TP2 Phosphorus-Deoxidized Copper Coil Tube
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd. | Product Code: No. 448
1. Product Overview
The TP2 Coil Tube is a precision-drawn, phosphorus-deoxidized pure copper coil tube manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Conforming to the international standard GB/T 5231 (Chinese National Standard) and equivalent to ASTM B152 and ISO 1182 designations, this product is engineered for demanding applications requiring superior electrical conductivity, thermal performance, and mechanical reliability. The coil form factor enables efficient downstream processing, including straightening, cutting, and further forming operations, while minimizing material waste and handling complexity.
The TP2 designation signifies a high-purity copper alloy with a minimum copper content of 99.90%, deoxidized with phosphorus to eliminate hydrogen embrittlement and enhance resistance to hot shortness during brazing and welding operations. This material is particularly valued in the coil tube segment for its combination of ductility, corrosion resistance, and consistent metallurgical properties across the entire coil length.
2. Material & Properties
2.1 Chemical Composition
| Element | Symbol | Specification (wt%) | Standard Reference |
|---|---|---|---|
| Copper (minimum) | Cu | ≥ 99.90 | GB/T 5231 |
| Phosphorus (deoxidizer) | P | 0.010 – 0.040 | GB/T 5231 |
| Iron | Fe | ≤ 0.020 | GB/T 5231 |
| Lead | Pb | ≤ 0.020 | GB/T 5231 |
| Antimony | Sb | ≤ 0.010 | GB/T 5231 |
| Arsenic | As | ≤ 0.010 | GB/T 5231 |
| Zinc | Zn | ≤ 0.010 | GB/T 5231 |
| Silver | Ag | ≤ 0.010 | GB/T 5231 |
| Gold | Au | ≤ 0.001 | GB/T 5231 |
| Oxygen (combined) | O | ≤ 0.020 | GB/T 5231 |
2.2 Physical Properties
| Property | Value | Test Method |
|---|---|---|
| Density (ρ) | 8.94 g/cm³ | GB/T 6388 |
| Electrical Conductivity (20°C) | ≥ 58.0 MS/m (100% IACS) | GB/T 22874 |
| Thermal Conductivity (20°C) | 398 W/(m·K) | ASTM E1461 |
| Thermal Expansion (20–100°C) | 16.5 × 10⁻⁶ /K | GB/T 6388 |
| Melting Point | 1083–1094 °C | — |
2.3 Mechanical Properties (Annealed Condition, M)
| Property | Specification | Test Method |
|---|---|---|
| Tensile Strength (Rm) | ≥ 220 MPa | GB/T 228.1 |
| 0.2% Proof Stress (Rp0.2) | ≥ 60 MPa | GB/T 228.1 |
| Elongation (A) | ≥ 40% | GB/T 228.1 |
| Hardness (HV) | ≤ 60 HV | GB/T 3894.2 |
| Flattening Test | Conforms to d = 10D | GB/T 247 |
3. Specifications
3.1 Dimensional Specifications
| Parameter | Range / Value | Tolerance |
|---|---|---|
| Outer Diameter (OD) | 3.0 mm – 50.0 mm | ±0.05 mm (≤ 12 mm); ±0.10 mm (> 12 mm) |
| Wall Thickness (WT) | 0.20 mm – 3.00 mm | ±10% of nominal |
| Inner Diameter (ID) | 2.6 mm – 46.0 mm | Derived from OD and WT |
| Coil Length | Up to 500 m per coil | ±2% (negotiable) |
| Coil Weight | Up to 2,000 kg per coil | — |
| Coil ID (Winding Diameter) | 76 mm / 152 mm / 254 mm | Standard options |
| Coil OD (Winding Diameter) | 400 mm – 800 mm | Dependent on specification |
3.2 Available Temper Conditions
| Designation | Condition | Tensile Strength | Typical Application |
|---|---|---|---|
| M | Annealed (Fully Soft) | ≥ 220 MPa | Deep drawing, forming |
| Y1 | 1/4 Hard | ≥ 280 MPa | General purpose |
| Y2 | 1/2 Hard | ≥ 320 MPa | Heat exchangers |
| Y3 | 3/4 Hard | ≥ 360 MPa | High-pressure systems |
| Y4 | Full Hard | ≥ 380 MPa | Spring applications |
3.3 Surface Finish Options
- Standard Bright Annealed: Clean, uniform surface with no oxidation discoloration
- Mirror Polished: Ra ≤ 0.4 μm, suitable for optical and decorative applications
- Electropolished: Ra ≤ 0.2 μm, enhanced corrosion resistance for food-grade and pharmaceutical use
- Brazed/Uncoated: Native surface condition for direct brazing operations
4. Manufacturing Process
The TP2 Coil Tube production process at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorously controlled multi-stage workflow to ensure consistent quality and dimensional accuracy:
- Copper Selection & Ingot Preparation: High-purity TP2 copper ingots (≥ 99.99% Cu) are sourced from certified smelters and verified through spectroscopic analysis (OES/XRF) prior to acceptance.
