Stainless Steel Coil Tube (盘管 / Coiltube) — Technical Product Specification
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Product Catalog No.: 1332
Classification: Literature & Reference — Industrial Product Documentation
1. Product Overview
Stainless steel coil tubes (Coiltube) are continuous-length tubular products manufactured from austenitic, ferritic, duplex, or martensitic stainless steel grades and wound into coils for efficient handling, storage, and downstream processing. Unlike cut-length pipes, coil tubes are supplied in continuous spirals that facilitate automated forming, bending, welding, and machining operations, thereby minimizing material waste and reducing processing time significantly.
Wenzhou Jixing Metal Materials Co., Ltd. specializes in the supply of high-grade stainless steel coil tubes designed to meet stringent international standards for dimensional accuracy, mechanical performance, and corrosion resistance. These coil tubes serve as critical intermediate products in the fabrication of heat exchangers, fluid transport systems, structural components, and precision-engineered assemblies across multiple industrial sectors.
2. Material & Properties
2.1 Available Grades
- Austenitic Grades: AISI 304, 304L, 316, 316L, 316Ti, 321, 347
- Ferritic Grades: AISI 430, 409, 444
- Duplex Grades: 2205, 2507
- Martensitic Grades: AISI 410, 420, 440A, 440C
- Custom Grades: Available upon request per customer specifications
2.2 Mechanical Properties (Typical — Annealed Condition)
| Property | Grade 304 / 304L | Grade 316 / 316L | Grade 321 | Grade 2205 (Duplex) |
|---|---|---|---|---|
| Tensile Strength (MPa) | ≥ 515 | ≥ 515 | ≥ 485 | ≥ 550 |
| Yield Strength (MPa) | ≥ 205 | ≥ 205 | ≥ 170 | ≥ 450 |
| Elongation (%) | ≥ 40 | ≥ 40 | ≥ 40 | ≥ 25 |
| Density (g/cm³) | 8.00 | 8.03 | 7.98 | 7.80 |
| Maximum Service Temperature (°C) | 870 | 870 | 900 | 320 |
2.3 Chemical Composition (Typical, wt%)
| Grade | C (Max) | Cr | Ni | Mn | Si | S (Max) | Mo |
|---|---|---|---|---|---|---|---|
| 304 | 0.08 | 18.0–20.0 | 8.0–10.5 | 2.0 | 1.0 | 0.030 | — |
| 316 | 0.08 | 16.0–18.0 | 10.0–14.0 | 2.0 | 1.0 | 0.030 | 2.0–3.0 |
| 321 | 0.08 | 17.0–19.0 | 9.0–12.0 | 2.0 | 1.0 | 0.030 | Ti ≥ 5×C |
| 2205 | 0.030 | 22.0–23.0 | 4.5–6.5 | 1.5 | 0.5 | 0.020 | 3.0–3.5 |
3. Specifications
| Parameter | Specification / Range |
|---|---|
| Outer Diameter (OD) | 3.0 mm – 168.3 mm (custom sizes available) |
| Wall Thickness | 0.3 mm – 10.0 mm |
| Coil Length (Continuous) | 50 m – 500 m (depending on OD and wall thickness) |
| Coil Inner Diameter (Coil ID) | 150 mm – 600 mm |
| Surface Finish | No. 1 (Annealed & Pickled), 2B, 2D, BA (Bright Annealed), HL (Hairline), No. 4, Mirror (8K) |
| Heat Treatment Condition | Annealed (Solution Treated), Cold Worked, Half-Hard, Full-Hard |
| Dimensional Tolerance | Per ASTM A511 / A554 / ASME B36.19M / EN 10217-7 |
| End Condition | Plain cut, beveled, threaded, or custom per drawing |
| Packaging | Woven/wooden pallet with stretch film wrapping; moisture-proof inner lining; export-grade seaworthy packaging available |
| Applicable Standards | ASTM A511, ASTM A554, ASME B36.19M, EN 10217-7, GB/T 14976, GB/T 12771, JIS G3459 |
4. Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous multi-stage manufacturing process ensuring dimensional consistency, metallurgical integrity, and surface quality:
-
Raw Material Selection & Ingot Casting:
Virgin stainless steel ingots or continuous-cast slabs are procured from certified mills, with each heat accompanied by a mill test certificate (MTC) documenting chemical composition and heat treatment history.
