Stainless Steel Short Coil Tube (30 m – 100 m/Coil)
1. Product Overview
The Stainless Steel Short Coil Tube (product designation: Coiltube Series, Catalog No. 41) is a precision-engineered austenitic stainless steel tubing supplied in compact coil configurations ranging from 30 metres to 100 metres per coil. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd., this product category is specifically engineered to address the logistical and installation challenges associated with short-run piping applications in confined industrial environments.
Unlike standard long-length coil tubes (which typically exceed 100 m per coil) or individual cut-length tubes, the short coil tube occupies a strategic middle ground in the product spectrum. The coiled format preserves material continuity while the reduced coil length (30–100 m) significantly reduces the overall coil diameter and weight, enabling single-operator manual handling without the need for heavy lifting equipment. This design philosophy directly translates into reduced installation labour costs, lower storage footprint requirements, and enhanced on-site flexibility for end users.
2. Material & Properties
Short coil tubes are typically produced from austenitic stainless steel grades conforming to international material standards. The most commonly offered grades include:
- SUS304 / AISI 304 / EN 1.4301 — General-purpose austenitic grade offering excellent corrosion resistance, weldability, and formability.
- SUS316 / AISI 316 / EN 1.4401 — Molybdenum-enhanced grade providing superior resistance to pitting and crevice corrosion in aggressive chemical environments.
- SUS304L / AISI 304L / EN 1.4307 — Low-carbon variant suitable for welding applications requiring reduced risk of intergranular corrosion.
- SUS316L / AISI 316L / EN 1.4404 — Low-carbon, molybdenum-bearing grade for demanding sanitary and pharmaceutical applications.
Key metallurgical properties of the base material include:
- Tensile Strength: ≥ 520 MPa (SUS304), ≥ 570 MPa (SUS316)
- Yield Strength (0.2% offset): ≥ 205 MPa (SUS304), ≥ 240 MPa (SUS316)
- Elongation at Break: ≥ 40%
- Corrosion Resistance: Resistance to atmospheric, acidic, and alkaline environments; resistance to stress corrosion cracking (SCC) in controlled chloride environments
- Operating Temperature Range: −196 °C to +870 °C (SUS304); −196 °C to +870 °C (SUS316)
- Surface Finish: 2B (mill finish), No. 4 (brushed), BA (bright annealed), or electropolished (Ra ≤ 0.4 μm) upon request
3. Specifications
| Parameter | Specification | Standard / Reference |
|---|---|---|
| Product Category | Stainless Steel Coil Tube — Short Coil (短盘) | — |
| Coil Length | 30 m – 100 m per coil | Supplier specification |
| Outer Diameter (OD) | Φ6.0 mm – Φ159.0 mm | ASTM A213 / EN 10216-5 / GB/T 12771 |
| Wall Thickness (WT) | 0.5 mm – 8.0 mm | ASTM A213 / EN 10216-5 / GB/T 12771 |
| OD Tolerance | ±0.05 mm (small diameter); ±0.1 mm (large diameter) | Supplier specification |
| WT Tolerance | ±0.03 mm (WT ≤ 1.0 mm); ±0.05 mm (WT > 1.0 mm) | Supplier specification |
| Coil Inner Diameter | Φ100 mm – Φ300 mm (varies with tube OD) | Supplier specification |
| Coil Outer Diameter | ≤ Φ600 mm (typical) | Supplier specification |
| Coil Weight | ≤ 250 kg per coil (typical, enabling manual handling) | Supplier specification |
| Material Grades | SUS304, SUS304L, SUS316, SUS316L, SUS321, SUS310S | ASTM / EN / GB |
| Surface Condition | 2B, No.4, BA, Electropolished (Ra ≤ 0.4 μm) | Supplier specification |
| End Condition | Open coil ends (unwelded) or weld-sealed upon request | Supplier specification |
| Packaging | Wooden crate / steel pallet with moisture-proof wrapping | Supplier specification |
| Applicable Standards | ASTM A213, ASTM A269, EN 10216-5, GB/T 12771, JIS G3459 | — |
4. Manufacturing Process
The production of stainless steel short coil tubes follows a rigorous, multi-stage manufacturing sequence designed to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Strip Preparation: Cold-rolled stainless steel strip is procured from certified mills and subjected to incoming inspection for composition (via optical emission spectroscopy, OES), surface condition, and mechanical properties.
- Forming (Pipe Milling): The strip is fed through a series of progressively reducing rolls in a cold-rolled forming mill. Precision-controlled roll gaps ensure consistent wall thickness and outer diameter throughout the entire production run.
- Seam Welding: The formed tube passes through a high-frequency induction welding (HFW) station where the seam edges are brought into intimate contact and fused using electromagnetic induction heating. The welding parameters (frequency, power, speed) are optimised for each material grade and tube dimension to achieve full-penetration welds with minimal heat-affected zone (HAZ) distortion.
