Stainless Steel Coil Tube (盘管 / Coiltube) — Technical Product Specification
Product Reference No.: 1183
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
Stainless Steel Coil Tube (also referred to as Coiltube or Coiled Tubing) is a continuous-length tubular product formed by cold-drawing or hot-rolling processes into a continuous coil configuration. Unlike conventional cut-to-length seamless or welded pipes, coil tubes are supplied in long, uninterrupted coils, offering superior material utilization, reduced welding joints, and enhanced flexibility in downstream processing and installation.
Wenzhou Jixing Metal Materials Co., Ltd. specializes in the manufacturing and supply of high-grade stainless steel coil tubes designed for demanding industrial, energy, chemical, and automotive applications. The coil tube product line leverages advanced forming technology and stringent quality control protocols to deliver consistent dimensional accuracy, mechanical performance, and corrosion resistance.
2. Material & Properties
2.1 Available Grades
- Austenitic Grades: AISI 304 (UNS S30400), AISI 304L (UNS S30403), AISI 316 (UNS S31600), AISI 316L (UNS S31603), AISI 321 (UNS S32100)
- Duplex Grades: UNS S31803 (2205), UNS S32205
- Super Duplex Grades: UNS S32750 (2507)
- Ferritic & Martensitic Grades: Available upon request per customer specification
2.2 Mechanical Properties (Typical — Annealed Condition)
| Property | AISI 304 / 304L | AISI 316 / 316L | Duplex 2205 |
|---|---|---|---|
| Tensile Strength (Rm) | 515 – 730 MPa | 515 – 730 MPa | ≥ 550 MPa |
| Yield Strength (Rp0.2) | ≥ 205 MPa | ≥ 205 MPa | ≥ 450 MPa |
| Elongation (A50mm) | ≥ 40% | ≥ 40% | ≥ 25% |
| Hardness (HB) | ≤ 217 | ≤ 217 | ≤ 350 |
| Density (g/cm³) | 7.93 | 8.00 | 7.85 |
2.3 Corrosion Resistance
- Excellent resistance to atmospheric corrosion, dilute acids, and organic solvents
- 316L grade offers superior chloride pitting resistance (PREN ≥ 24)
- Duplex 2205 provides enhanced resistance to stress corrosion cracking (SCC) and chloride-induced pitting
- Non-magnetic in fully annealed condition (magnetic permeability ≤ 1.05 for austenitic grades)
3. Specifications
3.1 Dimensional Parameters
| Parameter | Range / Value |
|---|---|
| Outer Diameter (OD) | 6.0 mm – 114.3 mm (¼" – 4½") |
| Wall Thickness (WT) | 0.3 mm – 6.0 mm |
| Coil Length (per coil) | 50 m – 300 m (customizable) |
| Coil Inner Diameter (ID) | 150 mm – 400 mm |
| Coil Weight | Up to 3,000 kg per coil |
| OD Tolerance | ±0.05 mm – ±0.15 mm (per ASTM A213 / EN 10216) |
| WT Tolerance | ±10% of nominal thickness |
| Surface Finish | 2B (Cold Rolled & Annealed), BA (Bright Annealed), No. 4 Brushed, Mirror (8K) |
3.2 Applicable Standards
- ASTM A213 / A269 — Seamless and Welded Austenitic Stainless Steel Tubing
- EN 10216-5 — Heat-resistant, hygienic, and mechanical tubes — Welded stainless steel tubes
- ISO 3506 — Stainless steel seamless tubes for general purposes
- GB/T 14976 — Seamless steel tubes for fluid transport (Chinese National Standard)
- JIS G3459 — Stainless steel tubes for general use
4. Manufacturing Process
The production of high-quality stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a multi-stage manufacturing workflow:
- Material Preparation: Selection of certified stainless steel strip or bar stock conforming to the target grade specification. Incoming material undergoes spectroscopic verification (PMI — Positive Material Identification) to confirm chemical composition.
- Coil Forming: Cold-rolled strip is precision-formed into tubular geometry using high-speed roll-forming or autogenous welding processes. TIG (Tungsten Inert Gas) welding is employed for welded coil tubes, ensuring penetration integrity with argon shielding.
