Stainless Steel Coil Tube — Storage & Handling Specifications

Product Overview

Stainless steel coil tubes manufactured by Wenzhou Jixing Metal Materials Co., Ltd. are supplied in continuous coiled form, optimized for downstream processing applications including bending, forming, and automated cutting operations. These coil tubes are designed for versatile use across industrial, chemical, food-grade, and construction sectors. A critical aspect of maintaining product integrity from factory to end user is adherence to strict storage and handling protocols, which directly impact surface finish quality, dimensional accuracy, and structural performance.

Material & Properties

• Base Material: Austenitic stainless steel grades (304, 304L, 316, 316L, 321, 310S) and duplex grades available upon request
• Form: Coiled tubing (continuous length wound into compact coils for efficient transport and storage)
• Surface Finish: Bright annealed (BA), pickled and passivated (2B), or custom finishes
• Key Properties: Excellent corrosion resistance, high strength-to-weight ratio, non-magnetic (austenitic grades), hygienic surface suitable for food and pharmaceutical applications
• Temperature Range: Operating temperatures from cryogenic (-196°C) up to 870°C depending on grade selection

Specifications

Parameter	Specification
Outer Diameter (OD)	3.0 mm – 168.0 mm
Wall Thickness	0.3 mm – 8.0 mm
Coil Length	Customizable (typically 100 m – 1000 m per coil)
Coil Inner Diameter	300 mm / 400 mm / 500 mm / 600 mm
Standard Tolerance (OD)	±0.05 mm (precision) / ±0.1 mm (standard)
Standard Tolerance (Wall)	±10% of nominal wall thickness
Applicable Standards	ASTM A213, ASTM A269, EN 10217, GB/T 12771, JIS G3459
Available Grades	304, 304L, 316, 316L, 321, 310S, 316Ti, Duplex 2205

Manufacturing Process

The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous multi-stage process:

1. Hot Rolling: Billet or slab is hot-rolled into seamless pipe or ERW/ welded strip depending on the intended product type.
2. Precision Cold Drawing / Pilgering: Tubes are cold-worked to achieve precise dimensional tolerances and enhanced mechanical properties.
3. Heat Treatment & Annealing: Tubes are annealed in a controlled atmosphere (bright annealing or solution annealing) to relieve stresses and restore corrosion resistance.
4. Pickling & Passivation: Surface scale removal and chromium oxide layer formation for maximum corrosion protection.
5. Non-Destructive Testing (NDT): Eddy current testing, ultrasonic testing, and hydrostatic testing to ensure wall integrity and absence of defects.
6. Coiling: Finished tubes are wound into coils of specified inner diameter with controlled tension to prevent deformation and surface damage.
7. Protective Packaging: Each coil is wrapped with protective film or VCI paper and secured with steel strapping before shipping.

Storage & Handling — Critical Requirements

Proper storage and handling is essential to preserve the quality, dimensional accuracy, and surface integrity of stainless steel coil tubes. The following protocols must be strictly observed at all stages — from warehouse storage to on-site installation:

Horizontal Placement — Mandatory

• Coil tubes must be stored horizontally on a level, stable surface (racking, pallets, or dedicated coil stands).
• Vertical stacking or upright placement is strictly prohibited. Storing coils in a vertical or inverted position subjects the outer layers to excessive compressive loads, which can cause permanent deformation, coil collapse, and inter-layer damage.
• The coil axis must remain parallel to the ground to distribute gravitational forces evenly across the coil structure.
• Storage surfaces must be clean, dry, and free of sharp edges, rust, or abrasive materials that could damage the protective wrapping or tube surfaces.

Inter-Layer Separation — Mandatory

• When stacking coils vertically (limited to 2 layers maximum in controlled environments), inter-layer separation materials must be used between each coil layer.
• Acceptable separation materials include:
  • Hardwood boards (minimum 25 mm thickness, smooth-surfaced, moisture-resistant)
  • High-density foam pads (minimum 30 mm thickness, closed-cell polyethylene or polyurethane)
• Separation materials must span the full width of the coil to prevent point-loading at the coil edges.
• The purpose of inter-layer separation is to prevent indentations, surface scratches, and coil deformation caused by direct coil-to-coil contact under stacking loads.

Additional Handling Precautions

• Use appropriate lifting equipment (chain slings, coil hooks, or C-clamps) — never use wire rope directly on coil surfaces.
• Protect tubes from contact with carbon steel to prevent iron contamination and subsequent rust staining.
• Store in a dry, well-ventilated area away from corrosive chemicals, chlorides, and salt spray.
• Ensure coils are adequately secured against wind or vibration during transport.
• Inspect protective wrapping before unloading; report any damage immediately.

Applications

• Heat Exchangers & Boilers: Coiled tubing provides seamless continuous lengths ideal for coil-wound heat exchangers, condensers, and evaporators.
• Chemical Processing: 316L and duplex coil tubes resist aggressive chemical environments in reactors, piping systems, and heat transfer equipment.
• Food & Beverage Industry: Hygienic-grade coil tubing for pasteurization systems, brewing equipment, and dairy processing lines.
• Automotive Industry: Exhaust systems, fuel lines, and turbocharger components requiring high-temperature resistance.
• Medical Devices: Surgical instrument tubing, implant-grade coils, and dialysis equipment components.
• Construction & Architecture: Structural applications, handrails, and decorative elements in coastal or corrosive environments.
• Energy Sector: Solar thermal collectors, geothermal systems, and nuclear-grade applications.

Quality Certifications & Compliance

• ISO 9001:2015 — Quality Management System certification ensuring consistent production quality and process control.
• ISO 14001 — Environmental Management System certification for sustainable manufacturing practices.
• EN 10204 Type 3.1 — Third-party inspection and material certification for each batch.
• ASTM / EN / GB Standard Compliance — Full dimensional, mechanical, and chemical property verification per applicable international standards.
• MILL TEST CERTIFICATES — Provided with every shipment, including chemical composition analysis, tensile test results, hardness testing, and NDT reports.
• Third-Party Inspection Available — SGS, BV, or client-designated inspectors may witness production, testing, and loading.

Key Selling Points

• Uncompromised Surface Quality: Strict adherence to horizontal storage and inter-layer separation protocols ensures zero indentations, scratches, or deformation — delivering factory-fresh surfaces to your production line.
• Dimensional Precision: Tight tolerances maintained from manufacturing through delivery, eliminating the need for costly rework or secondary machining.
• Grade Flexibility: Wide range of stainless steel grades available to match specific corrosion, temperature, and mechanical requirements.
• Custom Coil Configuration: Tailored coil dimensions, lengths, and packaging to optimize your uncoiling and processing workflow.
• Full Traceability: Complete documentation and material certification for every coil, supporting regulatory compliance in demanding industries.
• Expert Handling Guidance: Comprehensive storage and handling instructions provided with every order to maximize product life and performance.

Important Notice: Failure to follow the prescribed horizontal storage and inter-layer separation guidelines will result in voided surface quality warranties. Wenzhou Jixing Metal Materials Co., Ltd. accepts no liability for damage caused by improper storage, handling, or stacking practices at the buyer's facility.