- Pilot Welding (Optional): For small-diameter tubes (OD ≤ Φ25 mm), a pilot weld is applied along the seam to prevent gapping during subsequent heat treatment.
- Heat Treatment (Solution Annealing): The welded tube is passed through a high-temperature annealing furnace (typically 1050–1150 °C) followed by rapid water quenching. This process dissolves carbides precipitated during welding, restoring full austenitic microstructure and maximum corrosion resistance.
- Size Reduction (Sizing): The annealed tube passes through cold sizing rolls to achieve final dimensional tolerances (OD and WT) to within ±0.05 mm.
- Surface Finishing: Depending on the required specification, tubes may undergo pickling and passivation (to remove surface oxides and establish a protective chromium oxide layer), mechanical polishing, or electrolytic polishing.
- Coiling: The finished tube is wound onto a coil former to produce the target coil length of 30–100 m. Coil winding tension is carefully controlled to prevent permanent deformation or residual stress.
- Quality Inspection: Each coil undergoes ultrasonic testing (UT) for internal defects, eddy current testing (ECT) for surface and near-surface defects, dimensional measurement (OD, WT, straightness), and visual surface inspection.
- Packaging & Dispatch: Inspected coils are wrapped in moisture-proof material and secured in wooden crates or on steel pallets for shipment.
5. Applications
The short coil tube format is specifically designed for applications where compact supply coils offer distinct operational advantages. Key application domains include:
- Pharmaceutical & Biotechnology: Sanitary piping systems, CIP (Clean-In-Place) loops, and process connections in pharmaceutical manufacturing facilities where short runs and frequent system modifications are common.
- Food & Beverage Processing: Piping for dairy, brewing, and food processing plants requiring hygienic-grade tubing in compact plant layouts.
- Chemical & Petrochemical: Small-diameter instrument piping, control valve connections, and safety relief lines in chemical processing units with spatial constraints.
- Semiconductor & Electronics: Ultra-pure fluid delivery systems (UPFD) and chemical supply lines in semiconductor fabrication facilities.
- Medical Devices: Tubing components for medical gas systems, dialysis machines, and surgical equipment manufacturing.
- Automotive & Aerospace: Fuel lines, brake lines, and hydraulic circuits in vehicle and aircraft assembly where short, precisely coiled lengths reduce material waste.
- Architectural & Decorative: Handrails, balustrades, and decorative elements where short coil lengths facilitate on-site bending and fabrication.
- Heat Exchangers & Boilers: Small-bore tubes for compact heat exchanger assemblies, boiler tube banks, and HVAC systems.
6. Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring traceability and compliance across all product lines:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- EN 10204 3.1 — Material Test Reports (MTR) issued for every production batch
- ASTM A213 / A269 — Compliance with American material and product standards
- EN 10216-5 — Compliance with European seamless and welded stainless steel tube standards
- GB/T 12771 — Compliance with Chinese national standard for stainless steel seamless and welded tubes
- CE Marking — Conformity with European directives for pressure equipment (PED 2014/68/EU)
- 3-A Sanitary Standards — Certification for food-grade applications (upon request)
- Third-Party Inspection: Available from SGS, Bureau Veritas, or TÜV upon customer request
Each coil is accompanied by a Mill Test Certificate (MTC) documenting chemical composition, mechanical properties, heat treatment parameters, and non-destructive testing (NDT) results, providing full traceability from raw material to finished product.
7. Unique Selling Points
- Optimised Coil Length for Manual Handling: The 30–100 m coil length is specifically engineered to keep individual coil weight below 250 kg, enabling single-operator handling without forklifts or cranes. This reduces on-site equipment requirements and accelerates installation.
- Reduced Material Waste: Short coils minimise off-cut waste during fabrication, particularly for projects with multiple short-run requirements or variable routing needs.
- Enhanced Storage Flexibility: The compact coil dimensions (reduced coil outer diameter) allow storage in standard warehouse shelving and smaller loading bays, reducing inventory space requirements.
- Continuous Tube Integrity: Unlike cut-length tubes, coil tubes provide continuous material without butt welds, ensuring uniform mechanical properties and corrosion resistance along the entire length.
- Customisable Specifications: Tailored OD, WT, surface finish, and coil length within the 30–100 m range to match specific project requirements.
- Full Traceability: End-to-end quality documentation from mill certificate to shipment, supporting regulatory compliance in highly regulated industries.
Note: All specifications are subject to the applicable edition of the referenced international standards. Customers requiring non-standard dimensions, special surface finishes, or custom coil configurations should contact Wenzhou Jixing Metal Materials Co., Ltd. directly for engineering consultation and quotation. Material availability and lead times are subject to raw material market conditions.