Stainless Steel Coil Tube (Coiltube) — Special Packaging Specification
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered product designed for a wide range of industrial, commercial, and export applications. As a coiled form of seamless or welded stainless steel tubing, this product offers superior flexibility in downstream processing, including cutting, bending, and forming operations. The coil configuration maximizes material utilization, minimizes waste, and facilitates high-throughput manufacturing workflows.
A critical aspect of the product's value proposition lies in its Special Packaging Requirements (特殊包装需求), which ensure the integrity, cleanliness, and corrosion resistance of the tubing throughout storage, inland transport, and international maritime shipping. For high-grade applications — particularly EP (Electroplated/Export-Grade) Tubes and Export Tubes — packaging costs can reach 5%–10% of the total tube value, underscoring the importance of protective measures in maintaining product quality and meeting stringent international buyer specifications.
Material & Properties
The stainless steel coil tube is typically fabricated from austenitic and duplex stainless steel grades, including but not limited to:
- AISI 304 / SUS304 — General-purpose austenitic grade with excellent corrosion resistance and formability.
- AISI 304L / SUS304L — Low-carbon variant suitable for welding applications without sensitization risk.
- AISI 316 / SUS316 — Enhanced chloride resistance due to molybdenum addition; ideal for chemical processing and marine environments.
- AISI 316L / SUS316L — Low-carbon version of 316, widely used in pharmaceutical and food-grade applications.
- AISI 321 / SUS321 — Titanium-stabilized grade resistant to intergranular corrosion at elevated temperatures.
- AISI 310S / SUS310S — High-temperature alloy grade for furnace components and heat treatment equipment.
Key material properties include:
- Tensile Strength (Ultimate Tensile Strength, UTS): 515–620 MPa (grade-dependent)
- Yield Strength: ≥ 205 MPa
- Elongation: ≥ 40% (at fracture)
- Surface Finish: BA (Bright Annealed), 2B (Cold Rolled), No. 4 Brushed, Mirror (8K), or Matte
- Wall Thickness Tolerance: ±10% (standard) or ±5% (precision grade)
Packaging Specification
The special packaging system is engineered to protect the stainless steel coil tube from mechanical damage, moisture ingress, and surface contamination. The multi-layer packaging architecture is detailed below:
| Layer / Component | Description | Function | Material Standard |
|---|---|---|---|
| Wooden Crate (木箱) | Heavy-duty, ISPM-15 heat-treated solid wood or plywood crates with steel banding reinforcement. | Structural protection against impact, stacking loads, and forklift handling during inland and port logistics. | ISPM-15 / IPPC compliant; moisture content ≤ 22% |
| Double-Layer Shrink Wrap (双层缠绕膜) | Two continuous layers of polyethylene (PE) shrink film applied via automated stretch-wrapping machinery around the coil core. | Barrier against dust, moisture, and atmospheric contaminants; prevents coil loosening during transit. | HDPE (High-Density Polyethylene); thickness ≥ 23 μm per layer |
| Clean Bag (洁净袋) | Anti-static, low-lint polypropylene or polyester bags individually wrapping each tube length or coil segment. | Protection of surface finish (especially mirror and BA finishes) against scratches, fingerprints, and particulate contamination. | Food-grade or pharmaceutical-grade polypropylene; particle count < 1,000 particles/m² |
| Vacuum Sealing (真空封装) | Vacuum-pumping of air from the sealed clean bag or inner packaging layer, creating a low-oxygen environment. | Prevention of oxidation, rust formation, and moisture-related corrosion during long-duration storage and ocean transit. | Residual oxygen concentration < 5% (vol.); seal integrity verified by leak testing |
Specifications
| Parameter | Specification Range |
|---|---|
| Outer Diameter (OD) | Φ 1.0 mm – Φ 304.8 mm (1/16" – 12") |
| Wall Thickness (WT) | 0.10 mm – 12.0 mm (0.004" – 0.472") |
| Coil Inner Diameter (ID) | Φ 100 mm – Φ 500 mm (standard); custom sizes available |
| Coil Outer Diameter (OD) | Φ 600 mm – Φ 1,200 mm |
| Coil Weight | 500 kg – 5,000 kg per coil (typical) |
| Tube Length (Cut Length) | 3 m, 6 m, or custom (up to 12 m) |
| Surface Finish | BA, 2B, No. 4, Mirror (8K), Matte |
| End Treatment | Plain, Beveled (45°), Threaded, or Cap-Plugged |
| Coil Orientation | Longitudinal coil (standard) or transverse coil |
| Packaging Cost Ratio | 5% – 10% of tube value (EP/Export grade) |
Manufacturing & Packaging Process
The production and packaging workflow follows a rigorous sequence to ensure product integrity:
- Raw Material Inspection: Incoming stainless steel coils are verified for chemical composition (via Spark Optical Emission Spectroscopy, OES) and mechanical properties per ASTM A213 / ASTM A312 / EN 10216-5 standards.
- Pipe Milling & Forming: The coil is fed through a roll-forming or welding line to produce the desired tube OD and WT. Seamless tubes are drawn from pre-formed billets; welded tubes undergo TIG (Tungsten Inert Gas) welding with argon shielding.
