Stainless Steel Coil Tube — Packaging, Handling & Transportation Specifications

Product Overview

The stainless steel coil tube (盘管, Coiltube) supplied by Wenzhou Jixing Metal Materials Co., Ltd. is a precision cold-drawn or cold-rolled seamless and welded tube product supplied in coiled form for downstream processing, forming, and fabrication applications. This technical specification addresses the critical risk control measures governing the packaging, handling, loading, and transportation of coil tube products to ensure zero damage from the point of factory dispatch to the end-user's receiving dock. The packaging and logistics protocol is classified under Commercial Procurement — Risk Prevention and Control — Transportation Damage, reflecting its role as a contractual safeguard against transit-related quality degradation.

Coil tube products, due to their elongated and wound geometry, are inherently vulnerable to surface marring, denting, edge deformation, and structural distortion during transport. This specification defines the mandatory packaging architecture, handling prohibitions, and acceptance criteria that mitigate these risks in accordance with international best practices and contractual obligations.

Material & Properties

Base Material

• Grade: 304, 304L, 316, 316L, 321, 310S, 904L, and custom alloy compositions conforming to ASTM A269, ASTM A213, ASTM A554, EN 10216-5, or GB/T 12771
• Microstructure: Fully annealed austenitic structure with uniform grain distribution
• Surface Finish: Bright annealed (BA), pickled and passivated (2B), or mirror polished (No. 4 / 8K) depending on application requirements
• Coil Dimensions: Outer diameter (OD) ranging from 50 mm to 250 mm; wall thickness from 0.3 mm to 3.0 mm; coil width from 10 mm to 60 mm; coil inner diameter (ID) typically 150 mm or 250 mm
• Coil Weight: Typically 200 kg to 1,500 kg per coil depending on dimensions and grade

Key Mechanical Properties

• Tensile Strength (R_m): ≥ 520 MPa (Grade 304), ≥ 515 MPa (Grade 316L)
• Yield Strength (R_p0.2): ≥ 205 MPa (Grade 304)
• Elongation (A₅₀): ≥ 40%
• Hardness: ≤ 95 HRB (annealed condition)

Specifications

Parameter	Specification / Requirement	Standard Reference
Packaging Type	Wooden crate (木箱) with internal partition boards (隔板) and external stretch film wrapping (缠绕膜)	ISO 4180 (Transport packaging)
Inner Partition	Hardboard or plywood dividers placed between coil layers or adjacent coils to prevent inter-coil contact and friction	Company internal specification
Outer Wrap	Industrial-grade PE stretch film (缠绕膜), minimum 20 μm thickness, fully wrapped with ≥ 90% overlap coverage	ISO 9705 (Stretch film)
Wooden Crate Material	Heat-treated hardwood or composite board; ISPM-15 compliant for international export	ISPM-15 / IPPC
Handling Prohibition	Throwing (抛掷) and rolling (滚落) are strictly prohibited under all circumstances	Contractual obligation
Lifting Method	Mechanical lifting only — fork lift with coil cradle or overhead crane with appropriate spreader beam	ISO 2321 (Lifting equipment)
Stacking Limit	Maximum 2 layers of packed crates; no stacking above rated load capacity	Company internal specification
Moisture Protection	Desiccant sachets (minimum 200 g per crate) and moisture barrier film required for shipments exceeding 30 days transit	ISO 11607 (Packaging)
Marking & Labeling	Each crate marked with product grade, heat number, coil ID, weight, dimensions, "This Side Up" arrow, and "Fragile — No Dropping" warning	ISO 780 (Marking)
Appearance Inspection Standard	As defined in purchase contract — visual inspection for scratches, dents, deformation, surface contamination, and dimensional deviation upon delivery	Contractual clause
Claim Period	Buyer must submit damage claims within 7–15 calendar days of receipt (as specified in contract)	Contractual clause

Manufacturing Process

Coil Tube Production Sequence

1. Raw Material Selection: Certified stainless steel bar stock or hot-rolled coil conforming to the specified grade chemistry
2. Piercing / Decapping: Hot piercing of bar stock or slitting of hot-rolled coil to produce tube blanks
3. Cold Drawing / Cold Rolling: Multi-pass cold forming through precision tooling to achieve target OD, wall thickness, and roundness tolerances
4. Solution Annealing: Continuous or batch annealing at 1,050–1,150 °C followed by controlled cooling to restore full austenitic microstructure
5. Pickling and Passivation: Immersion in mixed acid bath (HNO₃ + H₂SO₄) to remove oxide scale, followed by passivation treatment to establish protective chromium oxide film
6. Surface Polishing (Optional): Electrolytic polishing or mechanical polishing to achieve specified surface finish grade
7. Coiling: Precision winding onto mandrel to produce uniform coil with controlled tension to prevent springback and layer displacement
8. End Sealing: Coil ends secured with steel banding and plastic edge protectors to prevent unrolling and edge damage
9. Quality Inspection: Dimensional verification (OD, WT, length), surface inspection, hydrostatic testing, and chemical/spectroscopic analysis
10. Packaging: Application of protective inner wrap, placement in wooden crate with partition boards, external stretch film wrapping, and crate assembly

