Large-Diameter Stainless Steel Coil Tube — Extra-Long Spool Configuration (ID ≥ 1000 mm / OD ≤ 2000 mm)
Product Overview
The Large-Diameter Stainless Steel Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd., represents the premium segment of coiled stainless steel tubing engineered specifically for extra-long length delivery. Unlike standard coil tubes that are wound on smaller spools, this product is formed onto large-diameter reels with an internal diameter (ID) of 1000 mm or greater and an external diameter (OD) not exceeding 2000 mm. This configuration enables continuous lengths of tubing far exceeding those achievable with conventional coil packaging, making it the solution of choice for applications demanding minimal joints, reduced installation time, and superior flow continuity.
The large-coil format is a specialized product category within the coil tube family. The increased spool dimensions provide greater arc length per revolution, which translates directly into smoother payout, reduced bending stress on the tube, and the ability to supply significantly longer continuous runs — often spanning multiple kilometers from a single spool. This makes the product uniquely suited for high-throughput processing lines, heat exchanger manufacturing, and continuous-forming applications where tube integrity and dimensional consistency are paramount.
Material & Properties
Wenzhou Jixing Metal Materials Co., Ltd. supplies large-diameter coil tubes in a comprehensive range of austenitic, ferritic, and duplex stainless steel grades, each selected to meet the specific mechanical, chemical, and thermal requirements of the end application.
- Common Austenitic Grades: 304 (UNS S30400), 304L (UNS S30403), 316 (UNS S31600), 316L (UNS S31603), 321 (UNS S32100), 310S (UNS S31008)
- Ferritic Grades: 430 (UNS S43000), 439 (UNS S43900)
- Duplex Grades: 2205 (UNS S32205), 2507 (UNS S32750)
- Key Mechanical Properties: Tensile strength ranging from 520 MPa (75,400 psi) for 304L to over 620 MPa (89,900 psi) for cold-worked 304; elongation typically ≥ 40% for annealed condition
- Corrosion Resistance: Excellent resistance to atmospheric, chemical, and aqueous environments; 316L and duplex grades offer superior chloride pitting and crevice corrosion resistance
- Temperature Capability: Continuous service from cryogenic temperatures (−196 °C / −321 °F) up to 870 °C (1,598 °F) depending on grade
- Surface Finishes: 2B, BA (Bright Annealed), No. 4 Brushed, Mirror (8K), and custom finishes available
Specifications
| Parameter | Specification | Notes |
|---|---|---|
| Product Category | Large-Diameter Coil Tube (Coiltube) | Extra-long length spool configuration |
| Coil Internal Diameter (ID) | ≥ 1000 mm (≥ 39.4 in) | Large spool format for maximum payout length |
| Coil External Diameter (OD) | ≤ 2000 mm (≤ 78.7 in) | Compatible with standard heavy-duty coil handling |
| Tube Outer Diameter | 3.0 mm – 150 mm (0.12 in – 5.9 in) | Custom sizes available upon request |
| Tube Wall Thickness | 0.1 mm – 8.0 mm (0.004 in – 0.315 in) | Tolerance: ±10% or ±0.05 mm, whichever is greater |
| Coil Weight (Typical) | Up to 5,000 kg (11,023 lb) | Dependent on tube size and grade |
| Continuous Length per Spool | Up to 2,000 m (6,562 ft) | Significantly exceeds standard coil configurations |
| Standards Compliance | ASTM A554 / A554M, ASTM A269 / A269M, EN 10217, GB/T 12771 | Multi-standard certification |
| End Condition | Plain, Beveled, or Threaded | Custom end preparation available |
| Packaging | Heavy-duty wooden or steel cradle with moisture barrier | Export-grade packaging |
Manufacturing Process
The production of large-diameter stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous, multi-stage process designed to ensure dimensional precision, metallurgical integrity, and surface quality at every step.
- Raw Material Selection & Inspection: High-purity stainless steel slabs or billets are sourced from certified mills. Incoming material undergoes spectroscopic analysis (OES) to verify chemical composition, along with visual and ultrasonic inspection to detect internal defects.
- Hot Rolling & Annealing: Steel is hot-rolled into flat strip or formed directly into round/rectangular profiles. Intermediate annealing cycles are performed to relieve residual stresses and restore ductility.
- Pipe Forming & Welding: The strip is precisely formed around a mandrel into a tube shape. For welded coil tubes, a high-frequency induction welding (HFW) or gas tungsten arc welding (GTAW/TIG) process is applied. Seamless coil tubes are produced via the piercing and cold-drawing route.
- Heat Treatment (Solution Annealing): Tubes are solution-annealed at temperatures between 1010 °C and 1150 °C (1,850 °F – 2,094 °F), followed by controlled cooling, to achieve the desired microstructure and maximize corrosion resistance.
- Cold Working & Sizing: Cold-drawing or cold-rolling reduces the tube to final dimensions with tight tolerances. This step also imparts desirable mechanical properties through strain hardening where required.
- Surface Finishing: Pickling and passivation remove scale and contamination. Additional finishing operations — bright annealing, polishing, or brushing — are performed to achieve the specified surface grade.
- Coiling onto Large Spool: The finished tube is wound onto a large-diameter coil with ID ≥ 1000 mm. This stage requires specialized payout and winding equipment capable of handling the increased spool weight and diameter. Precision tension control during winding ensures uniform coil layering and prevents tube distortion.