- Heat Treatment & Annealing: Tubes undergo solution annealing (1050°C–1150°C) followed by controlled cooling to achieve the required grain structure and corrosion resistance.
- Surface Finishing: Mechanical polishing, chemical pickling, and passivation (via nitric acid or citric acid solution) are applied to achieve the specified surface finish and remove oxide scale.
- Quality Control (QC) Inspection: Dimensional verification (OD, WT, straightness), hydrostatic pressure testing (per ASTM A269), and surface defect inspection (visual and eddy-current) are performed.
- Clean Bag Wrapping: Each qualified tube or coil is individually wrapped in a low-lint clean bag to protect the surface finish.
- Vacuum Sealing: The clean bag is sealed and evacuated to remove ambient oxygen and moisture, creating an inert microenvironment around the product.
- Double-Layer Shrink Wrapping: The vacuum-sealed unit is placed on a rotating platform and wrapped with two continuous layers of PE shrink film by an automated stretch-wrapper.
- Wooden Crate Assembly: The shrink-wrapped coil is placed inside a heat-treated wooden crate. Desiccant packs (silica gel, 500 g per crate) and VCI (Vapor Corrosion Inhibitor) papers are inserted between the film and crate walls.
- Final Labeling & Documentation: Each crate is marked with product identification, heat number, quantity, net/gross weight, handling instructions, and export documentation (Certificate of Origin, Mill Test Certificate, Packing List).
Applications
The stainless steel coil tube with special packaging is deployed across multiple high-demand sectors:
- Pharmaceutical Industry: Bioreactor tubing, clean-in-place (CIP) systems, and sterile processing lines (316L, mirror finish, vacuum-packaged).
- Food & Beverage Processing: Milk processing lines, brewery piping, and food-grade heat exchangers (304/316L, BA finish).
- Medical Devices: Surgical instrument tubing, endoscopy channels, and implant-grade components (316L VM (Vacuum Melting), ultra-clean packaging).
- Chemical Processing: Acid handling lines, distillation columns, and reactor internals (316/321, corrosion-resistant packaging).
- Automotive & Aerospace: Exhaust system tubing, fuel lines, and hydraulic components (304/321, high-temperature grade).
- Architectural & Decorative: Handrails, structural elements, and facade components (2B/No. 4 finish).
- Marine & Offshore: Seawater piping, ballast systems, and desalination plant tubing (316/2205 duplex, anti-corrosion packaging).
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system aligned with international standards:
- ISO 9001:2015 — Quality Management System certification for manufacturing and packaging processes.
- ISO 14001:2015 — Environmental Management System ensuring sustainable packaging practices.
- EN 10204 3.1 / 3.2 — Material Testing Certificate (MTC) issued by an independent third-party inspection body.
- ASTM A213 / A269 / A312 — Compliance with American Society for Testing and Materials (ASTM) standards for seamless and welded stainless steel tubes.
- EN 10216-5 — European standard for welded stainless steel tubes for general purposes.
- JIS G3459 / G3460 — Japanese Industrial Standards for seamless and welded stainless steel tubes.
- NSF/ANSI 61 — Drinking water system component certification (for food-grade applications).
- ASME BPE — Bioprocessing Equipment standard compliance (for pharmaceutical tubing).
- CE Marking — Conformity with European Union health, safety, and environmental protection standards.
- ISPM-15 / IPPC — International Plant Protection Convention certification for heat-treated wooden packaging.
Unique Selling Points
- Multi-Layer Protective Architecture: The four-tier packaging system (clean bag → vacuum seal → double-layer shrink wrap → wooden crate) provides unmatched protection for high-value and surface-sensitive stainless steel coil tubes, particularly for export shipments spanning 30–45 day ocean transit routes.
- Cost-Effective Packaging Investment: While EP/export-grade packaging costs 5%–10% of tube value, this investment eliminates costly rework, rejects, and customer claims that can exceed 20% of shipment value in unprotected packaging scenarios.
- Customizable Packaging Solutions: Wenzhou Jixing offers tailored packaging configurations based on destination climate, transit duration, surface finish requirements, and end-user industry specifications.
- Full Traceability: Each coil is serialized with a unique heat number and accompanied by a comprehensive Mill Test Certificate (MTC), enabling full material traceability from raw steel to final installation.
- International Logistics Compliance: All packaging materials comply with ISPM-15, IATA (International Air Transport Association), and IMO (International Maritime Organization) regulations for seamless customs clearance and freight handling worldwide.
Ordering & Technical Support
Customers requiring special packaging for stainless steel coil tubes should specify the following at the time of inquiry:
- Grade, OD, WT, surface finish, and coil dimensions
- Destination country/port and transit mode (ocean, air, or rail)
- End-use application and industry-specific surface cleanliness requirements
- Required certifications (MTC, CE, NSF, ASME BPE, etc.)
- Custom labeling, branding, or documentation requirements
Note: Packaging costs are quoted separately from the base tube price. For EP-grade and export-grade orders, a packaging surcharge of 5%–10% of the tube value shall be applied. All packaging materials are sourced from certified suppliers and are subject to incoming inspection prior to assembly.