Applications

• Automotive Industry: Exhaust system tubing, fuel injection lines, turbocharger piping, and structural reinforcement tubing
• Food Processing Equipment: Hygienic transfer lines, CIP (Clean-In-Place) systems, and sanitary piping where coil tube is formed into elbows, tees, and custom geometries
• Medical Devices: Endoscope shafts, surgical instrument tubing, and implantable device components requiring high purity and surface integrity
• Chemical Processing: Reactor internals, heat exchanger tubes, and corrosion-resistant transfer lines
• Electronics Manufacturing: Precision tubing for heat sinks, enclosures, and connector housings
• Construction & Architecture: Decorative railings, structural bracing, and architectural feature elements
• Petroleum & Gas: Downhole tubing, wellhead connections, and subsea manifold components
• Aerospace: Hydraulic lines, fuel system tubing, and structural components requiring high strength-to-weight ratio

Quality Certifications

• ISO 9001:2015 — Quality Management System certification ensuring consistent manufacturing and packaging processes
• ISO 14001:2015 — Environmental Management System certification for sustainable packaging and waste management practices
• EN 10204 3.1 Certificate — Third-party material test certificate for each heat/lot of coil tube
• MTC (Mill Test Certificate) — Full chemical composition, mechanical property, and dimensional traceability documentation
• ISPM-15 Certification — Phytosanitary treatment marking on all wooden packaging for international export compliance
• CE Marking — Conformity with European directives for products intended for the European Economic Area
• NACE MR0175 / ISO 15156 — Compliance for sour service applications (applicable grades)
• ASME BPV Code — Boiler and Pressure Vessel Code compliance for pressure-containing applications

Unique Selling Points

• Contractual Risk Mitigation: Explicit contractual definition of appearance inspection standards and damage claim procedures provides both buyer and seller with clear accountability frameworks, reducing post-delivery disputes
• Multi-Layer Packaging Architecture: The combination of wooden crate structural protection, internal partition isolation, and external stretch film moisture/dust barrier provides comprehensive transit protection for high-value coil products
• Zero-Contact Handling Protocol: Strict prohibition of manual throwing and rolling ensures that the precision surface finish and dimensional tolerances achieved during manufacturing are preserved through the entire logistics chain
• Full Traceability: Each coil is individually identified with heat number, grade, and production date, enabling complete supply chain traceability from raw material to end application
• Export-Ready Compliance: ISPM-15 treated packaging with full documentation ensures seamless customs clearance and regulatory compliance for international shipments

Handling & Storage Requirements

Transportation Handling Rules

1. All coil tube shipments must be moved using mechanical equipment only — manual carrying of coils above 50 kg is prohibited
2. Fork lift operations must use coil-specific forks or cradle attachments; standard pallet forks are not acceptable for direct coil handling
3. Transport vehicles must be equipped with adequate load securing (chain, ratchet straps, or blocking) to prevent shifting during transit
4. Maximum transit acceleration/deceleration must not exceed 0.3 g lateral or 0.5 g vertical
5. Coil tubes must not be stored outdoors without additional weatherproofing for periods exceeding 48 hours

Storage Conditions

• Temperature: 5 °C to 40 °C
• Relative Humidity: ≤ 70% (condensation-free)
• Storage Duration: Recommended maximum 12 months in original packaging
• Segregation: Store away from carbon steel, acid sources, and chlorinated environments to prevent cross-contamination and crevice corrosion

Acceptance & Claim Procedure

Contractual Appearance Inspection Standard: Upon receipt of coil tube shipment, the buyer shall conduct a visual and dimensional inspection within 48 hours of delivery. Acceptance criteria include: (1) no visible dents, scratches, or surface marks exceeding 0.1 mm depth; (2) no coil layer displacement or deformation exceeding 2% of OD; (3) no packaging damage indicating impact or improper handling; (4) surface finish conforming to the grade specified in the purchase order. Any deviation from these criteria must be documented with photographs and submitted as a formal claim within the contractual claim period (typically 7–15 calendar days). Claims must include: original packing list, delivery receipt, photographs of damage, and a written description of non-conformance. The supplier shall respond within 5 business days with a corrective action plan including replacement, credit, or remediation as appropriate.