Stainless Steel Spiral Coil Tube (Coiltube) — Product Technical Specification
1. Product Overview
The Stainless Steel Spiral Coil Tube (hereinafter referred to as "Coiltube") is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd., designed for continuous spiral winding applications in high-temperature and high-pressure environments. This product category encompasses both cold-rolled and hot-rolled stainless steel coils that are subsequently formed into helical or spiral geometries, suitable for integration into water wall systems, heat exchangers, and process piping assemblies.
The Coiltube product line is distinguished by its integration with advanced CCD (Charge-Coupled Device) based weld seam tracking systems, enabling real-time monitoring and correction of welding trajectories during the spiral coil welding process. This technology ensures uniform weld bead geometry, consistent penetration depth, and superior joint integrity across the entire coil length — a critical requirement for pressure-vessel-grade spiral coil water walls in power generation and petrochemical applications.
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive inventory and supply chain for stainless steel coil tubes conforming to international standards including ASTM (American Society for Testing and Materials), ASME (American Society of Mechanical Engineers), EN (European Norms), and GB (Chinese National Standards). The company's product catalog includes over 600 distinct coil tube configurations covering a wide range of diameters, wall thicknesses, and alloy grades.
2. Material Grades and Mechanical Properties
2.1 Available Alloy Grades
- 304 / 304L (UNS S30400 / S30403): General-purpose austenitic stainless steel offering excellent corrosion resistance in oxidizing environments, with a maximum service temperature of 870°C (1,598°F).
- 316 / 316L (UNS S31600 / S31603): Molybdenum-enhanced austenitic grade providing superior resistance to pitting and crevice corrosion, particularly in chloride-containing media. Maximum service temperature: 870°C (1,598°F).
- 321 (UNS S32100): Titanium-stabilized austenitic grade suitable for high-temperature service up to 900°C (1,652°F), with excellent resistance to intergranular corrosion.
- 310S (UNS S31008): High-temperature austenitic grade with outstanding oxidation resistance, serviceable up to 1,150°C (2,094°F) in reducing atmospheres.
- 347H (UNS S34708): Columbium-stabilized grade designed for high-temperature applications in boiler and furnace environments, with a maximum recommended service temperature of 870°C (1,598°F).
- 309 / 310 (UNS S30908 / S31008): Overlay and cladding grades for thermal barrier applications and extreme temperature environments.
2.2 Typical Mechanical Properties (Annealed Condition)
| Property | 304/304L | 316/316L | 321 | 310S | 347H |
|---|---|---|---|---|---|
| Tensile Strength (Rm) — MPa | ≥515 | ≥515 | ≥515 | ≥515 | ≥515 |
| Yield Strength (Rp0.2) — MPa | ≥205 | ≥205 | ≥205 | ≥205 | ≥205 |
| Elongation (A50) — % | ≥40 | ≥40 | ≥40 | ≥40 | ≥40 |
| Hardness (HV) — Max | ≤217 | ≤217 | ≤217 | ≤217 | ≤217 |
| Density — g/cm³ | 8.00 | 8.00 | 8.00 | 8.03 | 8.00 |
| Thermal Conductivity (at 100°C) — W/(m·K) | 16.3 | 16.3 | 16.3 | 21.5 | 16.3 |
| Thermal Expansion (20–100°C) — ×10⁻⁶/K | 17.3 | 17.3 | 17.3 | 18.0 | 17.3 |
2.3 Chemical Composition Requirements (Weight %)
| Grade | C (Max) | Si (Max) | Mn (Max) | P (Max) | S (Max) | Cr | Ni | Mo | Stabilizer |
|---|---|---|---|---|---|---|---|---|---|
| 304 | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 18.0–20.0 | 8.0–10.5 | — | — |
| 304L | 0.030 | 1.00 | 2.00 | 0.045 | 0.030 | 18.0–20.0 | 8.0–12.0 | — | — |
| 316 | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
| 316L | 0.030 | 1.00 | 2.00 | 0.045 | 0.030 | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
| 321 | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 17.0–19.0 | 9.0–12.0 | — | Ti ≥ 5×C |
| 310S | 0.08 | 1.50 | 2.00 | 0.045 | 0.030 | 24.0–26.0 | 19.0–22.0 | — | — |
| 347H | 0.08 | 1.00 | 2.00 | 0.045 | 0.030 | 18.0–20.0 | 9.0–13.0 | — | Cb+Ti ≥ 10×C |
3. Dimensional Specifications
3.1 Outer Diameter (OD) and Wall Thickness (WT) Range
| Parameter | Standard Range | Custom Range | Tolerance |
|---|---|---|---|
| Outer Diameter (OD) | φ6.0 – φ159.0 mm | φ3.0 – φ219.0 mm | ±0.5 mm (≤φ25), ±0.75 mm (>φ25) |
| Wall Thickness (WT) | 0.5 – 12.0 mm | 0.3 – 15.0 mm | ±10% of nominal |
| Coil Length per Spool | 100 – 1,200 m | Up to 2,000 m | — |
| Spiral Pitch | 15 – 500 mm | 10 – 800 mm | ±1.0 mm |
| Helix Diameter | 200 – 5,000 mm | 150 – 8,000 mm | ±2.0 mm |
| Surface Finish | 2B, No.1, BA, Custom | Per customer specification | Ra ≤ 0.8 μm (BA) |
3.2 Standard Pipe Size Designations
| NPS (Nominal Pipe Size) | OD — mm | Schedule 5S | Schedule 10S | Schedule 40S | Schedule 80S |
|---|---|---|---|---|---|
| 1/2" (DN15) | 15.88 | 1.65 | 2.77 | 2.77 | 3.73 |
| 3/4" (DN20) | 21.34 | 1.65 | 2.87 | 2.87 | 3.91 |
| 1" (DN25) | 26.67 | 1.65 | 2.77 | 3.05 | 3.68 |
| 1½" (DN40) | 42.16 | 1.65 | 2.77 | 3.68 | 4.78 |
| 2" (DN50) | 50.80 | 1.90 | 2.77 | 3.68 | 5.08 |
| 3" (DN80) | 76.10 | 2.11 | 3.05 | 5.49 | 7.82 |
| 4" (DN100) | 101.60 | 2.11 | 3.05 | 6.02 | 8.56 |
| 6" (DN150) | 154.05 | 2.77 | 3.40 | <