Sapphire Glass Tube — High Pressure Single-Crystal Al₂O₃ Tube
Sapphire Glass Tube — precision single-crystal Al₂O₃ tubes for high-pressure, high-temperature, and harsh-chemical sight/optical applications. Exceptional hardness, wide spectral transmission, and excellent thermal stability for demanding industrial and scientific uses.
Description
Lumistar specializes in the production of sapphire glass and high-pressure sapphire glass tubes. Sapphire has excellent optical properties, capable of transmitting deep ultraviolet, visible light, near infrared, and mid-wave infrared light from 0.18 to 5.5 μm.
Sapphire has outstanding mechanical strength, with a flexural strength of up to 850MPa, making it the preferred material for high-temperature and high-pressure glass view windows. Lumistar can calculate various pressure strengths under different temperature curves for users.
Lumistar can design and manufacture all kinds of high-temperature and high-pressure sapphire glass windows, sapphire glass tubes, and pressure-resistant windows to meet the pressure requirements of high vacuum to ultra-high pressure, 1E-13 to 150MPa, and can also be coated with waterproof film, oilproof film, AR anti-reflection film, and so on, according to the needs of users.
Maximum specifications available: diameter 400mm.
Key benefits
- Exceptional mechanical durability — single-crystal sapphire is extremely hard and scratch resistant (Mohs ≈ 9 / Vickers high), giving long service life in abrasive or high-wear applications.
- Wide optical window — sapphire transmits from roughly the deep-UV into the IR (commonly quoted ~150 nm up to ~5.5 μm depending on orientation and polish), enabling laser, UV, and IR optical paths through the tube.
- High temperature & pressure capability — high melting point and thermal stability allow sapphire tubes to operate in high-temperature environments and to be used as pressure windows or sight tubes with appropriate mounting.
- Chemical inertness — excellent resistance to acids, solvents, and many process chemicals; suitable for corrosive environments where polymer or borosilicate tubes fail.
- Low thermal expansion & good thermal conductivity — reduces thermal stress and helps maintain optical performance under thermal cycling.
Typical Applications
High-pressure sight tubes for petrochemical and R&D equipment; optical windows and laser feedthroughs; NMR and high-pressure cells; deep-water and subsea viewing ports; sensor protection tubes; high-temperature lamp sleeves and semiconductor process windows.
Typical Technical Specifications
| Material | Sapphire Glass | Borosilicate Glass | Quartz Glass | PMMA organic tube | Polycarbonate PC tube |
|---|---|---|---|---|---|
| Size | Custom sizes φ5–φ400mm |
Custom Sizes φ5–φ315mm |
Custom sizes φ5–φ800mm |
Custom sizes φ5–φ800mm |
Custom sizes φ5–φ800mm |
| Length | 10mm–2000mm | 10mm–3000mm | 10mm–3000mm | 10mm–3000mm | 10mm–3000mm |
| Shape | Cylindrical | Cylindrical Square Hole Type |
Cylindrical Square Hole Type |
Cylindrical Square Hole Type |
Cylindrical Square Hole Type |
| Thickness | 1mm–150mm | 1mm–20mm | 1mm–20mm | 1mm–20mm | 1mm–20mm |
| Temperature resistance | -196℃ / +1600℃ | -30℃ / +200℃ | -273℃ / +1100℃ | -20℃ / +100℃ | -40℃ / +100℃ |
| Pressure resistance | FV / +300 MPa | FV / +2.5 MPa | FV / +2.5 MPa | FV / +12 MPa | FV / +12 MPa |
| Use | High-temperature and high-pressure viewport pipes, chemical pipeline viewports | ||||
| Color | Transparent | ||||
| Features | High thermal resistance; resistant to high temperature, high pressure; explosion-proof | ||||
| Chemical Formula | Al2O3 |
|---|---|
| Crystal System | Trigonal |
| Class | Hexagonal-scalenohedral |
| Melting Temperature | 2050℃ |
| Thermal Expansion | Parallel to C-axis: 6.7 × 10-6 Perpendicular to C-axis: 5.0 × 10-6 |
| Specific Heat | 0.18 Cal/gm°K (25℃) |
| Density | 3.99–4.10 g/cm3 |
| Hardness | 9 (Moh’s scale) (Hv) ≥ 1700 kg/mm2 |
| Modulus of Elasticity | 340–380 GPa |
| Compressive Strength | 2.1 GPa |
| Tensile Strength | 0.19 GPa |
| Index of Refraction | Parallel to C-axis: 1.769 Perpendicular to C-axis: 1.760 |
| Index of IR Transmission | 3–5.5 µm ≥ 90% (coated with anti-reflective film) |
| Electrical Resistance | 1011/cm 106/cm 103/cm |
| Dielectric Constant | 7.5–10 |
| Corrosion Resistance | Cannot be corroded by acid or alkali at normal temperature; only corrosive to HF at 300℃ |