- Final Inspection & Quality Control: Every coil undergoes dimensional verification (OD, wall thickness, straightness), hydrostatic pressure testing, visual inspection, and non-destructive testing (eddy current, ultrasonic) as applicable. Chemical analysis and mechanical property testing are conducted on representative samples.
- Packaging & Shipping: Coils are secured on heavy-duty cradles with protective wrapping to prevent surface damage and moisture exposure during transit.
Applications
The large-diameter coil tube format is specifically engineered for applications where extra-long continuous lengths are critical, minimizing the number of joints, reducing labor costs, and improving system reliability. Key application areas include:
- Heat Exchangers & Boilers: Extra-long coil tubes enable the manufacturing of large heat exchanger bundles with fewer welds, improving thermal efficiency and reducing failure points. The continuous length is particularly advantageous for U-tube and hairpin heat exchanger designs.
- Automotive & Industrial Fuel Systems: Continuous-length stainless steel tubing for fuel lines, brake lines, and hydraulic circuits where leak-free, joint-minimized runs are essential for safety and durability.
- Food & Beverage Processing: Sanitary-grade coil tubes (316L, electropolished) for CIP (Clean-in-Place) systems, pasteurization lines, and fluid transfer in pharmaceutical and dairy processing where hygienic design and minimal crevice formation are mandatory.
- Oil & Gas Industry: Duplex and super-duplex coil tubes for subsea pipelines, wellhead instrumentation, and offshore platforms where high strength and chloride resistance are required in long continuous runs.
- Medical & Laboratory Equipment: Precision coil tubes for endoscope tubing, surgical instrument handles, and laboratory fluid delivery systems requiring biocompatibility and dimensional accuracy over extended lengths.
- Construction & Architectural: Large coils for decorative railings, structural bracing, and facade systems where long, unbroken runs provide both aesthetic continuity and structural integrity.
- Electronics & Telecommunications: Thin-wall coil tubes for heat pipes, vapor chambers, and cooling systems in high-performance computing and telecommunications infrastructure.
- Continuous-Forming Machinery: Coil tubes supplied on large spools feed directly into automated forming, cutting, and bending lines, enabling high-throughput production with minimal changeover time and material waste.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and holds the following certifications to ensure that every large-diameter coil tube meets or exceeds international standards:
- ISO 9001:2015 — Quality Management System certification demonstrating consistent capability to meet customer and regulatory requirements.
- ISO 14001:2015 — Environmental Management System certification reflecting responsible manufacturing practices and sustainable resource utilization.
- ISO 45001:2018 — Occupational Health and Safety Management System certification ensuring a safe production environment.
- EN 10204 3.1 Certification — Third-party verified material test certificates provided with every shipment, confirming compliance with specified standards.
- ASTM & ASME Compliance — Products manufactured in accordance with ASTM A554, ASTM A269, and applicable ASME codes for pressure-containing applications.
- GB/T Standards Compliance — Full adherence to Chinese national standards including GB/T 12771 (welded stainless steel tubes) and GB/T 14976 (seamless stainless steel tubes).
- Mill Test Reports (MTR) — Comprehensive documentation including chemical composition, mechanical properties, dimensional measurements, and NDT results supplied with each batch.
- Hydrostatic Testing — 100% hydrostatic pressure testing of all coil tubes to verify weld integrity and resistance to internal pressure.
- Non-Destructive Testing (NDT) — Eddy current testing (ECT) for weld inspection and ultrasonic testing (UT) for wall thickness verification performed on every production lot.
Unique Selling Points
Why Choose Wenzhou Jixing Metal Materials Co., Ltd. Large-Diameter Coil Tubes?
- Extra-Long Continuous Lengths: The large spool configuration (ID ≥ 1000 mm / OD ≤ 2000 mm) delivers continuous tube lengths up to 2,000 m per coil — dramatically reducing the number of joints, lowering installation labor costs, and improving overall system reliability compared to standard coil formats.
- Precision Dimensional Control: Advanced cold-working and sizing equipment ensures tight tolerances on OD, wall thickness, and straightness, even at extended lengths, enabling seamless integration into automated production lines.
- Specialized Handling Expertise: Wenzhou Jixing Metal Materials has purpose-built infrastructure and trained personnel for large-coil handling, including specialized payout equipment, heavy-duty cradles, and export-grade packaging that protects product integrity from mill to end-user.
- Comprehensive Grade Selection: From standard austenitic (304, 316L) to high-performance duplex (2205, 2507) grades, customers can source all required materials from a single, certified supplier — simplifying procurement and ensuring consistent quality.
- Customization Capability: Flexible manufacturing capacity allows for custom tube dimensions, surface finishes, end preparations, and coil configurations tailored to specific project requirements.
- Full Traceability & Documentation: Every coil is accompanied by complete EN 10204 3.1 certification and full mill test reports, providing complete material traceability from raw steel to finished product — essential for regulated industries such as pharmaceutical, food, and energy.
Technical Advisory Note
The large-diameter coil format (ID ≥ 1000 mm) is specifically designated for extra-long coil tube applications and requires specialized payout and handling equipment at the customer's facility. Standard coil uncoiling machinery may not accommodate the larger spool diameter and increased coil weight. Prospective buyers are advised to verify that their downstream processing equipment — including uncoilers, straighteners, and cutting stations — is compatible with the specified spool dimensions prior to ordering. Wenzhou Jixing Metal Materials Co., Ltd. provides technical consultation to assist customers in evaluating equipment compatibility and optimizing coil specifications for their specific production requirements.