Stainless Steel Coil Tube (Coiltube) — Storage, Handling & Product Specification
Product Overview
The Stainless Steel Coil Tube (Coiltube) manufactured by Wenzhou Jixing Metal Materials Co., Ltd. is a precision-engineered product designed for industrial piping, fluid conveyance, structural support, and specialized manufacturing applications. Delivered in continuous coil form, the Coiltube offers significant advantages in material utilization, downstream processing efficiency, and logistics flexibility. As classified under the Installation & Maintenance category — specifically within Storage & Handling — the proper stacking methodology for this product is a critical determinant of product integrity, surface quality, and dimensional accuracy upon delivery.
Material & Properties
The Coiltube is fabricated from austenitic and/or ferritic stainless steel grades, selected to deliver superior corrosion resistance, mechanical strength, and formability. Key material properties include:
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, chemical media, and high-temperature oxidation, attributable to the protective chromium oxide passive layer (Cr₂O₃) on the tube surface.
- Mechanical Strength: High yield strength and tensile strength ensuring structural integrity under pressure and mechanical loading conditions.
- Formability: Suitable for cold bending, rolling, and expansion without cracking or excessive work hardening.
- Surface Finish: Available in mill finish, pickled, polished (2B, BA), or custom surface treatments to meet application-specific aesthetic and functional requirements.
Specifications
| Parameter | Specification / Requirement |
|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) |
| Item No. | 213 |
| Category | Installation & Maintenance → Storage & Handling → Stacking Method |
| Material Grade | 304, 304L, 316, 316L, 321, 310S, 430 (per customer specification) |
| Outer Diameter (OD) | 6.0 mm – 219.0 mm (custom sizes available) |
| Wall Thickness | 0.5 mm – 12.0 mm |
| Coil Length | Typically 5,000 mm – 12,000 mm per coil (adjustable) |
| Coil Weight | Up to 3,000 kg per coil (subject to dimensional configuration) |
| Surface Finish | Mill Finish, 2B, BA, Polished, Pickled & Passivated |
| Standard Compliance | ASTM A213 / A269, EN 10216-5, GB/T 12771, JIS G3459 |
| Storage Orientation | Horizontal placement only (vertical stacking prohibited) |
| Inter-Layer Separation | Mandatory use of wooden boards or foam padding between layers |
| Maximum Stack Height | As determined by coil dimensions and load-bearing capacity; typically limited to prevent deformation |
Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous multi-stage manufacturing sequence:
- Raw Material Selection: High-purity stainless steel coil or strip is sourced from certified mills, with strict chemical composition verification (e.g., Cr, Ni, Mo content per grade specification).
- Slitting & Leveling: The raw coil is slit to the required width and cold-rolled to achieve precise wall thickness tolerances.
- Forming & Welding: The flat strip is formed into a tubular cross-section via a roll-forming process, followed by automatic argon arc welding (TIG) or laser welding to create the longitudinal seam.
- Heat Treatment: Solution annealing (for austenitic grades) or stress-relief annealing (for ferritic grades) is performed to eliminate residual stresses and restore full corrosion resistance.
- Pickling & Passivation: The tube surface is chemically cleaned to remove mill scale, heat tint, and welding contaminants, followed by passivation to establish a uniform chromium oxide layer.
- Surface Treatment: Polishing or brushing is applied as required for the target surface finish grade.
- Dimensional Inspection: Automated optical and ultrasonic systems verify OD, wall thickness, straightness, and coil geometry.
- Coiling & Packaging: The finished tube is coiled onto a precision mandrel, wrapped with protective film, and packaged for shipment.
Applications
The Coiltube finds extensive application across a broad spectrum of industrial sectors:
- Petrochemical & Energy: Heat exchanger tubes, reactor piping, and process lines handling aggressive media.
- Food & Pharmaceutical: Hygienic piping systems requiring cleanability and biocompatibility (304L/316L grades).
- Automotive & Aerospace: Exhaust systems, fuel lines, structural components, and heat-resistant applications (321/310S grades).
- Construction & Architecture: Structural support, decorative railings, and building envelope systems.
- Medical Devices: Surgical instrument tubing and implant-grade components (316L).