- Continuous Casting: Ingot material is cast into seamless copper rod using a precision continuous casting process, producing round bar stock with tight dimensional tolerances.
- Hot Rolling & Annealing: The cast rod undergoes hot rolling to reduce cross-sectional dimensions, followed by periodic annealing cycles at 650–700°C to maintain ductility and prevent work hardening.
- Wire Drawing / Rod Drawing: The preformed rod is cold-drawn through a series of progressively reducing tungsten carbide (WC) dies to achieve the target outer diameter with high surface quality.
- Pipe Forming (Seamless): The drawn rod is pierced and further drawn through matched die sets to produce seamless tubing with controlled wall thickness uniformity (±10%).
- Intermediate Annealing: Periodic solution annealing at controlled atmospheres (hydrogen-nitrogen mixture, dew point ≤ -60°C) eliminates residual stresses and restores full annealed properties.
- Final Cold Drawing: Precision drawing through calibrated tungsten carbide dies achieves final dimensional specifications with concentricity ≤ 0.1 mm.
- Final Annealing: Continuous tube annealing furnace operation in a controlled reducing atmosphere ensures uniform microstructure and eliminates drawing-induced residual stresses.
- Coiling: The annealed tube is wound onto precision coil spools with controlled tension to prevent deformation, kinking, or surface damage.
- Final Inspection & NDT: Comprehensive non-destructive testing (see Section 4.1) is performed on every coil before packaging and shipment.
4.1 Non-Destructive Testing (NDT) — Key Technical Research
A critical area of ongoing technical research at Wenzhou Jixing Metal Materials Co., Ltd. is the NDT Identification and Marking Technology for TP2 Coil Tubes (TP2盘管探伤标识关键技术研究). This research program addresses the unique challenges associated with inspecting coil-form tubing, where the continuous, wound configuration presents significant inspection accessibility and traceability challenges.
NDT Methods Employed:
- Eddy Current Testing (ECT): Automated high-frequency eddy current probes scan the entire tube length to detect surface cracks, seams, and subsurface defects. The system utilizes dual-frequency discrimination to differentiate between geometric variations and actual material discontinuities.
- Ultrasonic Testing (UT): Phased-array ultrasonic transducers perform wall thickness measurement and internal defect detection with resolution down to 0.05 mm. This is critical for verifying wall thickness uniformity across the entire coil.
- Visual & Dimensional Inspection: Automated optical inspection systems verify surface quality, dimensional conformance, and coil integrity at line speeds up to 30 m/min.
- Helium Leak Testing (for sealed sections): Applied where applicable to verify hermetic integrity of sealed tube sections.
NDT Identification Marking System:
The key innovation in the company's NDT research focuses on the development of a traceable identification and marking system that enables precise correlation between NDT data points and specific locations along the coil tube. This system includes:
- Positional Coding: Each coil is assigned a unique serial number with encoded positional markers at regular intervals (typically every 10 m), enabling exact location identification of any inspected segment.
- Data Integration: NDT results are digitally linked to the coil's positional code, creating a comprehensive quality traceability database that records defect type, severity, location, and disposition for every segment.
- Visual Marking: Approved coils receive laser-engraved or ink-jet marked identification bands at specified intervals, including coil number, heat number, inspection date, and inspector certification code.
- Digital Traceability: QR codes or DataMatrix codes are applied to coil packaging, linking directly to the full NDT report, material certificates, and dimensional inspection data.
Technical Significance: This NDT identification system represents a significant advancement in coil tube quality assurance, enabling manufacturers to achieve full traceability from raw material through final product delivery. It supports compliance with stringent industry standards including ASME B31.3, ISO 9001:2015, and PED 2014/68/EU requirements for pressure equipment.
5. Applications
The TP2 Coil Tube is a versatile product serving a wide range of industrial, commercial, and consumer applications:
5.1 Primary Applications
- Refrigeration & Air Conditioning (HVAC): Condenser tubes, evaporator coils, and refrigerant circuit tubing where high thermal conductivity and brazing compatibility are essential.
- Heat Exchangers: Shell-and-tube heat exchangers, plate heat exchangers, and air-cooled condensers in power generation, petrochemical, and process industries.
- Electrical & Electronics: Bus bars, transformer windings, electrical connector tubing, and shielding components requiring high electrical conductivity.
- Automotive Industry: Radiator cores, AC condenser tubing, and engine cooling system components.
- Plumbing & Water Systems: Hot and cold water supply lines, domestic plumbing, and hydronic heating systems.
- Medical & Pharmaceutical: Gas delivery tubing, medical equipment components, and pharmaceutical process piping (electropolished grades).
- Food & Beverage Industry: Dairy processing, brewing equipment, and food-grade liquid transfer systems.
- Power Generation: Boiler tubes, turbine cooling systems, and nuclear-grade applications (special order).