-
Hot Rolling & Pickling:
Slabs are hot-rolled into seamless or welded pipe blanks. The oxide scale formed during hot rolling is removed through acid pickling (HNO₃/HF or H₂SO₄/HF blend), restoring the passive chromium oxide layer.
-
Tube Forming (Seamless or Welded):
- Seamless Route: Plug piercing → hot rolling → cold drawing / cold rolling
- Welded Route: Cold forming → TIG (Tungsten Inert Gas) or orbital welding → seam inspection
-
Solution Annealing:
Tubes are heated to 1010–1150°C and rapidly quenched to dissolve carbide precipitates, ensuring maximum corrosion resistance and ductility.
-
Coil Winding & Sizing:
Continuous-length tubes are wound onto mandrels of specified inner diameter, with tension-controlled winding to prevent kinking or ovality.
-
Surface Finishing:
Depending on the required finish grade, tubes undergo grinding, polishing, electrolytic polishing, or passivation treatment.
-
Quality Inspection & Testing:
Every coil lot undergoes hydrostatic pressure testing, ultrasonic flaw detection, dimensional measurement, and spectroscopic chemical analysis.
-
Packaging & Dispatch:
Finished coils are wrapped, palletized, and prepared for domestic or international shipment with appropriate documentation.
5. Applications
5.1 Primary Industrial Applications
- Heat Exchangers & Boilers: Coil tubes are ideal for spiral-wound heat exchangers, economizers, and boiler tubes where continuous forming is required.
- Oil & Gas Industry: Downhole tubing, wellhead components, and flow lines in corrosive or high-temperature environments (particularly 316L and duplex grades).
- Food & Beverage Processing: Sanitary-grade tubing for milk processing, brewing, and pharmaceutical fluid transfer systems (BA finish, 304/316L).
- Chemical Processing: Piping for acid, alkali, and solvent transport where Mo-bearing grades provide superior resistance to pitting and crevice corrosion.
- Aerospace & Automotive: Precision-formed tubing for hydraulic lines, exhaust systems, and structural brackets.
- Power Generation: Superheater tubes, condenser tubes, and feedwater lines in thermal and nuclear power plants.
- Marine & Offshore: Seawater cooling systems, desalination plant piping, and ballast systems.
- Medical Devices: Implant-grade tubing and surgical instrument components (requiring electropolished finish).
5.2 Coil-Specific Advantages
- Eliminates butt-weld joints present in cut-length pipe, reducing leak risk and inspection burden.
- Enables automated coiling into compact geometries (e.g., spiral coils, hairpin bends) with zero material loss.
- Reduces inventory carrying costs — one coil replaces dozens of cut-length pieces.
- Facilitates just-in-time manufacturing workflows.
6. Quality Certifications & Compliance
| Certification / Standard | Scope of Applicability |
|---|---|
| ISO 9001:2015 | Quality Management System — covers manufacturing, inspection, and supply chain |
| ISO 14001:2015 | Environmental Management System |
| ISO 45001:2018 | Occupational Health & Safety Management |
| EN 10204 3.1 | Material Test Certificate — inspection by authorized quality assurance body |
| ASTM A511 / A554 | Standard specifications for seamless and welded stainless steel tube |
| ASME B36.19M | Welded and seamless wrought stainless steel pipe dimensions |
| GB/T 14976 (Chinese Standard) | Seamless stainless steel tubes for fluid transport |
| GB/T 12771 (Chinese Standard) | Welded stainless steel tubes for general use |
| PED 2014/68/EU (CE Marking) | Pressure Equipment Directive compliance for pressure-containing applications |
| NACE MR0175 / ISO 15156 | Resistance to sulfide stress cracking in oil & gas service |
7. Unique Selling Points
Wenzhou Jixing Metal Materials Co., Ltd. distinguishes its stainless steel coil tube offerings through the following competitive advantages:
- Wide Grade & Size Coverage: Comprehensive inventory spanning OD 3 mm to 168.3 mm with wall thicknesses from 0.3 mm to 10.0 mm, covering austenitic, ferritic, duplex, and martensitic families.
- Continuous-Length Flexibility: Custom coil lengths up to 500 m enable zero-waste forming and reduce downstream welding operations.
- Multi-Surface Finish Options: From industrial No. 1 finish to high-polish 8K mirror finish, accommodating both functional and