- General Manufacturing: Raw material for downstream fabrication of fittings, flanges, brackets, and custom assemblies.
Storage & Handling — Critical Specification
The integrity of the Stainless Steel Coil Tube is highly sensitive to improper storage and handling practices. The following protocols are mandatory to prevent surface damage, dimensional distortion, and structural degradation:
3.1 Stacking Orientation
All Coiltube products must be stored in a horizontal orientation on the ground or on a dedicated storage rack. Vertical stacking, tipping, or leaning of coils is strictly prohibited. Vertical placement subjects the coil to asymmetric gravitational loading, which can cause:
- Permanent deformation of the coil cross-section (ovality distortion)
- Compaction and crushing of the inner layers, leading to inter-layer adhesion
- Uncontrolled stress concentration at the coil's contact point with the support surface
- Increased risk of the coil toppling, resulting in catastrophic product damage and safety hazards
3.2 Inter-Layer Separation
When stacking multiple coils vertically (layer upon layer), each layer must be separated by a wooden board, foam padding, or equivalent non-abrasive interlayer material. The interlayer serves the following critical functions:
- Dent Prevention: Distributes the load from the upper coil across a wider area, preventing localized pressure points that cause surface indentation.
- Scratch Protection: Eliminates direct metal-to-metal contact between coils, preventing abrasive wear and galling of the surface finish.
- Deformation Control: Maintains the circular cross-sectional geometry of each coil by providing uniform radial support.
- Corrosion Mitigation: Prevents crevice corrosion (differential aeration) that can occur at metal-to-metal contact points, particularly in humid or coastal environments.
3.3 Storage Environment Requirements
- Storage area must be dry, well-ventilated, and protected from direct rain, snow, and chemical contamination.
- Ambient temperature should be maintained between 5°C and 40°C to prevent condensation-induced surface staining.
- Coils must be stored away from carbon steel products to avoid cross-contamination and iron contamination (ferritic staining).
- The ground surface must be level, clean, and free of sharp objects, debris, or standing water.
3.4 Handling & Lifting Protocols
- Coils must be lifted using appropriate rigging equipment (chain slings, lifting beams, or C-clamps) designed for coil geometry.
- Slings must be padded to prevent damage to the protective wrapping and tube surface.
- Never drag or roll a coil on the ground; always use a forklift, crane, or coil cart for transport.
- During loading and unloading, ensure the coil is secured against lateral movement and vibration.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality assurance framework supported by internationally recognized certifications:
- ISO 9001:2015 — Quality Management System certification ensuring consistent product quality and process control.
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to sustainable manufacturing practices.
- ISO 45001:2018 — Occupational Health & Safety Management System certification.
- ASME (American Society of Mechanical Engineers) — Material certification for pressure vessel and piping applications where applicable.
- EN 10204 3.1 / 3.2 Certificates — Third-party material inspection and test certificates (MTC) provided with each shipment.
- Mill Test Reports (MTR) — Detailed chemical composition and mechanical property reports for every heat lot.
- NACE MR0175 / ISO 15156 — Compliance for sour service applications (where applicable, for specific grades).
- CE Marking — Conformity with European New Approach Directives for products sold into the European Economic Area.
Unique Selling Points
- Zero-Damage Guarantee: The rigorous horizontal stacking and inter-layer separation protocol ensures that every coil arrives at the customer's facility with pristine surface integrity and dimensional accuracy.
- Full Traceability: Every coil is traceable to its original mill heat number, enabling complete quality chain documentation from raw material to finished product.
- Custom Configuration: Flexible sizing, surface finish, and coil weight options tailored to specific customer requirements and downstream processing needs.
- Multi-Grade Portfolio: Comprehensive range of austenitic, ferritic, and duplex stainless steel grades covering virtually all industrial application scenarios.
- Expert Handling Guidance: Comprehensive storage and handling documentation provided with every order, supported by technical consultation services.
Note: Adherence to the specified horizontal stacking and inter-layer separation protocols is a condition of the product warranty. Failure to comply with these storage requirements may result in product damage that is not covered under the manufacturer's quality guarantee. Customers are advised to review and implement these protocols within their receiving and warehousing procedures.