) is performed at temperatures between 1050°C and 1150°C followed by controlled cooling (typically water quench) to achieve a fully austenitic microstructure, relieve residual stresses from cold working, and restore maximum corrosion resistance.
- Pickling & Passivation (酸洗钝化): The coil is pickled using a controlled acid bath (typically nitric-hydrofluoric acid mixture or citric acid solution) to remove oxide scale, followed by passivation treatment to form a protective chromium oxide film on the surface.
- Coiling & Packaging (盘卷与包装): The finished tube is coiled onto a precision coil former with controlled tension to prevent deformation. Each coil is wrapped in protective film, moisture barrier material, and secured with steel strapping for safe transportation and storage.
Applications
The medium-length coil tube (100 m – 500 m per coil) is specifically optimized for industrial applications that benefit from continuous, joint-free tube runs. The primary application domains include:
Industrial Heat Exchangers (工业换热器)
This is the primary target application for medium-length coil tubes. Heat exchanger manufacturers require long, continuous tube lengths to minimize the number of expansion joints and butt welds in the tube bundle. The 100–500 m coil length allows for efficient U-tube (U型管) and hairpin-bend (发夹弯) configurations in shell-and-tube heat exchangers (管壳式换热器), plate-fin heat exchangers (板翅式换热器), and air-cooled heat exchangers (空冷器). The reduced number of weld joints directly translates to improved thermal efficiency, lower pressure drop, and enhanced resistance to corrosion-induced failures at weld zones.
Instrument Piping Systems (仪表管路系统)
The second major application domain is instrument piping, where medium-length coils provide the ideal balance between coil compactness and run-length continuity. Applications include:
- Pressure and temperature instrumentation lines in oil & gas, petrochemical, and chemical processing plants
- Control valve pilot lines and safety instrumented system (SIS) impulse lines
- Analytical instrument sampling lines requiring leak-tight, corrosion-resistant continuous runs
- Pharmaceutical and bioprocess CIP/SIP lines (Clean-In-Place / Sterilize-In-Place) where sanitary-grade continuous tubing is mandatory
Additional Applications
- Automotive exhaust systems and turbocharger manifolds (汽车排气系统与涡轮增压器歧管)
- Food processing equipment heat transfer coils (食品加工设备传热盘管)
- Refrigeration and HVAC condenser/evaporator coils (制冷与暖通空调冷凝器/蒸发器盘管)
- Aerospace hydraulic and pneumatic lines (航空液压与气动管路)
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system and product certification framework to ensure full compliance with international standards:
- ISO 9001:2015: Quality Management System certification covering all manufacturing, inspection, and delivery processes
- ISO 14001:2015: Environmental Management System certification
- EN 10204 3.1 Certificates: Third-party material and product testing certificates issued by accredited inspection bodies (e.g., SGS, BV, TUV, Intertek) for each heat lot
- CE Marking: Conformity with European pressure equipment directives (PED 2014/68/EU) where applicable
- Material Test Reports (MTR / 材质证明书): Full chemical analysis (化学成分报告), mechanical test results (力学性能报告), and heat treatment records (热处理记录) provided with each shipment
- Non-Destructive Testing (NDT) Reports: Eddy current testing (涡流检测) and ultrasonic testing (超声波检测) reports confirming weld integrity and wall thickness uniformity along the full coil length
Unique Selling Points
The Medium-Length Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd delivers distinct competitive advantages in the industrial tube supply market:
- Optimal Length-to-Logistics Balance (最优长度与物流平衡): The 100–500 m coil length range eliminates the logistical challenges of ultra-long coils (handling difficulty, storage space requirements) while providing sufficient continuous length to minimize downstream welding operations. This represents the industry sweet spot for heat exchanger and instrument piping applications.
- Full-Length Dimensional Consistency (全长尺寸一致性): Advanced pipe mill technology and in-line monitoring ensure that outer diameter, wall thickness, and roundness tolerances remain within specification across the entire 100–500 m coil length, not merely at discrete sampling points.
- Customizable Coil Configuration (可定制盘卷配置): Flexible coil inner diameter, coil outer diameter, and surface finish options allow customers to integrate the product seamlessly into their existing fabrication workflows and equipment.
- Multi-Grade Availability (多牌号可选): Comprehensive material grade selection from 304 through 316L, 321, and specialty alloys enables single-source procurement for diverse application requirements.
- End-to-End Traceability (端到端可追溯性): Every coil is linked to its heat number, mill certification, and full inspection history, satisfying stringent traceability requirements in aerospace, pharmaceutical, and nuclear-adjacent industries.
Technical Notes & Ordering Guidance
When specifying the Medium-Length Stainless Steel Coil Tube, customers should provide the following information to ensure optimal product selection:
- Required outer diameter and wall thickness (with applicable tolerance class)
- Material grade and applicable standard (ASTM, ASME, EN, or GB)
- Preferred coil length (within the 100–500 m range)
- Surface finish requirement (2B, BA, pickled, or custom)
- Required coil inner and outer diameters for handling equipment compatibility
- Special inspection requirements (NDT methods, third-party certification)
Wenzhou Jixing Metal Materials Co., Ltd provides technical consultation and sample testing support to assist customers in selecting the optimal product configuration for their specific application requirements.