Stainless Steel Coil Tube (Coiltube) — Technical Specification
1. Product Overview
The Stainless Steel Coil Tube (Coiltube), product code 1507, is a precision-engineered continuous coil tube manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is designed for demanding applications in HVAC (Heating, Ventilation, and Air Conditioning) systems, heat exchangers, and fluid distribution networks. The coil tube is supplied in a continuous helical form, enabling efficient installation, minimal joint requirements, and superior thermal and mechanical performance in variable indoor operating conditions.
This specification document draws upon advanced engineering principles related to the thermal performance of coil-based systems, including cooling capacity calculations under varying indoor conditions — a methodology that underscores the critical role of coil geometry, material properties, and flow dynamics in system efficiency.
2. Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, selected for its exceptional corrosion resistance, mechanical durability, and thermal conductivity. The following key material properties characterize the product:
- Base Material: Austenitic Stainless Steel (e.g., AISI 304 / AISI 316 / AISI 321)
- Corrosion Resistance: Excellent resistance to oxidation, pitting, and intergranular corrosion; suitable for aggressive chemical environments
- Thermal Conductivity: 14–16 W/(m·K) for 304 grade; optimized for efficient heat transfer in coil configurations
- Mechanical Strength: Yield strength ≥ 205 MPa; tensile strength ≥ 515 MPa (annealed condition)
- Operating Temperature Range: −196°C to +870°C (continuous service)
- Hygienic Surface Finish: Available in BA (Bright Annealed), 2B, or polished (Ra ≤ 0.8 μm) finishes
- Food & Pharmaceutical Grade Compliance: Suitable for potable water, food processing, and pharmaceutical applications
3. Technical Specifications
| Parameter | Specification |
|---|---|
| Product Code | 1507 |
| Product Name | Stainless Steel Coil Tube (Coiltube) |
| Material Grade | AISI 304 / 316 / 321 (customizable) |
| Outer Diameter (OD) | 6.0 mm – 50.8 mm (1/4" – 2") |
| Wall Thickness | 0.5 mm – 3.0 mm |
| Coil Length | Continuous coil; typical lengths 50 m – 500 m per coil |
| Coil Diameter | 500 mm – 1500 mm (customizable per application) |
| Tolerance (OD) | ±0.05 mm (precision grade) / ±0.10 mm (standard grade) |
| Surface Finish | 2B, BA, No.4 Brushed, Mirror Polish (Ra ≤ 0.4 μm) |
| End Form | Plain, Beveled, or Threaded (BSP / NPT) |
| Heat Treatment | Solution Annealed + Pickled & Passivated |
| Maximum Working Pressure | Up to 4.0 MPa (dependent on OD and wall thickness) |
| Delivery Form | Continuous Coil (Coiltube) / Straight Lengths (upon request) |
4. Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous multi-stage manufacturing process to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection: High-purity stainless steel strip (coil) sourced from certified mills, verified via spectroscopic analysis for chemical composition compliance.
- Slitting & Leveling: The master coil is slit to precise width specifications and leveled to eliminate residual stresses and ensure flatness.
- Forming & Coiling: The strip is formed into a tubular cross-section via precision roll-forming or seamless tube drawing, then coiled into a continuous helical configuration at controlled tension.
- Welding (if applicable): Longitudinal seams are welded using TIG (Tungsten Inert Gas) or orbital welding processes with 100% internal gas shielding (argon) to prevent oxidation.
- Solution Annealing: Tubes are annealed at 1050°C – 1150°C in a protective atmosphere to relieve stresses and restore full austenitic microstructure.
- Pickling & Passivation: Acid pickling removes oxide scale; passivation treatment forms a protective chromium oxide layer for enhanced corrosion resistance.
- Surface Finishing: Mechanical polishing or electropolishing is applied to achieve the required surface roughness and aesthetic quality.
- Quality Inspection: Dimensional measurement, hydrostatic pressure testing, surface defect inspection (magnetic particle or visual), and chemical analysis are performed.
- Coiling & Packaging: The finished coil tube is wound onto protective spools, wrapped in moisture-barrier packaging, and labeled with traceability documentation.
5. Applications
The Stainless Steel Coil Tube is engineered for a wide range of industrial and commercial applications:
- HVAC & Fan Coil Units: Serves as the heat transfer element in fan coil units (FCUs), where coil geometry and material thermal properties directly influence cooling capacity calculations under varying indoor temperature and humidity conditions. The continuous coil design minimizes pressure drop and maximizes heat exchange surface area.
- Heat Exchangers: Used in shell-and-tube, plate-fin, and air-to-water heat exchangers for industrial and commercial systems.
- Refrigeration & Air Conditioning: Evaporator and condenser coils for commercial refrigeration and split AC systems.
- Food & Beverage Processing: Sanitary fluid transfer lines, pasteurization equipment, and brewing systems requiring hygienic-grade tubing.
- Pharmaceutical & Medical: Clean-in-place (CIP) systems, steam distribution, and process fluid handling in GMP-compliant facilities.
- Chemical & Petrochemical: Corrosive fluid transport, heat tracing systems, and process instrumentation.
- Automotive & Aerospace: Fuel lines, brake lines, and hydraulic systems requiring high-performance tubing.
- Domestic Water Supply: Potable water distribution systems and hot water recirculation loops.
6. Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework to ensure product conformity with international standards:
- ISO 9001:2015 — Quality Management System (QMS)
- ISO 14001:2015 — Environmental Management System
- ISO 45001:2018 — Occupational Health & Safety Management
- ASME BPE — Bioprocessing Equipment (for pharmaceutical-grade products)
- EN 10204 3.1 — Material Test Certificate
- ASTM A269 / A270 — Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing
- GB/T 12771 — Chinese National Standard for Welded Stainless Steel Tubes for Fluid Transport
- NSF/ANSI 61 — Drinking Water System Components (where applicable)
Unique Selling Points: The Coil Tube product from Wenzhou Jixing Metal Materials Co., Ltd. distinguishes itself through: (1) continuous coil delivery eliminating field welding and joint-related failure points; (2) precision dimensional tolerances ensuring seamless integration into automated manufacturing lines; (3) multi-grade material availability accommodating diverse environmental and pressure requirements; (4) full traceability from raw material to finished product; and (5) engineering support for thermal performance optimization — including cooling capacity modeling under variable indoor operating conditions as referenced in the product's technical literature base.