- Heat Treatment: Solution annealing (1050°C – 1150°C) followed by controlled cooling to homogenize microstructure, relieve residual stresses, and restore full corrosion resistance. Online induction heating technology may be applied for energy-efficient, localized heat treatment with minimal thermal distortion.
- Pickling & Passivation: Removal of oxide scale through acid pickling, followed by passivation treatment to form a protective chromium oxide layer (Cr₂O₃) on the surface.
- Surface Finishing: Mechanical polishing, chemical polishing, or electro-polishing to achieve specified surface roughness (Ra ≤ 0.4 μm for hygienic applications).
- Coiling & Packaging: Finished tubes are wound onto protective cores with interlayer padding. Each coil is wrapped in moisture-resistant film and labeled with mill test certificates (MTC).
5. Applications
5.1 Energy & Power Generation
- Boiler tubes and superheater elements in thermal power plants
- Heat exchanger tubes for condensers and feedwater heaters
- Steam generator tubing in nuclear applications
5.2 Chemical & Petrochemical Industry
- Process piping for aggressive chemical environments
- Reactor internals and catalyst support structures
- Corrosion-resistant heat exchangers and condensers
5.3 Automotive & Aerospace
- Exhaust system tubing (catalytic converter inlet/outlet)
- Fuel injection lines and hydraulic tubing
- Aerospace engine heat exchanger elements
5.4 Food, Beverage & Pharmaceutical
- Hygienic process piping (3-A and EHEDG compliant)
- CIP (Clean-in-Place) and SIP (Sterilize-in-Place) systems
- Milk processing, brewery, and bioreactor tubing
5.5 Oil & Gas / Offshore
- Subsea production tubing and flow lines
- Wellhead equipment and downhole instrumentation
- Heat exchangers in offshore platforms
6. Quality Certifications & Testing
6.1 Certifications
- ISO 9001:2015 — Quality Management System
- ISO 14001:2015 — Environmental Management System
- API 5CT / API 5L — Where applicable for oil & gas applications
- EN 10204 3.1 — Material Test Certificate per batch delivery
- CE Marking — Conformity with European pressure equipment directives
6.2 Quality Control Tests
| Test Method | Standard | Purpose |
|---|---|---|
| Hydrostatic Pressure Test | ASTM A213 / EN 10216 | Verification of weld integrity and pressure containment |
| Eddy Current Testing (ECT) | ASTM E309 | Detection of surface and near-surface defects in welded tubing |
| Positive Material Identification (PMI) | ASTM E1922 | Confirmation of alloy grade via XRF spectroscopy |
| Intergranular Corrosion Test | ASTM A923 Practice A | Assessment of sensitization resistance post-heat treatment |
| Tensile & Hardness Testing | ASTM A370 | Verification of mechanical properties per grade specification |
| Dimensional Inspection | ASTM A213 / EN 10216 | Confirmation of OD, WT, and straightness tolerances |
7. Unique Selling Points
Continuous-Length Supply: Coil tube format eliminates field welding requirements, reducing installation time and joint failure risk by up to 40% compared to cut-length alternatives.
- Advanced Online Induction Heating: Integration of energy-efficient induction heat treatment technology ensures uniform microstructure without the carbon footprint of traditional furnace annealing.
- Grade Versatility: Full spectrum from standard austenitic (304/316) to super duplex (2507), accommodating extreme service conditions from cryogenic to high-temperature.
- Hygienic & Precision Grades: Capable of delivering tubing with surface roughness as low as Ra 0.2 μm, suitable for pharmaceutical and semiconductor-grade applications.
- Custom Coiling Solutions: Flexible coil diameter, length, and packaging configurations tailored to customer-specific handling and downstream processing requirements.
- Full Traceability: Each coil is accompanied by a complete quality dossier including heat number, chemical analysis, mechanical test reports, and dimensional inspection records.
8. Packaging & Delivery
- Each coil wound on steel or wooden protective cores
- Interlayer kraft paper or PE foam padding to prevent surface damage
- Outer wrapping with VCI (Vapor Corrosion Inhibitor) film for moisture protection
- Shrink-wrapped and strapped for secure transport
- Available in sea-worthy export packaging upon request
For detailed quotation, sample requests, or technical consultation, contact Wenzhou Jixing Metal Materials Co., Ltd. directly. All products are manufactured in accordance with the highest international standards and are backed by comprehensive warranty and after-sales support.